Inligting

5.9C: Sulfaat- en swaelreduksie - Biologie

5.9C: Sulfaat- en swaelreduksie - Biologie



We are searching data for your request:

Forums and discussions:
Manuals and reference books:
Data from registers:
Wait the end of the search in all databases.
Upon completion, a link will appear to access the found materials.

Sulfaatreduksie is 'n tipe anaërobiese asemhaling wat sulfaat gebruik as 'n terminale elektronacceptor in die elektrontransportketting.

Leerdoelwitte

  • Gee 'n uiteensetting van die proses van sulfaat- en swaelreduksie, insluitend die verskillende doeleindes daarvan

Kern punte

  • Sulfaatvermindering is 'n noodsaaklike meganisme vir bakterieë en archaea wat in suurstofverarmde, sulfaatryke omgewings woon.
  • Sulfaatverminderaars kan organotrofies wees en koolstofverbindings gebruik, soos laktaat en pyruvat as elektrondonore, of litotrofies, en gebruik waterstofgas (H2) as 'n elektronskenker.
  • Voordat sulfaat as 'n elektronaanvaarder gebruik kan word, moet dit geaktiveer word deur ATP -sulfurylase, wat ATP en sulfaat gebruik om adenosien 5' -fosfosulfaat (APS) te skep.
  • Sulfaatverminderende bakterieë kan teruggevoer word tot 3,5 miljard jaar gelede en word beskou as een van die oudste vorme van mikroörganismes, wat bygedra het tot die swawelsiklus kort nadat lewe op aarde ontstaan ​​het.
  • Giftige waterstofsulfied is een afvalproduk van sulfaatverminderende bakterieë, en is die bron van die vrot eierreuk.
  • Sulfaat-verminderende bakterieë kan gebruik word om besmette gronde op te ruim.

Sleutel terme

  • litotrofies: Verkry elektrone vir asemhaling van anorganiese substrate.
  • organotrofies: Verkry elektrone vir respirasie vanaf organiese substrate.

Sulfaatreduksie is 'n tipe anaërobiese respirasie wat sulfaat as 'n terminale elektronontvanger in die elektronvervoerketting gebruik. In vergelyking met aërobiese respirasie, is sulfaatvermindering 'n relatief energieke swak proses, hoewel dit 'n noodsaaklike meganisme is vir bakterieë en archaea wat in suurstofarme, sulfaatryke omgewings leef.

Baie sulfaatreduktors is organotrofies en gebruik koolstofverbindings, soos laktaat en piruvaat (onder vele ander) as elektronskenkers, terwyl ander litotrofies is en waterstofgas gebruik (H)2) as elektronskenker. Sommige ongewone outotrofe sulfaat-verminderende bakterieë (bv. Desulfotignum phosphitoxidans) kan fosfiet (HPO3-) as 'n elektronskenker, terwyl ander (bv. Desulfovibrio sulfodismutans, Desulfocapsa thiozymogenes, en Desulfocapsa sulfoexigens) kan swael disproportioneer (een verbinding in twee verskillende verbindings verdeel, in hierdie geval 'n elektrondonor en 'n elektronaanvaarder) met behulp van elementêre swael (S0), sulfiet (SO32−) en tiosulfaat (S.2O32−) om beide waterstofsulfied (H2S) en sulfaat (SO42−).

Voordat sulfaat as elektronaanvaarder gebruik kan word, moet dit geaktiveer word. Dit word gedoen deur die ensiem ATP-sulfurylase, wat ATP en sulfaat gebruik om adenosien 5'-fosfosulfaat (APS) te skep. APS word daarna verminder tot sulfiet en AMP. Sulfiet word dan verder tot sulfied gereduseer, terwyl AMP in 'n ADP verander word met 'n ander ATP -molekule. Die algehele proses behels dus 'n belegging van twee molekules van die energiedraer ATP, wat van die vermindering herwin moet word.

Alle organe wat sulfaat verminder, is streng anaërobes. Omdat sulfaat energiestabiel is, moet dit deur adenylering geaktiveer word om APS (adenosine 5'-fosfosulfaat) te vorm om APS te vorm voordat dit gemetaboliseer kan word, en sodoende ATP verbruik. Die APS word dan verminder deur die ensiem APS reduktase om sulfiet te vorm (SO32−) en AMP. By organismes wat koolstofverbindings as elektronskenkers gebruik, word die ATP wat verbruik word, verreken deur fermentasie van die koolstofsubstraat. Die waterstof wat tydens fermentasie geproduseer word, is eintlik wat asemhaling tydens sulfaatreduksie aandryf.

Sulfaatverminderende bakterieë kan teruggevoer word tot 3,5 miljard jaar gelede en word beskou as een van die oudste vorme van mikroörganismes, wat bygedra het tot die swawelsiklus kort nadat lewe op aarde ontstaan ​​het. Sulfaatverminderende bakterieë kom algemeen voor in anaërobiese omgewings (soos seewater, sediment en water wat ryk is aan verrottende organiese materiaal) waar dit help met die agteruitgang van organiese materiale. In hierdie anaërobiese omgewings onttrek fermenterende bakterieë energie uit groot organiese molekules; die gevolglike kleiner verbindings (soos organiese sure en alkohole) word verder geoksideer deur asetogene, metanogene en die mededingende sulfaat-verminderende bakterieë.

Baie bakterieë verminder klein hoeveelhede sulfate om swaelbevattende selkomponente te sintetiseer; dit staan ​​bekend as assimilerende sulfaatreduksie. Daarteenoor verminder sulfaat-verminderende bakterieë sulfaat in groot hoeveelhede om energie te verkry en verdryf die resulterende sulfied as afval; dit staan ​​bekend as “dissimilerende sulfaatreduksie. ” Die meeste sulfaatverminderende bakterieë kan ook ander geoksideerde anorganiese swaelverbindings, soos sulfiet, tiosulfaat of elementêre swael (wat tot sulfied as waterstofsulfied gereduseer word) verminder.

Giftige waterstofsulfied is een afvalproduk van sulfaatverminderende bakterieë; die geur van vrot eier is dikwels 'n aanduiding vir die teenwoordigheid van sulfaat-verminderende bakterieë in die natuur. Sulfaatverminderende bakterieë is verantwoordelik vir die swaelagtige reuke van soutmoerasse en moddervlaktes. Baie van die waterstofsulfied sal met metaalione in die water reageer om metaalsulfiede te produseer. Hierdie metaalsulfiede, soos ystersulfied (FeS), is onoplosbaar en dikwels swart of bruin, wat lei tot die donker kleur van slik. Die swart kleur van slyk op 'n dam is dus te wyte aan metaalsulfiede wat voortspruit uit die werking van sulfaatverminderende bakterieë.

Sommige bakterieë wat sulfaat verminder, speel 'n rol in die anaërobiese oksidasie van metaan (CH4+ SO42- → HCO3– + HS– + H2O). 'N Belangrike fraksie van die metaan wat deur metanogene onder die seebodem gevorm word, word geoksideer deur bakterieë wat sulfate verminder in die oorgangsone wat die metanogenese van die sulfaatreduksie-aktiwiteit in die sedimente skei. Hierdie proses word ook beskou as 'n belangrike sink vir sulfaat in mariene sedimente. In hidrobrekingsvloeistowwe wat gebruik word om skalieformasies te breek om metaan (skaliegas) te herwin, word biosiedverbindings dikwels by water gevoeg om die mikrobiese aktiwiteit van sulfaatverminderende bakterieë te inhibeer om anaërobiese metaanoksidasie te vermy en om potensiële produksieverlies te minimaliseer.

Sulfaatverminderende bakterieë skep dikwels probleme wanneer metaalstrukture aan sulfaatbevattende water blootgestel word. Die interaksie van water en metaal skep 'n laag molekulêre waterstof op die metaaloppervlak. Sulfaat-verminderende bakterieë oksideer hierdie waterstof, wat waterstofsulfied skep, wat bydra tot korrosie. Waterstofsulfied van sulfaat-verminderende bakterieë speel ook 'n rol in die biogene sulfiedkorrosie van beton, en versuur ru-olie.

Sulfaat-verminderende bakterieë kan gebruik word vir die skoonmaak van besmette gronde; sommige spesies is in staat om koolwaterstowwe te verminder, soos benseen, tolueen, etielbenseen en xileen. Sulfaat-verminderende bakterieë kan ook 'n manier wees om suur mynwater te hanteer.


Ontwrig die kompleksiteit en diversiteit van kruisspraak tussen swael en ander minerale voedingstowwe in verboude plante

'N Volledige begrip van ionome homeostase vereis 'n deeglike ondersoek na die dinamika van die voedingsnetwerke in plante. Hierdie oorsig fokus op die kompleksiteit van interaksies tussen S en ander voedingstowwe, en dit word behandel op die vlak van die hele plant, die individuele weefsels en die sellulêre kompartemente. Wat makrovoedingstowwe betref, werk S-tekort hoofsaaklik deur plantegroei te verminder, wat weer die wortelopname van byvoorbeeld N, K en Mg beperk. Omgekeerd verminder tekorte in N, K of Mg die opname van S. TOR (teiken van rapamisien) proteïenkinase, wie se betrokkenheid by die ko-regulering van C/N en S metabolisme onlangs ontrafel is, bied 'n leidraad om die skakels te verstaan tussen S en plantgroei. By peulgewasse kan die oorspronklike kruising tussen N en S gevind word op die vlak van knoppies, wat hoë vereistes vir S toon, en dus spesifiek 'n aantal sulfaatvervoerders uitdruk. Met betrekking tot mikrovoedingstowwe, behalwe Fe, kan die opname daarvan onder S -tekort verhoog word deur verskillende meganismes. Een hiervan is die gevolg van die breë spesifisiteit van wortelsulfaatvervoerders wat opgereguleer word tydens S-tekort, wat ook sommige kan opneem. molibdat en seleneer. 'N Tweede meganisme is gekoppel aan die groot ophoping van sulfaat in die blaarvakuole, met die verminderde osmotiese bydrae onder S -tekort wat vergoed word deur 'n toename in Cl -opname en ophoping. 'n Derde groep breër meganismes wat ten minste sommige van die interaksies tussen S en mikrovoedingstowwe kan verklaar, gaan oor metaboliese netwerke waar verskeie voedingstowwe noodsaaklik is, soos die sintese van die Mo ko-faktor benodig deur sommige noodsaaklike ensieme, wat S, Fe, Zn en Cu benodig vir die sintese daarvan, en die sintese en regulering van Fe-S-klusters. Ten slotte kyk ons ​​kortliks na die onlangse ontwikkelings in die modellering van S-reaksies in gewasse (verdeling tussen plantdele en verspreiding van minerale versus organiese vorms) om perspektiewe te bied op voorspellingsgebaseerde benaderings wat die interaksies met ander minerale soos N in ag neem .

G. Courbet, K. Gallardo, G. Vigani, S. Brunel-Muguet, J. Trouverie, C. Salon en A. Ourry, die kompleksiteit en diversiteit van kruistalk tussen swael en ander minerale voedingstowwe in verboude plante ontbloot, Journal of eksperimentele plantkunde, 2019, 70, 4183-4196.


Omgewingsbiotegnologie en veiligheid

Abstrak

Mikrobiese dissimilerende sulfaatreduksie koppel die oksidasie van verminderde organiese of anorganiese verbindings met die vermindering van sulfaat of ander geoksideerde swaelverbindings, wat sulfied as metaboliese produk produseer. By die anaërobiese behandeling van afvalwater wat organiese materiaal en sulfaat bevat, soos dié van fermentasie-, stysel- of pulp- en papierbedrywe, kompeteer sulfaatverminderaars met die ander mikrobiese trofiese groepe wat betrokke is by die anaërobiese afbraak vir substrate. Dit lei tot 'n verlaagde metaan-opbrengs, benewens die besoedeling van die biogas met sulfied. Boonop is sulfied onheilspellend, korrosief en giftig. Hierdie proses maak nietemin voorsiening vir die verwydering van geoksideerde swaelverbindings uit afvalwater, in kombinasie met sulfiedverwyderingstegnieke. Vir nie-versuurde afvalwater kan 'n tweefase anaërobiese behandelingstelsel die moontlike probleme wat deur sulfaatreduksies veroorsaak word, verminder, en die werking van die eerste fase by laer pH kan 'n goedkoper en omgewingsvriendeliker proses tot gevolg hê.

Hierdie artikel fokus op die anaërobiese behandeling van nie-versuurde organiese sulfaatryke afvalwater, met die klem op die eerste stap van 'n tweefase-behandelingstelsel. Dit bevat mikrobiese mededingingsaspekte en relevante toksisiteitseffekte, soos pH, sulfied en vlugtige vetsure.


Ekologie:

Swaelverminderende bakterieë en argeë word oral versprei oor swaelbevattende mariene en terrestriële omgewings (Brock et al. 2009), en neem die ekologiese nis van respiratoriese S⁰ in anaërobies (Sorokin et al. 2010), of mikro -aeroofiele omgewings (Alain et al. 2009) in beslag. . Dit is opmerklik dat SRB geneig is om in baie van dieselfde habitatte as sulfaatverminderende bakterieë te leef (Brock et al. 2009).

Omgewings waaruit SRB geïsoleer is, sluit in suur warmwaterbronne (Yoneda et al. 2012), hidrotermiese vents (Alain et al. 2009), hipersoute mere (Sorokin et al. 2010), ondersese termiese bronne (Belkin et al. 1985), anaërobiese mariene modder sedimente (Pfennig, en Biebl 1976), en anoksiese modder van varswater swaelbronne (Finster et al. 1997a).

Aangesien sekere omgewings waarin swaelreduserende bakterieë en archaea leef, ekstremofiel is, kan pH- en temperatuuroptima dus gebruik word om S⁰-verminderers in uiters, en matig asidofiele subgroepe te klassifiseer (Schauder et at. 1993). Eersgenoemde bestaan ​​slegs uit archaea van verskillende genera, waaronder Acidianus, Desulfurolobus en Stygiolobus woon in 'n lae pH (2 tot 3) en hoë temperatuur (80⁰ tot 90⁰C) omgewings (Schauder et. 1993). Laasgenoemde groep bestaan ​​uit die matig asofiliese archaea en SRB wat in effens alkaliese (pH tot 8,5) en matige temperatuur (30⁰ tot 80⁰C) omgewings woon (Schauder et. 1993). Die groot diversiteit en oorvloed ekstremofiele S⁰ -reduktore kan te wyte wees aan die feit dat S⁰ meer oplosbaar is by hoë temperatuur, en daarom makliker toeganklik as elektronaanvaarder vir groepe wat in hoë temperatuuromgewings woon (Schauder et. 1993).

In anoksiese moddersedimentomgewings vorm SRB dikwels assosiasies met ander bakterieë wat H oksideer2S tot S⁰ veral groenswaelbakterieë (GSB) wat die SRB van S⁰ voorsien (Pfennig en Biebl 1976). SRB verlaag dan die S⁰ terug na H2S wat die GSB as hul elektronskenker kan gebruik (Brock et al 2009).

In hidrotermiese ontluchtingsgemeenskappe Epsilonproteobakterieë SRB kan gevind word as vrylewende organismes op of rondom uitlaatskoorstene, of pluime, of as endosimbionts van diere soos buiswurms en garnale (Alain et al. 2009 Brock et al. 2009). Die metaboliese S⁰ -vermindering wat deur SRB uitgevoer word, help om skadelike sulfiedverbindings te ontgift, waardeur hul endosimbiotiese gasheerorganismes in andersins giftige omgewings kan leef (Brock et al. 2009). As gevolg van hul hoë oorvloed en gespesialiseerde metaboliese aktiwiteite Epsilonproteobakterieë Daar word vermoed dat SRB 'n belangrike rol speel in die biogeochemiese siklus van die diepsee-swael (Alain et al. 2009).


Inhoud

Dit is bekend dat swaelverminderaars ongeveer 74 geslagte binne die bakteriedomein dek. [2] [7] [8] [9] [10] [1] Verskeie tipes swaelverminderende bakterieë is in verskillende habitatte ontdek, soos diep en vlak see hidrotermiese ventilasieopenings, varswater, vulkaniese suur warmwaterbronne en ander. [11] Volgens NCBI-klassifikasie behoort baie swaelverminderaars tot die filum van Proteobacteria, veral die klasse Deltaproteobacteria (Desulfuromonas, Pelobacter, Desulfurella, Geobacter), Gammaproteobacteria en Epsilonproteobacteria (nou ook bekend as die filum Campylobacterota [12] [13] volgens GTDB-klassifikasie). Ander filums wat swael-verminderende bakterieë bevat, is: Firmicutes (Desulfitobacterium, Ammonifex en Carboxydothermus), Aquificae (Desulfurobacterium en Aquifex), Synergistetes (Dethiosulfovibrio), Deferribacteres (Geovibrio), Thermodesulfobacteria, Spirochaetes en Chrysiogenetes. [1] [2]

Persephonella (guaimasensis, jachthaven), Thermocrinis (ruber), Thermosulfidibacter (takaii),

Thermovibrio (ammonificans, guaymasensis, ruber)

Desulfitibacter (alkalitolerans), Desulfitispora (alkaliphila), Desulfitobacterium (hafniense, chlororespirans, dehalogenans, metallireducens),

Desulfosporosinus (acididurans, acidiphilus, orientis, meridiei, auripigmenti), Desulfotomaculum (thermosubterraneus, salinum,

geothermicum, reducens, intricatum), Ercella (succinogenes), Halanaerobium (congolense), Halarsenatibacter (silvermanii),

Sporanaerobacter (acetigenes), Thermoanaerobacter (sulfurophilus)

Desulfomonile (tiejei), Desulfonatronovibrio (thiodismutans), Desulfonatronum (thioautotrophicum), Desulfovermiculus (halophilus),

Desulfovibrio, Desulfurella, Desulfurivibrio (alkaliphilus), Desulfuromonas, Desulfuromusa, Geoalkalibacter (ondergronds), Geobacter,

Seekoei (maritima), Pelobacter

Thioreductor (incertae sedis), Wolinella (succinogenes)

Thermanaerovibrio (acidaminovorans, velox), Thermovirga (lienii),

Mesotoga (infera, prima), Petrotoga (mexicana, miotherma, mobilis), Thermosipho (aficanus), Thermotoga (lettingae, maritima, naphthophila, neapolitana),

Nautilia, Nitratiruptor, Sulfurimonas, Sulfurospirillum,

Swaelverminderingsmetabolisme is 'n ou proses wat in die diep takke van die filogenetiese boom gevind word. [15] Swaelvermindering gebruik elementêre swael (S0) en genereer waterstofsulfied (H2S) as die hoof eindproduk. Hierdie metabolisme is groot teenwoordig in uiterste omgewings, vanwaar mikro -organismes meestal in die afgelope jare geïsoleer is, wat nuwe belangrike inligting verskaf. [2]

Baie swaelverminderende bakterieë is in staat om ATP te produseer deur litotrofiese swaelaspirasie, deur gebruik te maak van nulvalensie swael as elektronaannemer, byvoorbeeld die genera Wolinella, Ammonifex, Desulfuromonas en Desulfurobacterium. Aan die ander kant is daar verpligte fermenteerders wat byvoorbeeld elementêre swael kan verminder Thermotoga, Thermosipho en Fervidobacterium. Onder hierdie fermenteerders is daar spesies, soos Thermotoga maritina, wat nie afhanklik is van swaelreduksie nie, en gebruik dit as 'n aanvullende elektronsink. [10] Sommige navorsing [10] [16] [17] stel die hipotese voor dat polisulfied 'n intermediêre van swaelrespirasie kan wees, as gevolg van die omskakeling van elementêre swael in polisulfied wat in sulfiedoplossings voorkom, wat hierdie reaksie uitvoer:

Proteobacteria wysig

Die Proteobakterieë (van die Griekse God "Proteus", wat verskillende vorms kan aanneem) is 'n belangrike filum van alle gram-negatiewe bakterieë. Daar is 'n wye verskeidenheid metabolisme. Die meeste lede is fakultatief of verpligtend anaërobies, chemo-outotrofe en heterotrofies. Baie is in staat om te beweeg met behulp van flagella, ander is nie -beweeglik. [18] Hulle word tans in ses klasse verdeel, waarna verwys word met die Griekse letters alfa tot zeta, gebaseer op rRNA-volgordes: Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Deltaproteobacteria, Epsilonproteobacteria, Zetaproteobacteria. [8] [19]

Klas Gammaproteobakterieë Wysig

Die Gammaproteobacteria -klas bevat verskeie medies, ekologies en wetenskaplik belangrike groepe bakterieë. Hulle is groot organismes in uiteenlopende mariene ekosisteme en selfs uiterste omgewings. Hierdie klas bevat 'n groot verskeidenheid taksonomiese en metaboliese diversiteit, insluitend aërobiese en anaërobiese spesies, chemolitoauthotrofe, chemoorganotrofiese en fototrofiese spesies en ook vrye lewe, biofilmsvormers, kommensale en simbiote. [20]

Acidithiobacillus spp. Redigeer

Acidithiobacillus is chemolito-outrofiese, Gram-negatiewe padvormige bakterieë, wat energie gebruik deur die oksidasie van yster en swael wat minerale bevat vir groei. Hulle kan by 'n uiters lae pH (pH 1-2) leef en stel koolstof en stikstof uit die atmosfeer vas. Dit los koper en ander metale uit gesteentes op en speel 'n belangrike rol in die biogeochemiese siklus van voedingstowwe en metaal in suuromgewings. [21] Acidithiobacillus ferrooxidans is volop in natuurlike omgewings wat verband hou met piritiese ertsliggame, steenkoolneerslae en die versuurde dreinering daarvan. Dit verkry energie deur die oksidasie van gereduseerde swaelverbindings en dit kan ook ysterioon en elementêre swael verminder en sodoende die herwinning van yster en swaelverbindings onder anaërobiese toestande bevorder. Dit kan ook CO2 en stikstof regmaak en 'n primêre produsent van koolstof en stikstof in suur omgewings wees. [22]

Shewanella spp. Redigeer

Shewanella is Gram-negatiewe, beweeglike basille. Die eerste beskrywing van die spesie is in 1931 verskaf, Shewanella putrefaciens, 'n nie-fermentatiewe basille met 'n enkele polêre flagellum wat goed groei op konvensionele vaste media. Hierdie spesie is patogenies vir mense, selfs al is infeksies skaars en word dit veral aangemeld in die geografiese gebied wat deur warm klimate gekenmerk word. [23]

Pseudomonas spp. Redigeer

Pseudomonas is Gram-negatiewe chemoorganotrofiese Gammaproteobakterieë, reguit of effens geboë staafvormig. Hulle is in staat om te beweeg danksy een of meer polêre flagella wat selde onbeweeglik is. Aërobies, met 'n streng respiratoriese tipe metabolisme met suurstof as die terminale elektronacceptor, in sommige gevalle, wat anaërobies groei toelaat, kan nitraat as 'n alternatiewe elektronacceptor gebruik word. Byna al die spesies groei nie onder suur toestande nie (pH 4,5 of laer). Pseudomonas is wyd versprei in die natuur. Sommige spesies is patogeen vir mense, diere of plante. [24] Tipe spesies: Pseudomonas mendocina.

Klas Deltaproteobakterieë Redigeer

Die Deltaproteobakterieë Die klas bestaan ​​uit verskeie morfologies verskillende bakteriegroepe, gramnegatief, nie-vormend wat anaërobiese of aërobiese groei toon. Hulle is alomteenwoordig in mariene sedimente en bevat die meeste van die bekende swaelverminderende bakterieë (bv. Desulfuromonas spp.). Die aërobiese verteenwoordigers kan ander bakterieë verteer en verskeie van hierdie lede is belangrike bestanddele van die mikroflora in grond en water. [25]

Desulfuromusa spp. Redigeer

Desulfuromusa genus bevat bakterieë wat anaërobies verplig is en wat swael gebruik as 'n elektronaanvaarder en kortkettingvetsure, dikarboksielsure en aminosure, as elektronskenkers wat heeltemal geoksideer word. geboë of staafvormig. Drie swaelverminderende spesies is bekend, Desulfromusa kysingii, Desulfuromusa bakii en Desulfuromusa succinoxidans . [26]

Desulfurella spp. Redigeer

Desulfurella is kort staafvormige, gram-negatiewe selle, beweeglik danksy 'n enkele polêre flagellum of onbeweeglik, nie-spoorvormend. Onaangesien anaërobies, matig termofiel, kom dit gewoonlik voor in warm sedimente en in termies verhitte sianobakteriese of bakteriese gemeenskappe wat ryk is aan organiese verbindings en elementêre swael. Tipe spesies: Desulfurella acetivorans. [27]

Hippea spp. Redigeer

Hippea spesies is matige termofiele neutrofiele tot matige asidofiele, verpligte anaërobe swaelverminderende bakterieë met gram-negatiewe staafvormige selle. Hulle kan litotrofies groei met waterstof en swael en heeltemal vlugtige vetsure, vetsure en alkohole oksideer. Hulle bewoon duikbote se warm vents. Die tipe spesie is Hippea maritima. [28]

Desulfuromonas spp. Redigeer

Desulfuromonas spesies is gram-negatiewe, mesofiele, verpligte anaërobiese en volledige oksideerders [1] swawelverminderende bakterieë. Hulle kan groei op asetaat as enigste organiese substraat en verminder elementêre swael of polisulfied tot sulfied. [29] Tans bekende spesies van die genus Desulfuromonas is Desulfuromonas asetoksidane, Desulfuromonas acetexigens, die mariene organisme Desulfuromonas palmitate en Desulfuromonas thiophila.

  • Desulfiromonas thiophila is 'n verpligte anaërobiese bakterie wat swael as enigste elektronaannemer gebruik. Vermenigvuldiging deur binêre splitsing en selle is beweeglik danksy polêre flagella. Hulle leef in anoksiese modder van varswater swaelbronne, by 'n temperatuur van 26 tot 30°C en pH 6,9 tot 7,9. [30]
Geobacter spp. Redigeer

Geobacter -spesies het 'n respiratoriese metabolisme, met Fe (III) wat in alle spesies die algemene terminale elektronaanvaarder is.

  • Geobacter sulfurreducens is geïsoleer uit 'n dreineringssloot in Norman, Oklahoma. Dit is staafvormig, gram-negatief, nie-beweeglik en nie-spoorvormend. Die optimale temperatuur is 30 tot 35 °. Oor die metabolisme is streng anaërobiese chemoorganotrofe wat asetaat oksideer met Fe (III), S, Co (III), fumaraat of malaat as elektronaanvaarder. Waterstof word ook gebruik as 'n elektronskenker vir die vermindering van Fe (III), terwyl ander karboksielsure, suikers, alkohole, aminosure, gisekstrak, fenol en benzoaat nie. C-tipe sitochrome is in selle gevind. [31]
Pelobacter spp. Redigeer

Pelobacter is 'n unieke groep fermentatiewe mikroörganismes wat tot die klas Deltaproteobacteria behoort. Hulle verbruik fermentatief alkohol, soos 2,3-butaandiol, asetoïen en etanol, maar nie suikers nie, met asetaat plus etanol en/of waterstof as eindprodukte. [32]

  • Paleobacter carbinolcus, geïsoleerd van anoksiese modder, behoort dit tot die familie Desulfuromonadaceae. Hierdie bakteriese spesie groei deur fermentasie, sintrofiese waterstof/formiaat-oordrag, of elektronoordrag na swael uit kortketting-alkohole, waterstof of formiaat, maar dit oksideer nie asetaat nie. Daar is geen onlangse inligting oor suikerfermentasie of outotrofiese groei nie. Die volgorde-analise van genoom het die uitdrukking van c-tipe sitochrome en die gebruik van Fe (III) as 'n terminale acceptor getoon met die indirekte vermindering van elementêre swael wat as 'n pendeltuig vir elektronoordrag na Fe (III). Onlangse studie het gedink dat hierdie elektronoordrag twee periplasmiese tioredoksiene (Pcar_0426, Pcar_0427), 'n buitenste membraanproteïen (Pcar_0428) en 'n sitoplasmiese oksidoreduktase (Pcar_0429) behels wat deur die mees hoogs opgereguleerde gene gekodeer word. [32]

Klas Epsilonproteobakterieë Redigeer

Die klas Epsilonproteobacteria word in die NCBI -klassifikasie as deel van die filum Proteobacteria gelys, maar volgens GTDB -klassifikasie word dit erken as 'n nuwe filum met die naam Campylobacteriota [12] [13] . Dit bied baie swael-oksiderende bekende spesies aan, wat onlangs erken is dat dit elementêre swael kan verminder, en in sommige gevalle ook die pad verkies, tesame met waterstofoksidasie. [33] Hier is 'n lys van die spesies wat elementêre swael kan verminder. Die meganisme wat gebruik word om swael te verminder, is nog steeds onduidelik vir sommige van hierdie spesies. [9]

Tabel 3. Swaelverminderende bakterieë onder Epsiloproteobacteria/Campylobacteriota [1] [10] [9]
Spesies
Van hidrotermiese vents Caminibacter spp. (C. hydrogeniphilus, C. mediatlanticus, C. profundus)
Hydrogenimonas thermophila
Lebetimonas acidiphila
Nautilia spp. (N. abyssi, N. lithotrophica, N. nitratireducens, N. profundicola)
Nitratiruptor tergarcus
Sulfurimonas spp.
Sulfurospirillum sp. Am-N
Sulfurovum sp. NCB37-1
Thioreductor micantisoli
Van beespens Wolinella succinogenes

Wolinella Redigeer

Wolinella is 'n swaelverminderende genus van bakterieë en onvolledige oksideermiddel wat asetaat nie as elektronskenker kan gebruik nie. [1] Dit is in die openbaar slegs een spesie bekend, Wolinella succinogenens. [34]

  • Wolinella succinogenens is 'n bekende, nie-vent swael-verminderende bakterie wat in beespens voorkom, wat 'n [Ni-fe] hydrogenase gebruik om waterstof te oksideer en 'n enkele periplasmatiese polisulfiedreduktase (PsrABC) wat aan die binnemembraan gebind is om elementêre swael te verminder. [10] PsrA is verantwoordelik vir die vermindering van polisulfide na H2S, op 'n molibdopterien aktiewe plek, PsrB is 'n [FeS] elektronoordragproteïen en PsrC is 'n kinonbevattende membraanker. [35]
Sulfurospirillum Redigeer

Sulfurospirillum spesies is swaelverminderende bakterieë en onvolledige oksideermiddel wat H2 of óf formate as elektrondonor gebruik, maar nie asetaat nie. [1]

Sulfurovum Redigeer
  • Sulfurovum sp. NCB37-1 het die hipotese gekry waarin 'n polisulfiedreduktase (PsrABC) betrokke is by die vermindering van swael. [9] [36]
Sulfurimonas Redigeer

Sulfurimonas spesies is voorheen as chemolieto-outotrofe swael-oksiderende bakterieë (SOB) beskou, en daar was slegs genetiese bewyse wat 'n moontlike swaelverminderende metabolisme ondersteun, maar nou is bewys dat swaelvermindering in hierdie genus voorkom. Dit is ook afgelei die meganisme en die ensieme betrokke by hierdie proses, met behulp van Sulfurimonas sp. NW10 as verteenwoordiger. In die besonder is die teenwoordigheid van beide 'n sitoplasmiese en 'n periplasmiese polisulfiedreduktase opgespoor om siklooktaswael, wat die algemeenste vorm van elementêre swael in ventilasie -omgewings is, te verminder. [9]

  • Sulfurimonas sp. NW10 toon 'n ooruitdrukking van die geenklusters ( psr A 1 B 1 CDE B_<1>CDE> en psr A 2 B 2 B_<2>>) kodering vir die twee reduktase terwyl swael verminder word. Hierdie trosse is ook in ander gevind Sulfurimonas spesies geïsoleer van hidrotermiese vents, wat beteken dat swaelreduksie algemeen voorkom Sulfurimonas spp. [9]

Verdere genetiese ontleding het aan die lig gebring dat die polisulfiedreduktase van Sulfurimonas sp.NW10 deel minder as 40% ry -ooreenkoms met die van W.succinogenes .Dit beteken dat daar mettertyd 'n beduidende genetiese differensiasie tussen die twee bakterieë was, waarskynlik as gevolg van hul verskillende omgewings. Verder word die sitoplasmiese swaelreduksie uitgevoer deur Sulfurimonas sp. NW10 word deesdae as uniek beskou en is die enigste voorbeeld onder al die mesofiele swaelverminderende bakterieë. [9] Voor hierdie ontdekking was slegs twee hipertermofiele bakterieë bekend wat in staat was om sitoplasmiese swaelreduksie te doen, Aquifex aeolicus [37] en Thermovibrio ammonificans. [35]

Nautilia Redigeer

Nautilia spesies is anaërobiese, neutrofiele, termofiele swael-verminderende bakterieë, wat die eerste keer ontdek en geïsoleer is van 'n polychaete wurm wat diepsee hidrotermiese vents bewoon, Alvinella pompejana. Dit is baie kort, gramnegatiewe, beweeglike en staafvormige selle met 'n enkele poolvlag. [38] Hulle groei chemolito-outotrofies op molekulêre waterstof, elementêre swael en CO2. [39] Gebruik suikers, peptiede, organiese sure of alkohole word nie vereis nie beide in die afwesigheid en teenwoordigheid van swael. Hulle gebruik selde sulfiet en kolloïdale swael as elektronaanvaarders. Sulfaat, tiosulfaat, nitraat, fumaraat en yster word nie gebruik nie. Vier spesies is gevind: Nautilia lithotrophica, Nautilia profundicola, Nautilia nitratireducens en Nautilia abyssi. Die tipe spesie is Nautilia lithotrophica. [38]

  • Nautilia abyssi is gram-negatiewe swaelverminderende bakterieë, wat in anaërobiese toestande op groot dieptes leef (soos hidrotermiese uitlaat). Groeigebied is van 33° tot 65°C en pH optimum is 6,0-6,5. Selle het enkele polêre flagellum wat gebruik word vir beweging soortgelyk aan ander spesies van genus. Oor hul metabolisme gebruik hulle H2 as elektronskenker, elementêre swael as elektronaannemer en Co2 as koolstofbron. [40]
Caminibacter Redigeer
  • Caminibacter mediatlanticus is vir die eerste keer geïsoleer van 'n diepsee hidrotermiese opening op die Middel-Atlantiese Ridge. [41] Dit is 'n termofiele chemolieto-outotrofe, H2-oksiderende mariene bakterieë, wat nitraat of elementêre swael as elektronaanvaarders gebruik, wat ammoniak of waterstofsulfied produseer en dit kan nie suurstof, tiosulfaat, sulfiet, selenaat en arsenaat gebruik nie. Sy optimale groei is by 55 ° C, en dit blyk te wees geïnhibeer deur asetaat, formiaat, laktaat en peptoon. [41]

Aquificae Wysig

Aquificae filum bestaan ​​uit staafvormige, beweeglike selle. Sluit chemo-organotrofe in en sommige van hulle is in staat om elementêre swael te verminder. Groei is waargeneem tussen pH 6,0 en 8,0. [42]

Aquifex Redigeer

Aquifex is staafvormige, gramnegatiewe, nie-sporulerende selle met afgeronde ente. Wigvormige refraktiele gebiede in die selle word tydens groei gevorm. Tipe spesies: Aquifex pyrophilus. [42]

Desulfurobacterium Redigeer

Desulfurobacterium is staafvormige, Gram-negatiewe selle. Tipe spesies: Desulfurobacterium thermolithotrophum. [42]

Thermovibrio ammonificans Redigeer

Thermovibrio ammonificans [35] is 'n gram-negatiewe swaelverminderende bakterie wat in die diepsee hidrotermiese skoorsteen gevind word. Hy is 'n chemolieto -outotroof wat groei in die teenwoordigheid van H2 en CO2, en gebruik nitraat of elementêre swael as elektronaanvaarders met gepaardgaande vorming van onderskeidelik ammonium of waterstofsulfied. Tiosulfaat, sulfiet en suurstof word nie as elektronaanvaarders gebruik nie. Selle is kort stawe vorm en beweeglik danksy polêre flagellasie. Hul groeireekstemperatuur is van 60 °C tot 80 °C en pH 5-7. [43]

Termosulfidibacter spp. Redigeer

Termosulfidibacter is gram-negatiewe, anaërobiese, termofiele en neutrofiele bakterieë. Streng chemolithoautotrophic.The tipe spesie is Thermosulfidibacter takaii.

  • Thermosulfidibacter takaii a re beweeglike stawe met 'n polêre flagellum.Streng anaërobies. Groei vind plaas by 55–78 °C (optimum, 70 °C), pH 5.0–7.5 (optimum, pH 5.5–6.0). Hulle is swaelverminderaars. [44]

Firmicutes Redigeer

Firmicutes is meestal Gram-positiewe bakterieë met enkele Gram-negatiewe uitsonderings. [45]

Ammonifex Redigeer

Hierdie bakterieë is gram-negatief, uiters termofiel, streng anaërobies, fasulerende chemolieto-outotrofies. Tipe spesies: Ammonifex degensii. [46] [47]

Carboxydothermus Redigeer

  • Carboxydothermus pertinax verskil van ander lede van sy genus deur sy vermoë om chemolieto-outotrofies te groei met die vermindering van elementêre swael of tiosulfaat gekoppel aan CO-oksidasie.Die ander elektronaanvaarder is ystersitraat, amorf yster (III) oksied, 9,10-antrakinon 2,6-disulfonaat . Hydrogen is used as energy source and CO2 as carbon source. Cells are rod-shaped with peritrichous flagella and grow at 65 °C temperature. [48]

Chrysiogenetes Edit

Chrysiogenetes are Gram-negative bacteria, motile thanks to a single polar flagellum, curved, rod-shaped cells. They are mesophilic, exhibiting anaerobic respiration in which arsenate serves as the electron acceptor. Strictly anaerobic, these bacteria are grown at 25-30 °C. [49]

Desulfurispirillum spp. Redigeer

Desulfurispirillum species are gram-negative, motile spirillas, obligately anaerobic with respiratory metabolism. Use elemental sulfur and nitrate as electron acceptors, and short-chain fatty acids and hydrogen as electron donors. Alkaliphilic and slightly halophilic. [50]

  • Desulfurispirillum alkaliphilum[50] is obligate anaerobic and heterotrophic bacteria,motile by single bipolar flagella. It uses elemental sulfur, polysulfide, nitrate and fumarate as electron acceptors. The final products are sulfide and ammonium. Utilizes short-chain fatty acids and H2 as electron donor and carbon as source. It is moderate alkaliphilic with a pH range for growth between 8.0 and 10.2 and an optimum at pH 9.0 and slightly halophilic with a salt range from 0.1 to 2.5 M Na+. Mesophilic with a maximum temperature for growth at 45 and an optimum at 35 °C. [50]

Spirochaetes Edit

Spirochaetes are free-living, gram-negative, helical-shaped and motile bacteria, often protist or animal-associated. They are obligate and facultative anaerobes. [51] Among this phylum, two species are recognized as sulfur-reducing bacteria, Spirochaeta perfilievii en Spirochaeta smaragdinae.

  • Spirochaeta perfilievii are gram-negative, helical bacteria. Their size range varies from 10 to 200 μm .The shortest cells are those grown in axtremely anaerobic environments. They are mesophilic with a temperature range 4–32 °C (optimum at 28–30 °C). Grows at pH 6.5–8.5 (optimum pH 7.0–7.5). Obligate,moderate halophile. Under anaerobic conditions, sulfur and thiosulfate are reduced to sulfide. [52]
  • Spirochaeta smaragdinae are gram-negative, chemoorganotrophic, obligately anaerobic and halophilic bacteria. They are able to reduce sulfur to sulfide. Their temperature range is from 20-40 °C (optimum 37 °C), their pH range varies from 5.5 to 8.0 (optimum 7.0). [53]

Synergistetes Edit

Dethiosulfovibrio spp. Redigeer

Dethiosulfovibrio are a gram negative sulfur reducing bacteria that was isolated from "Thiodendron", bacterial sulfur mats obtained from different saline environments. Cells are curved or fibroid-like rods and motile thanks to flagella located on the concave side of the cells. The temperature range is from 15° to 40 °C and at pH values between 5±5 and 8±0. About their metabolism, they ferments proteins, peptides, some organic acids and amino acids like serine, histidine, lysine, arginine, cysteine and threonine. Only in the presence of sulfur or thiosulfate can use alanine, glutamate, isoleucine, leucine and valine, moreover the presence of sulfur or thiosulfate increases the cell yield and the growth rate.They are obligately anaerobic and slightly halophilic. In the presence of fermentable substrates they are able to reduce elemental sulfur and thiosulfate but not sulfate or sulfite to sulfide. Growth did not occur with H2 as electron donor and carbon dioxide or acetate as carbon sources in the presence of thiosulfate or elemental sulfur as electron acceptor. Unable to utilize carbohydrates, alcohols and some organic acids like acetate or succinate. Four species were found, Dethiosulfovibrio russensis, Dethiosulfovibrio marinus, Dethiosulfovibrio peptidovorans en Dethiosulfovibrio acidaminovorans [54]

Thermanaerovibrio spp. Redigeer

Thermophilic and neutrophilic Gram-negative bacteria. Motile thanks to lateral flagella, located on the concave side of the cell. Non-spore-forming. Multiplication occurs by binary fission. Strictly anaerobic with chemo-organotrophic growth on fermentable substrates or lithoheterotrophic growth with molecular hydrogen and elemental sulfur, reducing the sulfur to H2S. Inhabits the granular methanogenic sludge and neutral hot springs.The type species is Thermanaerovibrio acidaminovorans [55]

  • Thermanaerovibrio Velox is gram-negative bacteria that was isolated from a thermophilic cyanobacterial mat from caldera Uzon, Kamchatka, Russia. The reproduction occurs by binary-fission and they do not form spore. Growth temperature goes from 45° to 70°, and pH range from 4 to 8. [55]

Thermodesulfobacteria Edit

Thermodesulfobacteria are Gram- negative, rod-shaped cells, occur singly, in pairs, or in chains in young cultures. Do not form spores. Usually nonmotile, but motility might be observed in some species. Thermophilic, strictly anaerobic, chemoheterotrophs. [56]

Thermotogae Edit

Thermotoga spp. are gram-negative, rod-shaped, non-spore forming, hyperthermophilic microorganisms, given their name by the presence of a sheathlike envelope called “toga”. They are strictly anaerobes and fermenters, catabolizing sugars or starch and producing lactate, acetate, CO2, and H2 as products, [1] and can grow in a range temperature of 48-90 °C. [57] High levels of H2 inhibit their growth, and they share many genetic similarities with Archaea, caused by horizontal gene transfer [58] They are also able to perform anaerobic respiration using H2 as electron donor and usually Fe(III) as electron acceptor. Species belonging to the genus Thermotoga were found in terrestrial hot springs and marine hydrothermal vents. The species able to reduce sulfur don't show an alteration of growth yield and stoichiometry of organic products, and no ATP production occurs. Furthermore, tolleration to H2 increases during sulfur reduction, thus they produce H2S to overcome growth inhibition. [14] The genome of Thermotoga spp. is widely used as a model for studying adaptation to high temperatures, microbial evolution and biotechnological opportunities, such as biohydrogen production and biocatalysis. [59]

  • Thermotoga maritima is the type species for the genus Thermotoga, growth is observed between 55 °C and 90 °C, the optimum is at 80 °C. Each cell presents a unique sheath- like structure and monotrichous flagellum. It was firstly isolated from a geothermally heated, shallow marine sediment at Vulcano, in Italy. [60]
  • Thermotoga neapolitana is the second species isolated belonging to the genus Thermotoga. It was firstly found in a submarine thermal vent at Lucrino, near Naples, Italy, and has its optimum growth at 77 °C [61][62]

Sulfur-reducing bacteria are mostly mesophilic and thermophilic. [10] Growth has been observed between a temperature range 37-95 °C, however the optimum is different depending on the species (i.e. Thermotoga neapolitana optimum 77 °C, Nautilia lithotrophica optimum 53 °C). [61] [38] [62] They have been reported in many different environments, such as anoxic marine sediments, brackish and freshwater sediments, anoxic muds, bovine rumen, hot waters from solfataras and volcanic areas. [10] Many of these bacteria are used to be found in hot vents, where elemental sulfur is an abundant sulfur species. This happens due to volcanic activities, in which hot vapours and elemental sulfur are released together through the fractures of Earth's crust. [63] The ability of using zero valence sulfur as both an electron donor or acceptor, allows Sulfurimonas spp. to spread widely among different habitats, from highly reducing to more oxidizing deep-sea environments. [9] In some communities found in hydrothermal vents, their proliferation is enhanced thanks to the reactions carried out by thermophilic photo- or chemoautotrophs, in which there is simultaneously production of elemental sulfur and organic matter, respectively electron acceptor and energy source for sulfur-reducing bacteria. [63] Sulfur reducers of hydrothermal vents can be free-living organisms, or endosymbionts of animals such as shrimps and tube worms. [40]

Symbiosis Edit

Thiodendron latens is a symbiotic association of aerotolerant spirochaetes and anaerobic sulfidogenes. The spirochaete species are the main structural and functional component of these mats and they may accumulate elemental sulfur in the intracellular space. This association of micro-organisms inhabits sulfide-rich habitats, where the chemical oxidation of sulfide by oxygen, manganese or ferric iron or by the activity of sulfide-oxidizing bacteria results in the formation of thiosulfate or elemental sulfur. The partly oxidized sulfur compounds can be either completely oxidized to sulfate by sulfur-oxidizing bacteria, if enough oxygen is present, or reduced to sulfide by sulfidogenic bacteria. In such places oxygen limitation is frequent, as indicated by micro-profile measurements from such habitats. This relationship may rappresent an effective shortcut in the sulfur cycle. [54]

Synthophy Edit

Desulfuromonas acetooxidans is able to grow in cocultures with green sulfur bacteria such as Chlorobium (vibrioforme en phaeovibroides). The electron donor for the sulfur-reducing bacterium is acetate, coupled with elemental sulfur reduction to sulfide. The green sulfur bacterium produces H2 re-oxidizing the H2S previously produced, in presence of light. During these cocultures experiments no elemental sulfur appears in the medium because it’s immediately reduced. [64]

Sulfur cycle Edit

The sulfur cycle is one of the major biogeochemical processes. [65] The majority of sulfur on Earth is present in sediments and rocks, but its quantity in the oceans represent the primary reservoir of sulfate of the entire biosphere. Human activities such as burning fossil fuels, also contribute to the cycle by entering a significant amount of sulfur dioxide in the atmosphere. [66] The earliest life forms on Earth were sustained by sulfur metabolism, and the enormous diversity of present microorganisms is still supported by the sulfur cycle. [66] It also interacts with numerous biogeochemical cycles of other elements such as carbon, oxygen, nitrogen and iron. [67] [66] Sulfur has diverse oxidation states ranging from +6 to −2, which permit to sulfur compounds to be used as electron donors and electron acceptors in numerous microbial metabolisms, which transform organic and inorganic sulfur compounds, contributing to physical,biological and chemical components of the biosphere. [2] [67]

The sulfur cycle follows several linked pathways.

Under anaerobic conditions, sulfate is reduced to sulfide by sulfate reducing bacteria, such as Desulfovibrio en Desulfobacter.

Under aerobic conditions, sulfide is oxidized to sulfur and then sulfate by sulfur oxidizing bacteria, such as Thiobacillus, Beggiatoa en vele ander. Under anaerobic conditions, sulfide can be oxidized to sulfur and then sulfate by Purple and Green sulfur bacteria.

Sulfur can also be oxidized to sulfuric acid by chemolithotrophic bacteria, such as Thiobacillus en Acidithiobacillus

Some bacteria are capable to reduce sulfur to sulfide enacting a sort of anaerobic respiration. This process can be carried out by both sulfate reducing bacteria and sulfur reducing bacteria. Although they thrive in the same habitats, sulfur reducing bacteria are incapable of sulfate reduction. Bacteria like Desulfuromonas acetoxidans are able to reduce sulfur at the cost of acetate. Some iron reducing bacteria reduce sulfur to generate ATP. [68]

These are the main inorganic processes involved in the sulfur cycle but organic compounds can contribute as well to the cycle. The most abundant in nature is dimethyl sulfide (CH3—S—CH3) produced by the degradation of dimethyl sulfoniopropionate. Many other organic S compounds affect the global sulfur cycle, including methanethiol , dimethyl disulfide, en carbon disulfide. [66]

Microorganisms that have sulfur-based metabolism represent a great opportunity for industrial processes, in particular the ones that execute sulfidogenesis (production of sulfide). For example, these type of bacteria can be used in to generate hydrogen sulfide in order to obtain the selective precipitation and recovery of heavy metals in metallurgical and mining industries. [2]

Flue gases treatment Edit

According to an innovative chinese research, the SCDD process used to desulfurize flue gases can be lowered in costs and environmental impact, using biological reduction of elemental sulfur to H2S, which represents the reducing agent in this process. The electron donors would be organics from wastewater, such as acetate and glucose. The SCDD process revisited in this way would take three steps at determinate conditions of pH, temperature and reagents concentration. The first in which biological sulfur reduction occurs, the second through which dissolved H2S in wastewaters is stripped into hydrogen sulfide gas, and the third consists in the treatment of flue gases, removing over 90% of SO2 and NO, according to this study. Furthermore, the 88% of the sulfur input would be recovered as octasulfur and then reutilized, representing both a chemical-saving and a profitable solution. [69]

Treatment of arsenic-contaminated waters Edit

Sulfur reducing bacteria are used to remove Arsenite from the arsenic-contaminated waters, like acid mine drainage (AMD), metallurgy industry effluents, soils, surface and ground waters. The sulfidogenic process driven by sulfur reducing bacteria (Desulfurella) take place under acid condition and produce sulfide with which arsenite precipitates. Microbial sulfur reduction also produces protons that lower the pH in arsenic-contaminated water and prevent the formation of thioarsenite by-production with sulfide. [70]

Treatment of mercury-contaminated waters Edit

Wastewater deriving from industries that work on chloralkali and battery production, contains high levels of mercury ions, threatening aquatic ecosystems. [71] Recent studies demonstrate that sulfidogenic process by sulfur reducing bacteria can be a good technology in the treatment of mercury-contaminate waters. [72]


Patterns of sulfur isotope fractionation during microbial sulfate reduction

Studies of microbial sulfate reduction have suggested that the magnitude of sulfur isotope fractionation varies with sulfate concentration. Small apparent sulfur isotope fractionations preserved in Archean rocks have been interpreted as suggesting Archean sulfate concentrations of <200 μ m , while larger fractionations thereafter have been interpreted to require higher concentrations. In this work, we demonstrate that fractionation imposed by sulfate reduction can be a function of concentration over a millimolar range, but that nature of this relationship depends on the organism studied. Two sulfate-reducing bacteria grown in continuous culture with sulfate concentrations ranging from 0.1 to 6 m m showed markedly different relationships between sulfate concentration and isotope fractionation. Desulfovibrio vulgaris str. Hildenborough showed a large and relatively constant isotope fractionation ( 34 εSO4-H2S ≅ 25‰), while fractionation by Desulfovibrio alaskensis G20 strongly correlated with sulfate concentration over the same range. Both data sets can be modeled as Michaelis–Menten (MM)-type relationships but with very different MM constants, suggesting that the fractionations imposed by these organisms are highly dependent on strain-specific factors. These data reveal complexity in the sulfate concentration–fractionation relationship. Fractionation during MSR relates to sulfate concentration but also to strain-specific physiological parameters such as the affinity for sulfate and electron donors. Previous studies have suggested that the sulfate concentration–fractionation relationship is best described with a MM fit. We present a simple model in which the MM fit with sulfate concentration and hyperbolic fit with growth rate emerge from simple physiological assumptions. As both environmental and biological factors influence the fractionation recorded in geological samples, understanding their relationship is critical to interpreting the sulfur isotope record. As the uptake machinery for both sulfate and electrons has been subject to selective pressure over Earth history, its evolution may complicate efforts to uniquely reconstruct ambient sulfate concentrations from a single sulfur isotopic composition.

Lêernaam Beskrywing
gbi12149-sup-0001-Supinfo.docxWord document, 154.3 KB Supplemental Materials and Methods
gbi12149-sup-0002-FileS1.xlsbMS Excel, 83.8 KB Data S1. D. vulgaris growth data
gbi12149-sup-0003-FileS2.xlsxMS Excel, 141.3 KB Data S2. D. alaskensis growth data

Neem asseblief kennis: Die uitgewer is nie verantwoordelik vir die inhoud of funksionaliteit van enige ondersteunende inligting wat deur die skrywers verskaf word nie. Enige navrae (behalwe ontbrekende inhoud) moet aan die ooreenstemmende outeur vir die artikel gerig word.


Earth System Science

James T. Staley , Gordon H. Orians , in International Geophysics , 2000

3.6.4 The Sulfur Cycle

Reduced sulfur compounds serve as hydrogen donors for anoxygenic photosynthetic bacteria such as the green and purple sulfur bacteria and some cyanobacteria. In contrast, chemoautotrophic sulfur bacteria obtain energy from the oxidation of reduced sulfur compounds including hydrogen sulfide, sulfur, and thiosulfate. As with the nitrifying bacteria, these bacteria are primarily aerobic and use carbon dioxide as their source of carbon. The ultimate product of their metabolism is sulfuric acid. These bacteria are responsible for the production of acid mine waters in areas where strip mining has exposed pyrite minerals to rainfall and oxygen. Some of these bacteria can grow at pH values as low as 1.0 pH values of 3.0 and 4.0 are common in runoff streams from mining areas. Fish cannot live in these waters and most plants cannot grow in such highly acidic soils.

Dissimilatory sulfate reducers such as Desulfovibrio derive their energy from the anaerobic oxidation of organic compounds such as lactic acid and acetic acid. Sulfate is reduced and large amounts of hydrogen sulfide are generated in this process. The black sediments of aquatic habitats that smell of sulfide are due to the activities of these bacteria. The black coloration is caused by the formation of metal sulfides, primarily iron sulfide. These bacteria are especially important in marine habitats because of the high concentrations of sulfate that exists there.

Dimethylsulfide (DMS) is the major volatile sulfur compound of biogenic origin emitted from the oceans into the atmosphere. It is estimated that the annual global sea-to-air flux is 15–40 million metric tons of sulfur per year. DMS is produced by the enzymatic cleavage of dimethylpropiothetin (DMPT). The function of DMPT in these algae is uncertain, but there is strong evidence that it may function as a very effective osmoregulator ( Andreae and Bernard, 1984 Vairavamurthy et al., 1985). The dipolar ionic nature of DMPT gives the molecule a very low membrane permeability. The osmotic role of DMPT is also suggested by the fact that most freshwater algae produce little or no DMS, although cyanobacteria do. The dimethylsulfide produced by marine algae reacts in the atmosphere to form sulfuric acid as well as ammonium sulfate, ammonium bisulfate, and methane sulfonic acid, all of which have low vapor pressures in the atmosphere and can condense to form aerosol particles. These particles can affect climate by changing the reflective properties of the marine atmosphere and by providing particles on which cloud droplets can nucleate. (See Chapters 7 and 17 for more details.)


5.9C: Sulfate and Sulfur Reduction - Biology

Alle artikels wat deur MDPI gepubliseer word, word onmiddellik wêreldwyd beskikbaar gestel onder 'n ooptoeganglisensie. Geen spesiale toestemming is nodig om die hele of 'n gedeelte van die artikel wat deur MDPI gepubliseer is, te hergebruik nie, insluitend syfers en tabelle. Vir artikels wat onder 'n oop toegang Creative Commons CC -lisensie gepubliseer word, mag enige deel van die artikel sonder toestemming hergebruik word, mits die oorspronklike artikel duidelik aangehaal word.

Feature Papers verteenwoordig die mees gevorderde navorsing met 'n groot potensiaal vir 'n groot impak in die veld. Speelvraestelle word op individuele uitnodiging of aanbeveling deur die wetenskaplike redakteurs ingedien en ondergaan ewekniebeoordeling voor publikasie.

Die artikel kan óf 'n oorspronklike navorsingsartikel wees, 'n aansienlike nuwe navorsingsstudie wat dikwels verskeie tegnieke of benaderings behels, óf 'n omvattende oorsigstuk met bondige en presiese opdaterings oor die nuutste vordering op die gebied wat stelselmatig die opwindendste vooruitgang in wetenskaplike stelsels hersien. letterkunde. Hierdie tipe papier bied 'n vooruitsig op toekomstige navorsingsrigtings of moontlike toepassings.

Editor's Choice -artikels is gebaseer op aanbevelings deur die wetenskaplike redakteurs van MDPI -tydskrifte van regoor die wêreld. Redakteurs kies 'n klein aantal artikels wat onlangs in die joernaal gepubliseer is wat hulle glo veral interessant sal wees vir skrywers, of belangrik sal wees in hierdie veld. Die doel is om 'n oorsig te gee van enkele van die opwindendste werk wat in die verskillende navorsingsgebiede van die tydskrif gepubliseer is.


Verwysings

Akcil, A., and Koldas, S. (2006). Acid mine drainage (AMD): causes, treatment and case studies. J. Skoon. Prod. 14, 1139�. doi: 10.1016/j.jclepro.2004.09.006

Anawar, H. M. (2015). Sustainable rehabilitation of mining waste and acid mine drainage using geochemistry, mine type, mineralogy, texture, ore extraction and climate knowledge. J. Omgewing. Bestuur. 158, 111�. doi: 10.1016/j.jenvman.2015.04.045

Ayangbenro, A. S., and Babalola, O. O. (2017). A new strategy for heavy metal polluted environments: a review of microbial biosorbents. Int. J. Omgewing. Res. Openbare gesondheid 14:94. doi: 10.3390/ijerph14010094

Bai, H., Kang, Y., Quan, H., Han, Y., Sun, J., and Feng, Y. (2013). Treatment of acid mine drainage by sulfate reducing bacteria with iron in bench scale runs. Bioresour. Tegn. 128, 818�. doi: 10.1016/j.biortech.2012.10.070

Barton, L. L., and Fauque, G. D. (2009). Biochemistry, physiology and biotechnology of sulfate-reducing bacteria. Adv. Appl. Mikrobiol. 68, 41�. doi: 10.1016/S0065-2164(09)01202-7

Bratty, M., Lawrence, R., Kratochvil, D., Marchant, P., and Louis, M. O. (2006). 𠇊pplications of biological H2S production from elemental sulfur in the treatment of heavy metal pollution including acid rock drainage,” in Proceedings of the 7th International Symposium of Acid Rock Drainage (ICARD), Louis: MO, 271�.

Brenner, K., You, L., and Arnold, F. H. (2008). Engineering microbial consortia: a new frontier in synthetic biology. Tendense Biotechnol. 26, 483�. doi: 10.1016/j.tibtech.2008.05.004

Brune, K. D., and Bayer, T. S. (2012). Engineering microbial consortia to enhance biomining and bioremediation. Voorkant. Mikrobiol. 3:203. doi: 10.3389/fmicb.2012.00203

Bryan, C. G., Hallberg, K. B., and Johnson, D. B. (2006). Mobilisation of metals in mineral tailings at the abandoned São Domingos copper mine (Portugal) by indigenous acidophilic bacteria. Hydrometallurgy 83, 184�. doi: 10.1016/j.hydromet.2006.03.023

Chakravarty, R., and Banerjee, P. C. (2008). Morphological changes in an acidophilic bacterium induced by heavy metals. Ekstremofiele 12, 279�. doi: 10.1007/s00792-007-0128-4

Cohen, R. R. H. (2006). Use of microbes for cost reduction of metal removal from metals and mining industry waste streams. J. Skoon. Prod. 14, 1146�. doi: 10.1016/j.jclepro.2004.10.009

Davies, T., and Mundalamo, H. (2010). Environmental health impacts of dispersed mineralisation in South Africa. J. Afr. Aarde Wetenskap. 58, 652�. doi: 10.1016/j.jafrearsci.2010.08.009

Dold, B. (2014). Evolution of acid mine drainage formation in sulphidic mine tailings. Minerale 4, 621�. doi: 10.1007/s00792-010-0324-5

Dunbar, W. S. (2017). Biotechnology and the mine of tomorrow. Tendense Biotechnol. 35, 79�. doi: 10.1016/j.tibtech.2016.07.004

Fashola, M., Ngole-Jeme, V., and Babalola, O. (2016). Heavy metal pollution from gold mines: environmental effects and bacterial strategies for resistance. Int. J. Omgewing. Res. Openbare gesondheid 13:1047. doi: 10.3390/ijerph13111047

Franks, D. M., Boger, D. V., Côte, C. M., and Mulligan, D. R. (2011). Sustainable development principles for the disposal of mining and mineral processing wastes. Hulpbron. Beleid 36, 114�. doi: 10.1016/j.resourpol.2010.12.001

Hallberg, K. (2010). New perspectives in acid mine drainage microbiology. Hydrometallurgy 104, 448�. doi: 10.1016/j.hydromet.2009.12.013

Hays, S. G., Patrick, W. G., Ziesack, M., Oxman, N., and Silver, P. A. (2015). Better together: engineering and application of microbial symbioses. Curr. Mening. Biotegnologie. 36, 40�. doi: 10.1016/j.copbio.2015.08.008

Hilson, G., and Murck, B. (2001). Progress toward pollution prevention and waste minimization in the North American gold mining industry. J. Skoon. Prod. 9, 405�. doi: 10.1016/S0959-6526(00)00083-4

Hudson-Edwards, K. A., Jamieson, H. E., and Lottermoser, B. G. (2011). Mine wastes: past, present, future. Elemente 7, 375�. doi: 10.2113/gselements.7.6.375

Hussain, A., Hasan, A., Javid, A., and Qazi, J. I. (2016). Exploited application of sulfate-reducing bacteria for concomitant treatment of metallic and non-metallic wastes: a mini review. 3 Biotech 6:119. doi: 10.1007/s13205-016-0437-3

Jain, R. K., Cui, Z. C., and Domen, J. K. (2016). 𠇎nvironmental impacts of mining”, in Environmental Impact of Mining and Mineral Processing. Boston: Butterworth-Heinemann, 53�. doi: 10.1016/B978-0-12-804040-9.00004-8

Jerez, C. A. (2017). Biomining of metals: how to access and exploit natural resource sustainably. Mikrob. Biotegnologie. 10, 1191�. doi: 10.1111/1751-7915.12792

Johnson, D. B. (2012). Geomicrobiology of extremely acidic subsurface environments. FEMS Microbiol. Ecol. 81, 2�. doi: 10.1111/j.1574-6941.2011.01293.x

Johnson, D. B., and Hallberg, K. B. (2005). Acid mine drainage remediation options: a review. Wetenskaplike. Totale omgewing. 338, 3�. doi: 10.1016/j.scitotenv.2004.09.002

Johnson, D. B., and Hallberg, K. B. (2009). Carbon, iron and sulfur metabolism in acidophilic micro-organisms. Adv. Mikrob. Fisiol. 54, 201�. doi: 10.1016/S0065-2911(08)00003-9

Kaksonen, A., and Puhakka, J. (2007). Sulfate reduction based bioprocesses for the treatment of acid mine drainage and the recovery of metals. Eng. Life Sci. 7, 541�. doi: 10.1002/elsc.200720216

Kefeni, K. K., Msagati, T. A. M., and Mamba, B. B. (2017). Acid mine drainage: prevention, treatment options, and resource recovery: a review. J. Skoon. Prod. 151, 475�. doi: 10.1016/j.jclepro.2017.03.082

Keller, L., and Surette, M. G. (2006). Communication in bacteria: an ecological and evolutionary perspective. Nat. Ds Microbiol. 4, 249�. doi: 10.1038/nrmicro1383

Kieu, H. T., Müller, E., and Horn, H. (2011). Heavy metal removal in anaerobic semi-continuous stirred tank reactors by a consortium of sulfate-reducing bacteria. Water Res. 45, 3863�. doi: 10.1016/j.watres.2011.04.043

Kousi, P., Remoundaki, E., Hatzikioseyian, A., and Tsezos, M. (2015). “Sulphate-reducing bioreactors: current practices and perspectives”, in Proceedings of the IWA Balkan Young Water Professionals 2015 (Thessaloniki: International Water Association), 409�.

Kuyucak, N. (2002). Role of microorganisms in mining: generation of acid rock drainage and its mitigation and treatment. EUR. J. Mineral Proc. Omgewing. Prot. 2, 179�.

Latorre, M., Cortés, M. P., Travisany, D., Di Genova, A., Budinich, M., Reyes-Jara, A., et al. (2016). The bioleaching potential of a bacterial consortium. Bioresour. Tegn. 218, 659�. doi: 10.1016/j.biortech.2016.07.012

Lin, C. C., and Lin, H. L. (2005). Remediation of soil contaminated with the heavy metal (Cd2+). J. Hazard. Mater. 122, 7�. doi: 10.1016/j.jhazmat.2005.02.017

Littlejohn, P., Kratochvil, D., and Consigny, A. (2015). Using Novel Technology for Residue Management and Sustainable Mine Closure. Vancouver, Can: Mine Closure, 1�.

Lorenzo, V. (2017). Synthetic microbiology: from analogy to methodology. Microbial. Biotegnologie. 10, 1264�. doi: 10.1111/1751-7915.12786

Martins, M., Santos, E. S., Faleiro, M. L., Chaves, S., Tenreiro, R., Barros, R. J., et al. (2011). Performance and bacterial community shifts during bioremediation of acid mine drainage from two Portuguese mines. Int. Biodeterior. Biodegradation 65, 972�. doi: 10.1016/j.ibiod.2011.07.006

McDougald, D., Rice, S. A., Barraud, N., Steinberg, P. D., and Kjelleberg, S. (2012). Should we stay or should we go: mechanisms and ecological consequences for biofilm dispersal. Nat. Ds Microbiol. 10, 39�. doi: 10.1038/nrmicro2695

Mendez, M. O., and Maier, R. M. (2008). Phytoremediation of mine tailings in temperate and arid environments. Rev. Environ. Wetenskaplike. Biotegnologie. 7, 47�. doi: 10.1007/s11157-007-9125-4

Méndez-Garc໚, C., Pelพz, A. I., Mesa, V., Sánchez, J., Golyshina, O. V., and Ferrer, M. (2015). Microbial diversity and metabolic networks in acid mine drainage habitats. Voorkant. Mikrobiol. 6:475. doi: 10.3389/fmicb.2015.00475

Mukhopadhyay, S., and Maiti, S. K. (2010). Phytoremediation of metal mine waste. Appl. Ecol. Omgewing. Res. 8, 207�.

Muyzer, G., and Stams, A. J. (2008). The ecology and biotechnology of sulphate-reducing bacteria. Nat. Ds Microbiol. 6, 441�. doi: 10.1038/nrmicro1892

Pérez-López, R., Nieto, J. M., and De Almodóvar, G. R. (2007). Utilization of fly ash to improve the quality of the acid mine drainage generated by oxidation of a sulphide-rich mining waste: column experiments. Chemosfeer 67, 1637�. doi: 10.1016/j.chemosphere.2006.10.009

Plugge, C. M., Zhang, W., Scholten, J. C., and Stams, A. J. (2011). Metabolic flexibility of sulfate-reducing bacteria. Voorkant. Mikrobiol. 2:81. doi: 10.3389/fmicb.2011.00081

Poljsak, B., P༼si, I., and Pesti, M. (2011). “Interference of chromium with cellular functions,” in Cellular Effects of Heavy Metals, red. G. Bánfalvi (Berlin: Springer Science+Business Media B.V), 59�. doi: 10.1007/978-94-007-0428-2_3

Rohwerder, T., and Sand, W. (2003). The sulfane sulfur of persulfides is the actual substrate of the sulfur-oxidizing enzymes from Acidithiobacillus and Acidiphilium spp. Microbiology 149, 1699�. doi: 10.1099/mic.0.26212-0

Sahinkaya, E., Yurtsever, A., Toker, Y., Elcik, H., Cakmaci, M., and Kaksonen, A. H. (2015). Biotreatment of As-containing simulated acid mine drainage using laboratory scale sulfate reducing upflow anaerobic sludge blanket reactor. Minerals Eng. 75, 133�. doi: 10.1016/j.mineng.2014.08.012

Sahoo, P. K., Bhattacharyya, P., Tripathy, S., Equeenuddin, S. M., and Panigrahi, M. (2010). Influence of different forms of acidities on soil microbiological properties and enzyme activities at an acid mine drainage contaminated site. J. Hazard. Mater. 179, 966�. doi: 10.1016/j.jhazmat.2010.03.099

Sánchez-Andrea, I., Sanz, J. L., Bijmans, M. F., and Stams, A. J. (2014). Sulfate reduction at low pH to remediate acid mine drainage. J. Hazard. Mater. 269, 98�. doi: 10.1016/j.jhazmat.2013.12.032

Sánchez-Andrea, I., Stams, A. J., Hedrich, S., ᑺncucheo, I., and Johnson, D. B. (2015). Desulfosporosinus acididurans sp. nov.: an acidophilic sulfate-reducing bacterium isolated from acidic sediments. Ekstremofiele 19, 39�. doi: 10.1007/s00792-014-0701-6

Schippers, A., Breuker, A., Blazejak, A., Bosecker, K., Kock, D., and Wright, T. (2010). The biogeochemistry and microbiology of sulfidic mine waste and bioleaching dumps and heaps, and novel Fe (II)-oxidizing bacteria. Hydrometallurgy 104, 342�. doi: 10.1016/j.hydromet.2010.01.012

Sen, A., and Johnson, B. (1999). Acidophilic sulphate-reducing bacteria: candidates for bioremediation of acid mine drainage. Process Metallurgy 9, 709�. doi: 10.1016/S1572-4409(99)80073-X

Sheoran, A., Sheoran, V., and Choudhary, R. (2010). Bioremediation of acid-rock drainage by sulphate-reducing prokaryotes: a review. Minerals Eng. 23, 1073�. doi: 10.1016/j.mineng.2010.07.001

Tripathi, N., Singh, R. S., and Hills, C. D. (2016). Reclamation of Mine-Impacted Land for Ecosystem Recovery. Chichester: John Wiley & Sons. doi: 10.1002/9781119057925

Valentín-Vargas, A., Root, R. A., Neilson, J. W., Chorover, J., and Maier, R. M. (2014). Environmental factors influencing the structural dynamics of soil microbial communities during assisted phytostabilization of acid-generating mine tailings: a mesocosm experiment. Wetenskaplike. Totale omgewing. 500, 314�. doi: 10.1016/j.scitotenv.2014.08.107

Verstraete, W., and De Vrieze, J. (2017). Microbial technology with major potentials for the urgent environmental needs of the next decades. Microbial. Biotegnologie. 10, 988�. doi: 10.1111/1751-7915.12779

Wysocki, R., and Tamás, M. J. (2011). “Saccharomyces cerevisiae as a model organism for elucidating arsenic tolerance mechanisms,” in Cellular Effects of Heavy Metals, red. G. Bánfalvi (Berlin: Springer Science+Business Media B.V), 87�. doi: 10.1007/978-94-007-0428-2_4

Zhang, M., and Wang, H. (2014). Organic wastes as carbon sources to promote sulfate reducing bacterial activity for biological remediation of acid mine drainage. Minerals Eng. 69, 81�. doi: 10.1016/j.mineng.2014.07.010

Zhang, M., and Wang, H. (2016). Preparation of immobilized sulfate reducing bacteria (SRB) granules for effective bioremediation of acid mine drainage and bacterial community analysis. Minerals Eng. 92, 63�. doi: 10.1016/j.mineng.2016.02.008

Zhou, H.-B., Zeng, W.-M., Yang, Z.-F., Xie, Y.-J., and Qiu, G.-Z. (2009). Bioleaching of chalcopyrite concentrate by a moderately thermophilic culture in a stirred tank reactor. Bioresour. Tegn. 100, 515�. doi: 10.1016/j.biortech.2008.06.033

Zhou, J., He, Q., Hemme, C. L., Mukhopadhyay, A., Hillesland, K., Zhou, A., et al. (2011). How sulphate-reducing microorganisms cope with stress: lessons from systems biology. Nat. Ds Microbiol. 9, 452�. doi: 10.1038/nrmicro2575

Keywords : bioleaching, heavy metals, microorganism, mine wastes, mining, tailings

Citation: Ayangbenro AS, Olanrewaju OS and Babalola OO (2018) Sulfate-Reducing Bacteria as an Effective Tool for Sustainable Acid Mine Bioremediation. Voorkant. Mikrobiol. 9:1986. doi: 10.3389/fmicb.2018.01986

Received: 12 March 2018 Accepted: 07 August 2018
Published: 22 August 2018.

Rajesh K. Sani, South Dakota School of Mines and Technology, United States

Sema Sevinc Sengor, Southern Methodist University, United States
Venkataramana Gadhamshetty, South Dakota School of Mines and Technology, United States

Copyright © 2018 Ayangbenro, Olanrewaju and Babalola. Hierdie is 'n ooptoegang-artikel wat onder die bepalings van die Creative Commons Attribution License (CC BY) versprei word. Die gebruik, verspreiding of reproduksie in ander forums word toegelaat, mits die oorspronklike outeur (s) en die eienaar (s) van die outeursreg gekrediteer word en dat die oorspronklike publikasie in hierdie tydskrif aangehaal word, in ooreenstemming met aanvaarde akademiese praktyk. Geen gebruik, verspreiding of reproduksie word toegelaat wat nie aan hierdie bepalings voldoen nie.