Nitrous Oxide Metabolism in Nitrate-Reducing Bacteria

AbstractProbiotics are the living microorganisms that have been commonly used in the prevention of gastrointestinal disorders. In recent times, probiotic and prebiotics have been used to assess and develop a natural balance of the microbial flora in the respiratory tract and the oral cavity as an adjunct therapy. They are known to augment the existing microbial flora that is beneficial to the host. Prebiotics are nondigestible food ingredients that help in increasing populations of probiotic bacteria. Recent studies have shown that probiotics help in active reduction in gingivitis, dental caries, periodontitis, and halitosis by replacing the harmful oral species, by means of utilizing abundant health-associated oral microbial species. Additionally, the nitrate-reducing bacteria have shown promising effect in improving efficiency of probiotic strains to accentuate oral health benefits. Probiotics along with prebiotics effectively alter the host–microbial interface by achieving homeostasis in multifactorial diseases such as periodontal diseases and oral malodor. The aim of the review is to collate the existing information available on use of probiotics and prebiotics in oral cavity.

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Two Marine Desulfotomaculum spp. of Different Origin are Capable of Utilizing Acetone and Higher Ketones

Current Microbiology ◽

10.1007/s00284-021-02441-9 ◽

2021 ◽

Author(s):

Jasmin Frey ◽

Sophie Kaßner ◽

Bernhard Schink

Keyword(s):

Sulfate Reducing Bacteria ◽

Thiamine Diphosphate ◽

Sulfate Reducers ◽

Sulfate Reducing ◽

Reducing Bacteria ◽

Nitrate Reducing Bacteria ◽

Different Origin

AbstractDegradation of acetone and higher ketones has been described in detail for aerobic and nitrate-reducing bacteria. Among sulfate-reducing bacteria, degradation of acetone and other ketones is still an uncommon ability and has not been understood completely yet. In the present work, we show that Desulfotomaculum arcticum and Desulfotomaculum geothermicum are able to degrade acetone and butanone. Total proteomics of cell-free extracts of both organisms indicated an involvement of a thiamine diphosphate-dependent enzyme, a B12-dependent mutase, and a specific dehydrogenase during acetone degradation. Similar enzymes were recently described to be involved in acetone degradation by Desulfococcus biacutus. As there are so far only two described sulfate reducers able to degrade acetone, D. arcticum and D. geothermicum represent two further species with this capacity. All these bacteria appear to degrade acetone via the same set of enzymes and therefore via the same pathway.

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Isolation and Characterization of Nitrate Reducing Bacteria for Conversion of Vegetable-Derived Nitrate to ‘Natural Nitrite’

Applied Microbiology ◽

10.3390/applmicrobiol1010002 ◽

2021 ◽

Vol 1 (1) ◽

pp. 11-23

Author(s):

Arjun Bhusal ◽

Peter M. Muriana

Keyword(s):

Nitrate Reduction ◽

High Performance ◽

Limit Of Detection ◽

Reversed Phase ◽

Test Tube ◽

Screening Assay ◽

Isolation And Characterization ◽

The Us ◽

Reducing Bacteria ◽

Nitrate Reducing Bacteria

In the US, sodium nitrate is used as a preservative and curing agent in processed meats and is therefore a regulated ingredient. Nitrate reducing bacteria (NRB) can convert vegetable nitrate into nitrite allowing green/clean label status in the US as per the USDA-FSIS definition of ‘natural nitrite’. The current ‘in-liquid’ test tube assay for detecting nitrite is not suitable for screening mixtures of bacteria nor is commercial nitrate broth suitable for growth of many Gram (+) bacteria. M17 broth was therefore used to develop M17-nitrate broth to be inclusive of Gram (+) bacteria. An ‘on-agar’ colony-screening assay was developed to detect the conversion of nitrate to nitrite on agar plates and could detect one NRB+ colony among ~300–500 colonies on a single plate. Samples that might have NRB were spread-plated on M17 agar plates, sandwiched with nitrate agar, and after incubation followed with sequential agar overlays containing the reagents used in the nitrate reduction assay; the appearance of red color zones above colonies indicated the presence of nitrite. NRB derived from various samples were confirmed for nitrate conversion and both nitrate and nitrite were quantified by C8 reversed-phase (RP) ion-pairing high performance liquid chromatography (HPLC) analysis (1 ppm limit of detection). Staphylococcus carnosus, a strain commonly used for nitrate reduction, was able to convert 1100 ppm M17-nitrate broth to 917 ppm nitrite. Staphylococcus caprae and Panteoa agglomerans, NRB isolated using the M17-nitrate agar assay, were also able to ferment the same broth to 916 ppm and 867 ppm nitrite, respectively. This is the first report of an on-agar colony screening assay for the detection and isolation of nitrite reducing bacteria allowing NRB to be readily isolated. This may allow for the identification of new bacteria that may have a more efficient process to generate nitrite, and possibly concomitant with production of additional natural antimicrobials, as vegetable nitrite becomes more widely used to prevent spore germination.

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Activation of short-chain ketones and isopropanol in sulfate-reducing bacteria

BMC Microbiology ◽

10.1186/s12866-021-02112-6 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Jasmin Frey ◽

Sophie Kaßner ◽

Dieter Spiteller ◽

Mario Mergelsberg ◽

Matthias Boll ◽

...

Keyword(s):

Sulfate Reducing Bacteria ◽

Short Chain ◽

Enzyme Assays ◽

Protein Patterns ◽

Sulfate Reducing ◽

Protein Gel ◽

Branched Chain ◽

Reducing Bacteria ◽

Coenzyme B ◽

Nitrate Reducing Bacteria

Abstract Background Degradation of acetone by aerobic and nitrate-reducing bacteria can proceed via carboxylation to acetoacetate and subsequent thiolytic cleavage to two acetyl residues. A different strategy was identified in the sulfate-reducing bacterium Desulfococcus biacutus that involves formylation of acetone to 2-hydroxyisobutyryl-CoA. Results Utilization of short-chain ketones (acetone, butanone, 2-pentanone and 3-pentanone) and isopropanol by the sulfate reducer Desulfosarcina cetonica was investigated by differential proteome analyses and enzyme assays. Two-dimensional protein gel electrophoresis indicated that D. cetonica during growth with acetone expresses enzymes homologous to those described for Desulfococcus biacutus: a thiamine diphosphate (TDP)-requiring enzyme, two subunits of a B12-dependent mutase, and a NAD+-dependent dehydrogenase. Total proteomics of cell-free extracts confirmed these results and identified several additional ketone-inducible proteins. Acetone is activated, most likely mediated by the TDP-dependent enzyme, to a branched-chain CoA-ester, 2-hydroxyisobutyryl-CoA. This compound is linearized to 3-hydroxybutyryl-CoA by a coenzyme B12-dependent mutase followed by oxidation to acetoacetyl-CoA by a dehydrogenase. Proteomic analysis of isopropanol- and butanone-grown cells revealed the expression of a set of enzymes identical to that expressed during growth with acetone. Enzyme assays with cell-free extract of isopropanol- and butanone-grown cells support a B12-dependent isomerization. After growth with 2-pentanone or 3-pentanone, similar protein patterns were observed in cell-free extracts as those found after growth with acetone. Conclusions According to these results, butanone and isopropanol, as well as the two pentanone isomers, are degraded by the same enzymes that are used also in acetone degradation. Our results indicate that the degradation of several short-chain ketones appears to be initiated by TDP-dependent formylation in sulfate-reducing bacteria.

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Increased replication of dissimilatory nitrate-reducing bacteria leads to decreased anammox bioreactor performance

Microbiome ◽

10.1186/s40168-020-0786-3 ◽

2020 ◽

Vol 8 (1) ◽

Cited By ~ 3

Author(s):

Ray Keren ◽

Jennifer E. Lawrence ◽

Weiqin Zhuang ◽

David Jenkins ◽

Jillian F. Banfield ◽

...

Keyword(s):

Reducing Bacteria ◽

Nitrate Reducing Bacteria ◽

Bioreactor Performance

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Impact of Intensive Land-Based Fish Culture in Qingdao, China, on the Bacterial Communities in Surrounding Marine Waters and Sediments

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2011/487543 ◽

2011 ◽

Vol 2011 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Qiufen Li ◽

Yan Zhang ◽

David Juck ◽

Nathalie Fortin ◽

Charles W. Greer

Keyword(s):

Bacterial Communities ◽

Gel Electrophoresis ◽

Denaturing Gradient Gel Electrophoresis ◽

Fish Culture ◽

Fish Ponds ◽

Marine Area ◽

Gradient Gel Electrophoresis ◽

Reducing Bacteria ◽

The Impact ◽

Nitrate Reducing Bacteria

The impact of intensive land-based fish culture in Qingdao, China, on the bacterial communities in surrounding marine environment was analyzed. Culture-based studies showed that the highest counts of heterotrophic, ammonium-oxidizing, nitrifying, and nitrate-reducing bacteria were found in fish ponds and the effluent channel, with lower counts in the adjacent marine area and the lowest counts in the samples taken from 500 m off the effluent channel. Denaturing gradient gel electrophoresis (DGGE) analysis was used to assess total bacterial diversity. Fewer bands were observed from the samples taken from near the effluent channel compared with more distant sediment samples, suggesting that excess nutrients from the aquaculture facility may be reducing the diversity of bacterial communities in nearby sediments. Phylogenetic analysis of the sequenced DGGE bands indicated that the bacteria community of fish-culture-associated environments was mainly composed of Flavobacteriaceae, gamma- and deltaproteobacteria, including generaGelidibacter, Psychroserpen, Lacinutrix,andCroceimarina.

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Biogeochemical Modelling of Uranium Immobilization and Aquifer Remediation Strategies Near NCCP Sludge Storage Facilities

Applied Sciences ◽

10.3390/app11062875 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2875

Author(s):

A.V. Safonov ◽

A.E. Boguslavsky ◽

O.L. Gaskova ◽

K.A. Boldyrev ◽

O.S. Shvartseva ◽

...

Keyword(s):

Sandy Loam ◽

Influential Factor ◽

Rrna Gene ◽

16S Rrna Gene Analysis ◽

Long Term Stability ◽

Microbial Biofilms ◽

Remediation Strategies ◽

Reducing Bacteria ◽

Nitrate Reducing Bacteria ◽

Storage Facilities

Nitrate is a substance which influences the prevailing redox conditions in groundwater, and in turn the behaviour of U. The study of groundwater in an area with low-level radioactive sludge storage facilities has shown their contamination with sulphate and nitrate anions, uranium, and some associated metals. The uranyl ion content in the most contaminated NO3–Cl–SO4–Na borehole is 2000 times higher (1.58 mg/L) than that in the background water. At the same time, assessment of the main physiological groups of microorganisms showed a maximum number of denitrifying and sulphate-reducing bacteria (e.g., Sulfurimonas) in the water from the same borehole. Biogenic factors of radionuclide immobilization on sandy rocks of upper aquifers have been experimentally investigated. Different reduction rates of NO3-, SO42-, Fe(III) and U(VI) with stimulated microbial activity were dependent on the pollution degree. Moreover, 16S rRNA gene analysis of the microbial community after whey addition revealed a significant decrease in microbial diversity and the activation of nonspecific nitrate-reducing bacteria (genera Rhodococcus and Rhodobacter). The second influential factor can be identified as the formation of microbial biofilms on the sandy loam samples, which has a positive effect on U sorption (an increase in Kd value is up to 35%). As PHREEQC physicochemical modelling numerically confirmed, the third most influential factor that drives U mobility is the biogenic-mediated formation of a sulphide redox buffer. This study brings important information, which helps to assess the long-term stability of U in the environment of radioactive sludge storage facilities.

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Community composition of nitrous oxide reducing bacteria investigated using a functional gene microarray

Deep Sea Research Part II Topical Studies in Oceanography ◽

10.1016/j.dsr2.2018.10.002 ◽

2018 ◽

Vol 156 ◽

pp. 44-50 ◽

Cited By ~ 2

Author(s):

A. Jayakumar ◽

D. Balachandran ◽

A.P. Rees ◽

P.J. Kearns ◽

J.L. Bowen ◽

...

Keyword(s):

Nitrous Oxide ◽

Community Composition ◽

Functional Gene ◽

Gene Microarray ◽

Reducing Bacteria

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Migraines Are Correlated with Higher Levels of Nitrate-, Nitrite-, and Nitric Oxide-Reducing Oral Microbes in the American Gut Project Cohort

mSystems ◽

10.1128/msystems.00105-16 ◽

2016 ◽

Vol 1 (5) ◽

Cited By ~ 19

Author(s):

Antonio Gonzalez ◽

Embriette Hyde ◽

Naseer Sangwan ◽

Jack A. Gilbert ◽

Erik Viirre ◽

...

Keyword(s):

Nitric Oxide ◽

Cardiovascular Health ◽

Commensal Bacteria ◽

Common Side Effect ◽

Symbiotic Relationship ◽

Link Type ◽

Downstream Effects ◽

Reducing Bacteria ◽

Nitrate Reducing Bacteria ◽

Nitric Oxide Pathway

ABSTRACT Recent work has demonstrated a potentially symbiotic relationship between oral commensal bacteria and humans through the salivary nitrate-nitrite-nitric oxide pathway (C. Duncan et al., Nat Med 1:546–551, 1995, http://dx.doi.org/10.1038/nm0695-546 ). Oral nitrate-reducing bacteria contribute physiologically relevant levels of nitrite and nitric oxide to the human host that may have positive downstream effects on cardiovascular health (V. Kapil et al., Free Radic Biol Med 55:93–100, 2013, http://dx.doi.org/10.1016/j.freeradbiomed.2012.11.013 ). In the work presented here, we used 16S rRNA Illumina sequencing to determine whether a connection exists between oral nitrate-reducing bacteria, nitrates for cardiovascular disease, and migraines, which are a common side effect of nitrate medications (U. Thadani and T. Rodgers, Expert Opin Drug Saf 5:667–674, 2006, http://dx.doi.org/10.1517/14740338.5.5.667 ). Nitrates, such as cardiac therapeutics and food additives, are common headache triggers, with nitric oxide playing an important role. Facultative anaerobic bacteria in the oral cavity may contribute migraine-triggering levels of nitric oxide through the salivary nitrate-nitrite-nitric oxide pathway. Using high-throughput sequencing technologies, we detected observable and significantly higher abundances of nitrate, nitrite, and nitric oxide reductase genes in migraineurs versus nonmigraineurs in samples collected from the oral cavity and a slight but significant difference in fecal samples. IMPORTANCE Recent work has demonstrated a potentially symbiotic relationship between oral commensal bacteria and humans through the salivary nitrate-nitrite-nitric oxide pathway (C. Duncan et al., Nat Med 1:546–551, 1995, http://dx.doi.org/10.1038/nm0695-546 ). Oral nitrate-reducing bacteria contribute physiologically relevant levels of nitrite and nitric oxide to the human host that may have positive downstream effects on cardiovascular health (V. Kapil et al., Free Radic Biol Med 55:93–100, 2013, http://dx.doi.org/10.1016/j.freeradbiomed.2012.11.013 ). In the work presented here, we used 16S rRNA Illumina sequencing to determine whether a connection exists between oral nitrate-reducing bacteria, nitrates for cardiovascular disease, and migraines, which are a common side effect of nitrate medications (U. Thadani and T. Rodgers, Expert Opin Drug Saf 5:667–674, 2006, http://dx.doi.org/10.1517/14740338.5.5.667 ).

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