Halo(natrono)archaea from hypersaline lakes can utilize sulfoxides other than DMSO as electron acceptors for anaerobic respiration

Sulfate reducing bacteria, capable to reductive transformation of different nature pollutants, used in biotechnologies of purification of sewage, contaminated by carbon, sulfur, nitrogen and metal compounds. H2S formed by them sediment metals to form of insoluble sulfides. Number of metals can be used by these microorganisms as electron acceptors during anaerobic respiration. Because under the influence of metal compounds observed slowing of bacteria metabolism, selection isolated from technologically modified ecotops resistant to pollutions strains is important task to create a new biotechnologies of purification. That’s why the purpose of this work was to study the influence of potassium dichromate, present in medium, on reduction of sulfate and nitrate ions by sulfate reducing bacteria Desulfovibrio desulfuricans IMV K-6, Desulfovibrio sp. Yav-6 and Desulfovibrio sp. Yav-8, isolated from Yavorivske Lake, to estimate the efficiency of possible usage of these bacteria in technologies of complex purification of environment from dangerous pollutants. Bacteria were cultivated in modified Kravtsov-Sorokin medium without SO42- and FeCl2×4H2O for 10 days. To study the influence of K2Cr2O7 on usage by bacteria SO42- or NO3- cells were seeded to media with Na2SO4×10H2O or NaNO3 and K2Cr2O7 at concentrations of 1.74 mM for total content of electron acceptors in medium 3.47 mM (concentration of SO42- in medium of standard composition). Cells were also seeded to media with 3.47 mM Na2SO4×10H2O, NaNO3 or K2Cr2O7 to investigate their growth in media with SO42-, NO3- or Cr2O72- as sole electron acceptor (control). Biomass was determined by turbidymetric method, content of sulfate, nitrate, dichromate, chromium (III) ions, hydrogen sulfide or ammonia ions in cultural liquid – by spectrophotometric method. It was found that K2Cr2O7 inhibits growth (2.2 and 1.3 times) and level of reduction by bacteria sulfate or nitrate ions (4.2 and 3.0 times, respectively) at simultaneous addition into cultivation medium of 1.74 mM SO42- or NO3- and 1.74 mM Cr2O72-, compared with growth and level of reduction of sulfate or nitrate ions in medium only with SO42- or NO3- as sole electron acceptor. Revealed that during cultivation of bacteria in presence of equimolar amount of SO42- or NO3- and Cr2O72-, last used by bacteria faster, content of Cr3+ during whole period of bacteria cultivation exceeded content H2S or NH4+. K2Cr2O7 in medium has most negative influence on dissimilatory reduction by bacteria SO42- than NO3-, since level of nitrate ions reduction by cells in medium with NO3- and Cr2O72- was a half times higher than level of sulfate ions reduction by it in medium with SO42- and Cr2O72-. The ability of bacteria Desulfovibrio sp. to priority reduction of Cr2O72- and after their exhaustion − NO3- and SO42- in the processes of anaerobic respiration can be used in technologies of complex purification of environment from toxic compounds.

Download Full-text

Sulfonates: novel electron acceptors in anaerobic respiration

Archives of Microbiology ◽

10.1007/s002030050376 ◽

1996 ◽

Vol 166 (3) ◽

pp. 204-210 ◽

Cited By ~ 52

Author(s):

Thomas J. Lie ◽

Thomas Pitta ◽

E. R. Leadbetter ◽

Walter Godchaux III. ◽

Jared R. Leadbetter

Keyword(s):

Anaerobic Respiration ◽

Electron Acceptors

Download Full-text

Role for Outer Membrane Cytochromes OmcA and OmcB of Shewanella putrefaciens MR-1 in Reduction of Manganese Dioxide

Applied and Environmental Microbiology ◽

10.1128/aem.67.1.260-269.2001 ◽

2001 ◽

Vol 67 (1) ◽

pp. 260-269 ◽

Cited By ~ 175

Author(s):

Judith M. Myers ◽

Charles R. Myers

Keyword(s):

Outer Membrane ◽

Anaerobic Respiration ◽

Shewanella Putrefaciens ◽

Gene Replacement ◽

Electron Acceptors ◽

Ferric Citrate ◽

Disulfonic Acid ◽

Pcr Analysis ◽

Western Blots ◽

Reverse Transcription Pcr

ABSTRACT Shewanella putrefaciens MR-1 can use a wide variety of terminal electron acceptors for anaerobic respiration, including certain insoluble manganese and iron oxides. To examine whether the outer membrane (OM) cytochromes of MR-1 play a role in Mn(IV) and Fe(III) reduction, mutants lacking the OM cytochrome OmcA or OmcB were isolated by gene replacement. Southern blotting and PCR confirmed replacement of the omcA and omcB genes, respectively, and reverse transcription-PCR analysis demonstrated loss of the respective mRNAs, whereas mRNAs for upstream and downstream genes were retained. The omcA mutant (OMCA1) resembled MR-1 in its growth on trimethylamine N-oxide (TMAO), dimethyl sulfoxide, nitrate, fumarate, thiosulfate, and tetrathionate and its reduction of nitrate, nitrite, ferric citrate, FeOOH, and anthraquinone-2,6-disulfonic acid. Similarly, the omcBmutant (OMCB1) grew on fumarate, nitrate, TMAO, and thiosulfate and reduced ferric citrate and FeOOH. However, OMCA1 and OMCB1 were 45 and 75% slower than MR-1, respectively, at reducing MnO2. OMCA1 lacked only OmcA. While OMCB1 lacked OmcB, other OM cytochromes were also missing or markedly depressed. The total cytochrome content of the OM of OMCB1 was less than 15% of that of MR-1. Western blots demonstrated that OMCB1 still synthesized OmcA, but most of it was localized in the cytoplasmic membrane and soluble fractions rather than in the OM. OMCB1 had therefore lost the ability to properly localize multiple OM cytochromes to the OM. Together, the results suggest that the OM cytochromes of MR-1 participate in the reduction of Mn(IV) but are not required for the reduction of Fe(III) or other electron acceptors.

Download Full-text

Anaerobic Respiration of Elemental Sulfur and Thiosulfate by Shewanella oneidensis MR-1 Requires psrA, a Homolog of the phsA Gene of Salmonella enterica Serovar Typhimurium LT2

Applied and Environmental Microbiology ◽

10.1128/aem.00888-09 ◽

2009 ◽

Vol 75 (16) ◽

pp. 5209-5217 ◽

Cited By ~ 70

Author(s):

Justin L. Burns ◽

Thomas J. DiChristina

Keyword(s):

Gene Cluster ◽

Salmonella Enterica ◽

Elemental Sulfur ◽

Shewanella Oneidensis ◽

Anaerobic Respiration ◽

Sulfur Cycle ◽

Sulfur Compounds ◽

Electron Acceptors ◽

Inorganic Sulfur ◽

Serovar Typhimurium

ABSTRACT Shewanella oneidensis MR-1, a facultatively anaerobic gammaproteobacterium, respires a variety of anaerobic terminal electron acceptors, including the inorganic sulfur compounds sulfite (SO3 2−), thiosulfate (S2O3 2−), tetrathionate (S4O6 2−), and elemental sulfur (S0). The molecular mechanism of anaerobic respiration of inorganic sulfur compounds by S. oneidensis, however, is poorly understood. In the present study, we identified a three-gene cluster in the S. oneidensis genome whose translated products displayed 59 to 73% amino acid similarity to the products of phsABC, a gene cluster required for S0 and S2O3 2− respiration by Salmonella enterica serovar Typhimurium LT2. Homologs of phsA (annotated as psrA) were identified in the genomes of Shewanella strains that reduce S0 and S2O3 2− yet were missing from the genomes of Shewanella strains unable to reduce these electron acceptors. A new suicide vector was constructed and used to generate a markerless, in-frame deletion of psrA, the gene encoding the putative thiosulfate reductase. The psrA deletion mutant (PSRA1) retained expression of downstream genes psrB and psrC but was unable to respire S0 or S2O3 2− as the terminal electron acceptor. Based on these results, we postulate that PsrA functions as the main subunit of the S. oneidensis S2O3 2− terminal reductase whose end products (sulfide [HS−] or SO3 2−) participate in an intraspecies sulfur cycle that drives S0 respiration.

Download Full-text

NanoSIMS imaging reveals metabolic stratification within current-producing biofilms

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1912498116 ◽

2019 ◽

Vol 116 (41) ◽

pp. 20716-20724 ◽

Cited By ~ 21

Author(s):

Grayson L. Chadwick ◽

Fernanda Jiménez Otero ◽

Jeffrey A. Gralnick ◽

Daniel R. Bond ◽

Victoria J. Orphan

Keyword(s):

Secondary Ion Mass Spectrometry ◽

Anaerobic Respiration ◽

Electrical Current ◽

Total Activity ◽

Stable Isotope Probing ◽

Electron Acceptors ◽

Geobacter Sulfurreducens ◽

Cellular Growth ◽

Anode Surface ◽

Redox Potentials

Metal-reducing bacteria direct electrons to their outer surfaces, where insoluble metal oxides or electrodes act as terminal electron acceptors, generating electrical current from anaerobic respiration. Geobacter sulfurreducens is a commonly enriched electricity-producing organism, forming thick conductive biofilms that magnify total activity by supporting respiration of cells not in direct contact with electrodes. Hypotheses explaining why these biofilms fail to produce higher current densities suggest inhibition by formation of pH, nutrient, or redox potential gradients; but these explanations are often contradictory, and a lack of direct measurements of cellular growth within biofilms prevents discrimination between these models. To address this fundamental question, we measured the anabolic activity of G. sulfurreducens biofilms using stable isotope probing coupled to nanoscale secondary ion mass spectrometry (nanoSIMS). Our results demonstrate that the most active cells are at the anode surface, and that this activity decreases with distance, reaching a minimum 10 µm from the electrode. Cells nearest the electrode continue to grow at their maximum rate in weeks-old biofilms 80-µm-thick, indicating nutrient or buffer diffusion into the biofilm is not rate-limiting. This pattern, where highest activity occurs at the electrode and declines with each cell layer, is present in thin biofilms (<5 µm) and fully grown biofilms (>20 µm), and at different anode redox potentials. These results suggest a growth penalty is associated with respiring insoluble electron acceptors at micron distances, which has important implications for improving microbial electrochemical devices as well as our understanding of syntrophic associations harnessing the phenomenon of microbial conductivity.

Download Full-text

Genomic Variations Underlying Speciation and Niche Specialization of Shewanella baltica

mSystems ◽

10.1128/msystems.00560-19 ◽

2019 ◽

Vol 4 (5) ◽

Cited By ~ 2

Author(s):

Jie Deng ◽

Jennifer M. Auchtung ◽

Konstantinos T. Konstantinidis ◽

Ingrid Brettar ◽

Manfred G. Höfle ◽

...

Keyword(s):

Baltic Sea ◽

Water Column ◽

Transition Zone ◽

Anaerobic Respiration ◽

Electron Acceptors ◽

Gene Content ◽

Content Type ◽

Genomic Variations ◽

Niche Specialization ◽

Shewanella Baltica

ABSTRACT Shewanella baltica was the dominant culturable nitrate-reducing bacterium in the eutrophic and strongly stratified Baltic Sea in the 1980s, where it primarily inhabited the oxic-anoxic transition zone. The genomic structures of 46 of these isolates were investigated through comparative genomic hybridization (CGH), which revealed a gradient of genomic similarity, ranging from 65% to as high as 99%. The core genome of the S. baltica species was enriched in anaerobic respiration-associated genes. Auxiliary genes, most of which locate within a few genomic islands (GIs), were nonuniformly distributed among the isolates. Specifically, hypothetical and mobile genetic element (MGE)-associated genes dominated intraclade gene content differences, whereas gain/loss of functional genes drove gene content differences among less related strains. Among the major S. baltica clades, gene signatures related to specific redox-driven and spatial niches within the water column were identified. For instance, genes involved in anaerobic respiration of sulfur compounds may provide key adaptive advantages for clade A strains in anoxic waters where sulfur-containing electron acceptors are present. Genes involved in cell motility, in particular, a secondary flagellar biosynthesis system, may be associated with the free-living lifestyle by clade E strains. Collectively, this study revealed characteristics of genome variations present in the water column and active speciation of S. baltica strains, driven by niche partitioning and horizontal gene transfer (HGT). IMPORTANCE Speciation in nature is a fundamental process driving the formation of the vast microbial diversity on Earth. In the central Baltic Sea, the long-term stratification of water led to formation of a large-scale vertical redoxcline that provided a gradient of environmental niches with respect to the availability of electron acceptors and donors. The region was home to Shewanella baltica populations, which composed the dominant culturable nitrate-reducing bacteria, particularly in the oxic-anoxic transition zone. Using the collection of S. baltica isolates as a model system, genomic variations showed contrasting gene-sharing patterns within versus among S. baltica clades and revealed genomic signatures of S. baltica clades related to redox niche specialization as well as particle association. This study provides important insights into genomic mechanisms underlying bacterial speciation within this unique natural redoxcline.

Download Full-text

In Situ Bioremediation Techniques to Reduce Total Organic Matter Oversaturation of Fluvial Sediments: An Experimental Study

Applied Sciences ◽

10.3390/app10124308 ◽

2020 ◽

Vol 10 (12) ◽

pp. 4308

Author(s):

Carlos Rochera ◽

Antonio Picazo ◽

Nayeli Murueta ◽

Antonio Camacho

Keyword(s):

Organic Matter ◽

Anaerobic Respiration ◽

Electron Acceptors ◽

Biologically Active ◽

Inorganic Nutrients ◽

Limiting Factors ◽

Bacterial Strains ◽

In Situ Experiment ◽

Significant Drop

An in situ experiment was performed in sediments of River Magro (east Spain) in order to evaluate the usefulness of microbial bioremediation, both bioaugmentation and biostimulation, as a tool for reducing the excessive organic matter (OM) content in dammed river stretches due to historical wastewater spilling. The study had a prospective approach focused on the application of a biologically active commercial product (BAP), consisting of a mix of bacterial strains, ectoenzymes, and nutrients, where a range of concentrations and temporal dosages of the product were experimentally assayed in situ. They were further combined with the addition of potential organic enhancers, such as acetate, as well as of inhibitors of specific microbial guilds. On the other hand, inorganic electron acceptors for the anaerobic respiration of the organic matter were additionally amended. In additional assays, the BAP additions were combined with inorganic nutrients amendments, or even the latter were tested alone. These combinative treatments aimed at exploring the possible enhancement of synergistic or antagonistic interactions among the amended compounds, as well as the eventual effect of growth limiting factors. The single BAP additions of 50 g/m3 led to OM reductions of up to 17%, and significant removals of nitrogen or phosphorus were additionally observed by increasing or by fractioning the BAP dosage, respectively. However, a better response using the same amount of the BAP was obtained by supplementing it with sodium acetate. In this case, reductions of the OM content reached up to 35% of the accumulated OM, thus indicating that a complementary stimulus is still necessary to run out barriers towards the final steps of the anaerobic OM digestion. This treatment was also linked to the strongest significant drop in the TP content of the sediments. Neither the addition of inorganic electron acceptors nor inorganic nutrients improved the results, or they were even antagonistic of the degradative potential of the BAP product. Apparently, the occurrence of acetoclastic microorganisms, which was demonstrated by high throughput DNA-sequencing, was critical for the optimal OM reductions in the sediments. This exploratory study demonstrates that the applicability of BAPs can be extended to cover the remediation of fluvial ecosystems, and support the complementarity of different bioremediation strategies.

Download Full-text

Oxidative respiration through the bd-I and cbb3 oxidases is required for Vibrio cholerae pathogenicity and proliferation in vivo.

10.1101/2021.11.11.468188 ◽

2021 ◽

Author(s):

Andrew John Van Alst ◽

Lucas Maurice Demey ◽

Victor DiRita

Keyword(s):

Vibrio Cholerae ◽

Anaerobic Respiration ◽

Bacterial Pathogen ◽

Population Expansion ◽

Amplicon Sequencing ◽

Electron Acceptors ◽

Infant Mouse ◽

Small Intestinal ◽

Oxidative Respiration

Vibrio cholerae respires both aerobically and anaerobically and, while oxygen may be available to it during infection, other terminal electron acceptors are proposed for population expansion during infection. Unlike gastrointestinal pathogens that stimulate significant inflammation leading to elevated levels of oxygen or alternative terminal electron acceptors, V. cholerae infections are not understood to induce a notable inflammatory response. To ascertain the respiration requirements of V. cholerae during infection, we used Multiplex Genome Editing by Natural Transformation (MuGENT) to create V. cholerae strains lacking aerobic or anaerobic respiration. V. cholerae strains lacking aerobic respiration were attenuated in infant mice 10 5 -fold relative to wild type, while strains lacking anaerobic respiration had no colonization defect, contrary to earlier work suggesting a role for anaerobic respiration during infection. Using several approaches, including one we developed for this work termed Comparative Multiplex PCR Amplicon Sequencing (CoMPAS), we determined that the bd-I and cbb3 oxidases are essential for small intestinal colonization of V. cholerae in the infant mouse. The bd-I oxidase was also determined as the primary oxidase during growth outside the host, making V. cholerae the only example of a Gram-negative bacterial pathogen in which a bd-type oxidase is the primary oxidase for energy acquisition inside and outside of a host.

Download Full-text

Usage of ferrum (ІІІ) and manganese (IV) ions as electron acceptors by Desulfuromonas sp. bacteria

Biosystems Diversity ◽

10.15421/011610 ◽

2016 ◽

Vol 24 (1) ◽

pp. 87-95 ◽

Cited By ~ 1

Author(s):

O. M. Moroz ◽

S. O. Hnatush ◽

C. I. Bohoslavets ◽

G. V. Yavorska ◽

N. V. Truchym

Keyword(s):

Heavy Metal ◽

Metal Ions ◽

Anaerobic Respiration ◽

Biomass Accumulation ◽

Culture Liquid ◽

Electron Acceptors ◽

Metal Compounds ◽

Insignificant Difference ◽

High Concentrations ◽

Reducing Bacteria

The toxicity of metal ions to microorganisms, in particular at high concentrations, is one of the main impediments to their usage in remediation technologies. The purpose of this work is to analyze the possibility of usage by bacteria of the Desulfuromonas genus, isolated by us from Yavorivske Lake, of ferrum (ІІІ) and manganese (IV) ions at concentrations in the medium of 1,74–10,41 mM as electron acceptors of anaerobic respiration to assesss resistance of sulphur reducing bacteria strains to heavy metal compounds. Cells of Desulfuromonas acetoxidans ІМV V-7384, Desulfuromonas sp. Yavor-5 and Desulfuromonas sp. Yavor-7 were cultivated for 10 days at 30 °C under anaerobic conditions in Kravtsov-Sorokin’s medium without sulphate ions, sulphur, with cysteine as the sulphur source (0.2 g/l) and sodium lactate or citrate as the electron donor (17.86 g/l), in which were added sterile 1 M solutions of C6H5O7Fe and C4H4O4 (control) and also weights of MnO2 to their terminal concentrations 1.74, 3.47, 5.21, 6.94, 10.41 mM. Biomass was determined by the turbidimetric method. In the culture liquid the presence of Fe3+ and Mn4+ were qualitatively determined, and the content of Fe2+ in reaction with о-phenanthroline was determined quantitatively. It was established that sulphur reducing bacteria used with different intensity ferrum (ІІІ) and manganese (IV) ions as electron acceptors during the process of anaerobic respiration at concentrations of 1.74–10.41 mM C6H5O7Fe and MnO2 in the medium, which demonstrated the important role of the investigated microorganisms in reductive detoxication of natural and technogenic media from oxidized forms of transitional heavy metals. An insignificant difference in biomass accumulation during usage of 5.21–10.41 mM ferrum (ІІІ) ions and fumarate is caused by toxicity of the metal ions to cells since the high redox potential of the Fe(III)/Fe(ІІ) pair with increase in concentrations of electron acceptors in the medium did not lead to increase in the biomass accumulation level. The greatest biomass of the bacteria accumulated on the 8–10th days in the medium with the lowest concentration of C6H5O7Fe – 1.74 mM (up to 2.77 g/l), and the lowest biomass – with highest concentration – 10.41 mM (up to 2.41 g/l). After 10 days of cultivation the bacteria of all strains had fully used the ferrum (ІІІ) ions present in the medium. A biomass yield almost twice as low was revealed after manganese (IV) oxide was used by bacteria compared with its use of ferrum (ІІІ) citrate and fumarate at all studied concentrations of electron acceptors in the medium. The highest biomass of bacteria accumulated in the medium with the lowest MnO2 content – 1.74 mM (up to 1.35 g/l), and the lowest biomass in the medium with the highest content – 10.41 mM (up to 1.15 g/l). After 10 days of cultivation bacteria of all strains had not fully restored the manganese (IV) ions present in the medium. The greatest biomass compared with other strains after growth in medium with different C6H5O7Fe and MnO2 contents was accumulated by the strain Desulfuromonas sp. Yavor-7. Since sulphur reducing bacteria strains proved to be resistant to Fe3+ and Mn4+ high concentrations (up to10.41 mM) they can be successfully used in technologies of environmenal remediation from sulphur and heavy metal compounds.

Download Full-text

The Dynamic Interactions between Salmonella and the Microbiota, within the Challenging Niche of the Gastrointestinal Tract

International Scholarly Research Notices ◽

10.1155/2014/846049 ◽

2014 ◽

Vol 2014 ◽

pp. 1-23 ◽

Cited By ~ 7

Author(s):

C. M. Anjam Khan

Keyword(s):

Gastrointestinal Tract ◽

Inflammatory Responses ◽

Anaerobic Respiration ◽

Electron Acceptors ◽

Effector Proteins ◽

Host Cells ◽

Gastrointestinal Microbiota ◽

Dynamic Interactions ◽

Fierce Competition ◽

Type 3

Understanding how Salmonella species establish successful infections remains a foremost research priority. This gastrointestinal pathogen not only faces the hostile defenses of the host’s immune system, but also faces fierce competition from the large and diverse community of microbiota for space and nutrients. Salmonella have solved these challenges ingeniously. To jump-start growth, Salmonella steal hydrogen produced by the gastrointestinal microbiota. Type 3 effector proteins are subsequently secreted by Salmonella to trigger potent inflammatory responses, which generate the alternative terminal electron acceptors tetrathionate and nitrate. Salmonella exclusively utilize these electron acceptors for anaerobic respiration, permitting metabolic access to abundant substrates such as ethanolamine to power growth blooms. Chemotaxis and flagella-mediated motility enable the identification of nutritionally beneficial niches. The resulting growth blooms also promote horizontal gene transfer amongst the resident microbes. Within the gastrointestinal tract there are opportunities for chemical signaling between host cells, the microbiota, and Salmonella. Host produced catecholamines and bacterial autoinducers form components of this chemical dialogue leading to dynamic interactions. Thus, Salmonella have developed remarkable strategies to initially shield against host defenses and to transiently compete against the intestinal microbiota leading to successful infections. However, the immunocompetent host is subsequently able to reestablish control and clear the infection.

Download Full-text