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Applied Microbiology and Biotechnology Jun 2023Microbiologically influenced corrosion is a common problem in the industrial field due to the deterioration of metals in the presence of various microorganisms, in...
Microbiologically influenced corrosion is a common problem in the industrial field due to the deterioration of metals in the presence of various microorganisms, in particular sulfate-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB). A common method to reduce microbiologically influenced corrosion is the application of biocides. The limited number of suitable biocides and the resulting development of resistance, high dosage, and high application rate hinder an effective application. An environmentally friendly alternative could be the application of antimicrobial peptides (AMP), which have already been established in the field of medical devices for a while. Here, the successful treatment of different AMPs against 3 SRB and 1 SOB was demonstrated. The peptide L5K5W was favored due to its broad activity, high stability, and simple structure resulting in low synthesis costs. An alanine scan showed that substitution of leucine with tryptophan increased the activity of this peptide twofold compared to the original peptide against D. vulgaris, the main representative of SRB. Additional optimization of this modified peptide through changes in amino acid composition and lipidations significantly increased the effectiveness, finally resulting in a minimum inhibitory concentration (MIC) of 15.63 μg/mL against Desulfovibrio vulgaris. Even against the marine SRB Desulfovibrio indonesiensis with a required salt concentration of min. 2%, an activity of the peptides can be observed (MIC: 31.25 μg/mL). The peptides also remained stable and active for 7 days in the supernatant of the bacterial culture. KEY POINTS: • Antimicrobial peptides provide an alternative to combat biocorrosive bacteria. • Optimization of the peptide sequence leads to a significant increase in activity. • The investigated peptides exhibit high stability, both in the medium and in the bacterial supernatant.
Topics: Antimicrobial Peptides; Biofilms; Desulfovibrio vulgaris; Bacteria; Disinfectants; Desulfovibrio; Corrosion
PubMed: 37154907
DOI: 10.1007/s00253-023-12562-9 -
Scientific Reports Sep 2018The intestinal microbiota plays a key role in the maintenance of human health. Alterations in this microbiota have been described in several autoimmune diseases,...
The intestinal microbiota plays a key role in the maintenance of human health. Alterations in this microbiota have been described in several autoimmune diseases, including nervous system diseases. Nevertheless, the information regarding neuromuscular conditions is still limited. In this study, we aimed at characterizing the intestinal microbiota composition in myasthenia gravis patients (MG). To this end fecal samples were taken from ten patients, with antibodies against the acetylcholine receptor, and ten age and sex matched controls from the same population (Asturias region, Spain). Fecal samples were submitted to microbiota analyses by 16S rRNA gene profiling, bifidobacterial ITS-region profiling and qPCR. The fecal levels of short chain fatty acids were determined by gas chromatography. MG patients were found to harbor lower relative proportions of Verrucomicrobiaceae and Bifidobacteriaceae, among others, and increased of the phylum Bacteroidetes and the family Desulfovibrionaceae. The increase of these latter microbial groups was also confirmed at quantitative level by qPCR. In contrast, no statistically significant differences were found between MG patients and the control group in the bifidobacterial population at the species level or in short chain fatty acids profiles. Our data indicates an altered fecal microbiota pattern in MG patients and point out at specific microbiota targets for intervention in this population.
Topics: Aged; Aged, 80 and over; Bacteroidetes; Bifidobacterium; Desulfovibrionaceae; Feces; Female; Gastrointestinal Microbiome; Humans; Male; Middle Aged; Myasthenia Gravis; RNA, Ribosomal, 16S; Transcriptome; Verrucomicrobia
PubMed: 30258104
DOI: 10.1038/s41598-018-32700-y -
BMC Microbiology Dec 2021Bilophila wadsworthia, a strictly anaerobic, sulfite-reducing bacterium and common member of the human gut microbiota, has been associated with diseases such as...
BACKGROUND
Bilophila wadsworthia, a strictly anaerobic, sulfite-reducing bacterium and common member of the human gut microbiota, has been associated with diseases such as appendicitis and colitis. It is specialized on organosulfonate respiration for energy conservation, i.e., utilization of dietary and host-derived organosulfonates, such as taurine (2-aminoethansulfonate), as sulfite donors for sulfite respiration, producing hydrogen sulfide (HS), an important intestinal metabolite that may have beneficial as well as detrimental effects on the colonic environment. Its taurine desulfonation pathway involves the glycyl radical enzyme (GRE) isethionate sulfite-lyase (IslAB), which cleaves isethionate (2-hydroxyethanesulfonate) into acetaldehyde and sulfite.
RESULTS
We demonstrate that taurine metabolism in B. wadsworthia 3.1.6 involves bacterial microcompartments (BMCs). First, we confirmed taurine-inducible production of BMCs by proteomic, transcriptomic and ultra-thin sectioning and electron-microscopical analyses. Then, we isolated BMCs from taurine-grown cells by density-gradient ultracentrifugation and analyzed their composition by proteomics as well as by enzyme assays, which suggested that the GRE IslAB and acetaldehyde dehydrogenase are located inside of the BMCs. Finally, we are discussing the recycling of cofactors in the IslAB-BMCs and a potential shuttling of electrons across the BMC shell by a potential iron-sulfur (FeS) cluster-containing shell protein identified by sequence analysis.
CONCLUSIONS
We characterized a novel subclass of BMCs and broadened the spectrum of reactions known to take place enclosed in BMCs, which is of biotechnological interest. We also provided more details on the energy metabolism of the opportunistic pathobiont B. wadsworthia and on microbial HS production in the human gut.
Topics: Bacterial Proteins; Bilophila; Cell Compartmentation; Gastrointestinal Microbiome; Gene Expression Profiling; Humans; Hydrogen Sulfide; Isethionic Acid; Proteomics; Sulfites; Taurine
PubMed: 34903181
DOI: 10.1186/s12866-021-02386-w -
Scientific Reports Jul 2017Surface nanopatterning of metals has been an effective technique for improved performance and functionalization. However, it is of great challenge to fabricate...
Surface nanopatterning of metals has been an effective technique for improved performance and functionalization. However, it is of great challenge to fabricate nanostructure on carbon steels despite their extensive use and urgent needs to maintain the performance reliability and durability. Here, we report a one-step anodization technique to nanopattern a carbon steel in 50 wt.% NaOH solution for highly effective anti-adhesion by sulphate reducing bacteria (SRB), i.e., Desulfovibrio desulfuricans subsp. desulfuricans (Beijerinck) Kluyver and van Niel. We characterize the morphology, structure, composition, and surface roughness of the nanostructured film formed on the steel as a function of anodizing potential. We quantify the surface hydrophobicity by contact angle measurements, and the SRB adhesion by fluorescent analysis. The optimal anodization potential of 2.0 V is determined for the best performance of anti-adhesion of SRB to the steel, resulting in a 23.5 times of reduction of SRB adhesion compared to bare steel. We discuss the mechanisms for the film formation on the steel during anodization, and the high-performance anti-adhesion of bacteria to nanopatterned steels. Our technique is simple, cost-effective and environment-friendly, providing a promising alternative for industry-scale surface nanopatterning of carbon steels for effective controlling of bacterial adhesion.
Topics: Bacterial Adhesion; Desulfovibrio desulfuricans; Hydrophobic and Hydrophilic Interactions; Nanotubes, Carbon; Steel; Surface Properties
PubMed: 28706204
DOI: 10.1038/s41598-017-05626-0 -
Briefings in Functional Genomics &... Jun 2006The response of Desulfovibrio vulgaris Hildenborough (DvH), a sulphate-reducing bacterium, to nitrate stress was examined using quantitative proteomic analysis. DvH was... (Review)
Review
The response of Desulfovibrio vulgaris Hildenborough (DvH), a sulphate-reducing bacterium, to nitrate stress was examined using quantitative proteomic analysis. DvH was stressed with 105 mM sodium nitrate (NaNO(3)), a level that caused a 50% inhibition in growth. The protein profile of stressed cells was compared with that of cells grown in the absence of nitrate using the iTRAQ peptide labelling strategy and tandem liquid chromatography separation coupled with mass spectrometry (quadrupole time-of-flight) detection. A total of 737 unique proteins were identified by two or more peptides, representing 22% of the total DvH proteome and spanning every functional category. The results indicate that this was a mild stress, as proteins involved in central metabolism and the sulphate reduction pathway were unperturbed. Proteins involved in the nitrate reduction pathway increased. Increases seen in transport systems for proline, glycine-betaine and glutamate indicate that the NaNO(3) exposure led to both salt stress and nitrate stress. Up-regulation observed in oxidative stress response proteins (Rbr, RbO, etc.) and a large number of ABC transport systems as well as in iron-sulphur-cluster-containing proteins, however, appear to be specific to nitrate exposure. Finally, a number of hypothetical proteins were among the most significant changers, indicating that there may be unknown mechanisms initiated upon nitrate stress in DvH.
Topics: Desulfovibrio vulgaris; Nitrates; Oxidative Stress; Proteome; Proteomics
PubMed: 16772278
DOI: 10.1093/bfgp/ell025 -
Scientific Reports Jul 2023Mediation by sulphate-reducing bacteria (SRB) is responsible for pyrite (FeS) formation. The origin of the Dachang tin polymetallic ore field is related to the...
Mediation by sulphate-reducing bacteria (SRB) is responsible for pyrite (FeS) formation. The origin of the Dachang tin polymetallic ore field is related to the mineralisation of submarine hydrothermal vent sediments. Here, we investigated SRB in these ores via morphological, chemical, and isotopic analyses. Polarised and scanning electron microscopy indicated that trace SRB fossils in the metal sulphide ore were present in the form of tubular, beaded, and coccoidal bodies comprising FeS and were enclosed within a pyrrhotite (FeS) matrix in the vicinity of micro-hydrothermal vents. The carbon (C), nitrogen (N), and oxygen (O) contents in the FeS synthesised by SRB were high, and a clear biological Raman signal was detected. No such signals were discerned in the peripheral FeS. This co-occurrence of FeS, FeS, and the remains of bacteria (probably chemoautotrophic bacteria) was interpreted as the coprecipitation process of SRB-mediated FeS formation, which has, to the best of our knowledge, not been reported before. Our study also illustrates that combined energy-dispersive X-ray spectroscopy, Raman spectroscopy, and isotopic analysis can be used as a novel methodology to document microbial-mediated processes of mineral deposition in submarine hydrothermal vent ecology on geological time scales.
Topics: Tin; China; Sulfides; Bacteria; Desulfovibrio; Sulfates
PubMed: 37468706
DOI: 10.1038/s41598-023-38827-x -
The ISME Journal Nov 2020Elevated nitrate in the environment inhibits sulfate reduction by important microorganisms of sulfate-reducing bacteria (SRB). Several SRB may respire nitrate to survive...
Elevated nitrate in the environment inhibits sulfate reduction by important microorganisms of sulfate-reducing bacteria (SRB). Several SRB may respire nitrate to survive under elevated nitrate, but how SRB that lack nitrate reductase survive to elevated nitrate remains elusive. To understand nitrate adaptation mechanisms, we evolved 12 populations of a model SRB (i.e., Desulfovibrio vulgaris Hildenborough, DvH) under elevated NaNO for 1000 generations, analyzed growth and acquired mutations, and linked their genotypes with phenotypes. Nitrate-evolved (EN) populations significantly (p < 0.05) increased nitrate tolerance, and whole-genome resequencing identified 119 new mutations in 44 genes of 12 EN populations, among which six functional gene groups were discovered with high mutation frequencies at the population level. We observed a high frequency of nonsense or frameshift mutations in nitrosative stress response genes (NSR: DVU2543, DVU2547, and DVU2548), nitrogen regulatory protein C family genes (NRC: DVU2394-2396, DVU2402, and DVU2405), and nitrate cluster (DVU0246-0249 and DVU0251). Mutagenesis analysis confirmed that loss-of-functions of NRC and NSR increased nitrate tolerance. Also, functional gene groups involved in fatty acid synthesis, iron regulation, and two-component system (LytR/LytS) known to be responsive to multiple stresses, had a high frequency of missense mutations. Mutations in those gene groups could increase nitrate tolerance through regulating energy metabolism, barring entry of nitrate into cells, altering cell membrane characteristics, or conferring growth advantages at the stationary phase. This study advances our understanding of nitrate tolerance mechanisms and has important implications for linking genotypes with phenotypes in DvH.
Topics: Desulfovibrio; Desulfovibrio vulgaris; Genotype; Nitrates; Nitrogen Oxides; Oxidation-Reduction; Sulfates
PubMed: 32934357
DOI: 10.1038/s41396-020-00753-5 -
Lipids in Health and Disease Jul 2018Gut microbiota plays an important role in many metabolic diseases such as diabetes and atherosclerosis. Apolipoprotein E (apoE) knock-out (KO) mice are frequently used...
BACKGROUND
Gut microbiota plays an important role in many metabolic diseases such as diabetes and atherosclerosis. Apolipoprotein E (apoE) knock-out (KO) mice are frequently used for the study of hyperlipidemia and atherosclerosis. However, it is unknown whether apoE KO mice have altered gut microbiota when challenged with a Western diet.
METHODS
In the current study, we assessed the gut microbiota profiling of apoE KO mice and compared with wild-type mice fed either a normal chow or Western diet for 12 weeks using 16S pyrosequencing.
RESULTS
On a western diet, the gut microbiota diversity was significantly decreased in apoE KO mice compared with wild type (WT) mice. Firmicutes and Erysipelotrichaceae were significantly increased in WT mice but Erysipelotrichaceae was unchanged in apoE KO mice on a Western diet. The weighted UniFrac principal coordinate analysis exhibited clear separation between WT and apoE KO mice on the first vector (58.6%) with significant changes of two dominant phyla (Bacteroidetes and Firmicutes) and seven dominant families (Porphyromonadaceae, Lachnospiraceae, Ruminococcaceae, Desulfovibrionaceae, Helicobacteraceae, Erysipelotrichaceae and Veillonellaceae). Lachnospiraceae was significantly enriched in apoE KO mice on a Western diet. In addition, Lachnospiraceae and Ruminococcaceae were positively correlated with relative atherosclerosis lesion size in apoE KO.
CONCLUSIONS
Collectively, our study showed that there are marked changes in the gut microbiota of apoE KO mice, particularly challenged with a Western diet and these alterations may be possibly associated with atherosclerosis.
Topics: Animals; Apolipoproteins E; Atherosclerosis; Bacteroidetes; DNA, Ribosomal; Desulfovibrionaceae; Diet, Western; Disease Models, Animal; Firmicutes; Gastrointestinal Microbiome; Helicobacteraceae; Hyperlipidemias; Lipids; Male; Mice; Mice, Inbred C57BL; Mice, Knockout, ApoE; Porphyromonas; RNA, Ribosomal, 16S; Ruminococcus; Sequence Analysis, DNA; Severity of Illness Index; Veillonellaceae
PubMed: 30021609
DOI: 10.1186/s12944-018-0811-8 -
PloS One 2021Methanol is often considered as a non-competitive substrate for methanogenic archaea, but an increasing number of sulfate-reducing microorganisms (SRMs) have been...
Methanol is often considered as a non-competitive substrate for methanogenic archaea, but an increasing number of sulfate-reducing microorganisms (SRMs) have been reported to be capable of respiring with methanol as an electron donor. A better understanding of the fate of methanol in natural or artificial anaerobic systems thus requires knowledge of the methanol dissimilation by SRMs. In this study, we describe the growth kinetics and sulfur isotope effects of Desulfovibrio carbinolicus, a methanol-oxidizing sulfate-reducing deltaproteobacterium, together with its genome sequence and annotation. D. carbinolicus can grow with a series of alcohols from methanol to butanol. Compared to longer-chain alcohols, however, specific growth and respiration rates decrease by several fold with methanol as an electron donor. Larger sulfur isotope fractionation accompanies slowed growth kinetics, indicating low chemical potential at terminal reductive steps of respiration. In a medium containing both ethanol and methanol, D. carbinolicus does not consume methanol even after the cessation of growth on ethanol. Among the two known methanol dissimilatory systems, the genome of D. carbinolicus contains the genes coding for alcohol dehydrogenase but lacks enzymes analogous to methanol methyltransferase. We analyzed the genomes of 52 additional species of sulfate-reducing bacteria that have been tested for methanol oxidation. There is no apparent relationship between phylogeny and methanol metabolizing capacity, but most gram-negative methanol oxidizers grow poorly, and none carry homologs for methyltransferase (mtaB). Although the amount of available data is limited, it is notable that more than half of the known gram-positive methanol oxidizers have both enzymatic systems, showing enhanced growth relative to the SRMs containing only alcohol dehydrogenase genes. Thus, physiological, genomic, and sulfur isotopic results suggest that D. carbinolicus and close relatives have the ability to metabolize methanol but likely play a limited role in methanol degradation in most natural environments.
Topics: Cell Respiration; Desulfovibrio; Genome, Bacterial; Genomics; Methanol; Phylogeny; RNA, Ribosomal, 16S; Sulfur Isotopes
PubMed: 33444327
DOI: 10.1371/journal.pone.0245069 -
Microbiome Dec 2018Currently, the effect of the bacterial community on cast iron corrosion process does not reach consensus. Moreover, some studies have produced contrasting results,...
BACKGROUND
Currently, the effect of the bacterial community on cast iron corrosion process does not reach consensus. Moreover, some studies have produced contrasting results, suggesting that bacteria can either accelerate or inhibit corrosion.
RESULTS
The long-term effects of the bacterial community on cast iron corrosion in reclaimed wastewater distribution systems were investigated from both spatial (yellow layer vs. black layer) and temporal (1-year dynamic process) dimensions of the iron coupon-reclaimed wastewater microcosm using high-throughput sequencing and flow cytometry approaches. Cast iron coupons in the NON and UV reactors suffered more severe corrosion than did those in the NaClO reactor. The bacterial community significantly promoted cast iron corrosion, which was quantified for the first time in the practical reclaimed wastewater and found to account for at least 30.5% ± 9.7% of the total weight loss. The partition of yellow and black layers of cast iron corrosion provided more accurate information on morphology and crystal structures for corrosion scales. The black layer was dense, and the particles looked fusiform, while the yellow layer was loose, and the particles were ellipse or spherical. Goethite was the predominant crystalline phase in black layers, while corrosion products mainly existed as an amorphous phase in yellow layers. The bacterial community compositions of black layers were distinctly separated from yellow layers regardless of disinfection methods. The NON and UV reactors had a more similar microbial composition and variation tendency for the same layer type than did the NaClO reactor. Biofilm development can be divided into the initial start-up stage, mid-term development stage, and terminal stable stage. In total, 12 potential functional genera were selected to establish a cycle model for Fe, N, and S metabolism. Desulfovibrio was considered to accelerate the transfer of Fe to Fe and speed up weight loss.
CONCLUSION
The long-term effect of disinfection processes on corrosion behaviors of cast iron in reclaimed wastewater distribution systems and the hidden mechanisms were deciphered for the first time. This study established a cycle model for Fe, N, and S metabolism that involved 12 functional genera and discovered the significant contribution of Desulfovibrio in promoting corrosion.
Topics: Bacteria; Biofilms; Bioreactors; Corrosion; DNA, Bacterial; Desulfovibrio; High-Throughput Nucleotide Sequencing; Iron; Iron Compounds; Minerals; Sequence Analysis, DNA; Spatio-Temporal Analysis; Wastewater
PubMed: 30545419
DOI: 10.1186/s40168-018-0610-5