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

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.

scholarly journals Stenotrophomonas terrae sp. nov. and Stenotrophomonas humi sp. nov., two nitrate-reducing bacteria isolated from soil

2007 ◽  
Vol 57 (9) ◽  
pp. 2056-2061 ◽  
Author(s):  
Kim Heylen ◽  
Bram Vanparys ◽  
Filip Peirsegaele ◽  
Liesbeth Lebbe ◽  
Paul De Vos
Keyword(s):  
Soil Analysis ◽  
Rrna Gene ◽  
Biochemical Tests ◽  
Gene Sequence Analysis ◽  
Species Analysis ◽  
Different Strains ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria ◽  
Type Strains ◽  
Physiological And Biochemical

Three Gram-negative, rod-shaped, non-spore-forming, nitrate-reducing isolates (R-32746, R-32768T and R-32729T) were obtained from soil. Analysis of repetitive sequence-based PCR showed that the three isolates represented two different strains. 16S rRNA gene sequence analysis and DNA–DNA hybridization placed them within the genus Stenotrophomonas and revealed that they were genotypically different from each other and from all recognized Stenotrophomonas species. Analysis of the fatty acid composition and physiological and biochemical tests allowed differentiation from their closest phylogenetic neighbours. They are therefore considered to represent two novel species, for which the names Stenotrophomonas terrae sp. nov. and Stenotrophomonas humi sp. nov. are proposed, with strains R-32768T (=LMG 23958T=DSM 18941T) and R-32729T (=LMG 23959T=DSM 18929T), respectively, as the type strains.

MORPHOLOGICAL AND PHYSIOLOGICAL GROUPS OF SOIL BACTERIA FROM THE ROOTS OF BARLEY AND OATS

1956 ◽  
Vol 2 (5) ◽  
pp. 473-481 ◽  
Author(s):  
H. DeL. King ◽  
R. H. Wallace
Keyword(s):  
Soil Bacteria ◽  
Sandy Loam ◽  
The Other ◽  
Physiological Characteristics ◽  
Gram Positive ◽  
Gram Negative ◽  
Rhizosphere Soils ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria ◽  
Percentage Incidence

Morphological and physiological characteristics were studied of more than 2400 stock-cultures of bacteria isolated from rhizosphere soils of barley and oats, and from control soils. Gram-positive rods were proportionately more numerous in control soils than in rhizosphere soils; this difference was greater with oats than with barley. The proportion of Gram-negative rods was greater in rhizosphere soils than in controls but not more so for one crop than the other. Gram-positive rods replaced a significant portion of Gram-negative rods in soils of the mature barley plants. The only significant increase in percentage incidence of physiological groups in rhizosphere soils was in regard to nitrate-reducing bacteria of the young oats plants. On the other hand there were significantly smaller percentages for starch-hydrolyzing bacteria and gelatin liquefiers in oats rhizospheres than in the controls. There were not any significant differences between rhizospheres and controls with regard to physiological groups from the barley plants. It is concluded that the proportional incidences of some physiological groups of soil bacteria are not greatly increased, but in some instances are decreased, by the presence of barley or oat roots growing in Chicot sandy loam.

scholarly journals Microbiome of Odontogenic Abscesses

2021 ◽  
Vol 9 (6) ◽  
pp. 1307
Author(s):  
Sebastian Böttger ◽  
Silke Zechel-Gran ◽  
Daniel Schmermund ◽  
Philipp Streckbein ◽  
Jan-Falco Wilbrand ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Oral Microbiome ◽  
Minor Role ◽  
Rrna Gene ◽  
Sequencing Analysis ◽  
Bacterial Strains ◽  
16S Rrna Gene Analysis ◽  
Odontogenic Infections ◽  
Odontogenic Abscess

Severe odontogenic abscesses are regularly caused by bacteria of the physiological oral microbiome. However, the culture of these bacteria is often prone to errors and sometimes does not result in any bacterial growth. Furthermore, various authors found completely different bacterial spectra in odontogenic abscesses. Experimental 16S rRNA gene next-generation sequencing analysis was used to identify the microbiome of the saliva and the pus in patients with a severe odontogenic infection. The microbiome of the saliva and the pus was determined for 50 patients with a severe odontogenic abscess. Perimandibular and submandibular abscesses were the most commonly observed diseases at 15 (30%) patients each. Polymicrobial infections were observed in 48 (96%) cases, while the picture of a mono-infection only occurred twice (4%). On average, 31.44 (±12.09) bacterial genera were detected in the pus and 41.32 (±9.00) in the saliva. In most cases, a predominantly anaerobic bacterial spectrum was found in the pus, while saliva showed a similar oral microbiome to healthy individuals. In the majority of cases, odontogenic infections are polymicrobial. Our results indicate that these are mainly caused by anaerobic bacterial strains and that aerobic and facultative anaerobe bacteria seem to play a more minor role than previously described by other authors. The 16S rRNA gene analysis detects significantly more bacteria than conventional methods and molecular methods should therefore become a part of routine diagnostics in medical microbiology.

scholarly journals Effect of Probiotics and Prebiotics on Oral Health

2021 ◽  
Author(s):  
Goutam Nanavati ◽  
T. Prasanth ◽  
Manab Kosala ◽  
Sujit K. Bhandari ◽  
Pamil Banotra
Keyword(s):  
Oral Health ◽  
Oral Cavity ◽  
Periodontal Diseases ◽  
Microbial Flora ◽  
Gastrointestinal Disorders ◽  
Food Ingredients ◽  
Multifactorial Diseases ◽  
Probiotic Strains ◽  
Reducing Bacteria ◽  
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.

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

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.

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

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.

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

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.

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

Microbiome ◽  
2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Ray Keren ◽  
Jennifer E. Lawrence ◽  
Weiqin Zhuang ◽  
David Jenkins ◽  
Jillian F. Banfield ◽  
...  
Keyword(s):  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria ◽  
Bioreactor Performance

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

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
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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