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Journal of Applied Microbiology Aug 1998Ecological and physiological effects of the sulphate-reducing bacterium (SRB) Desulfovibrio desulfuricans on other intestinal organisms were investigated in anaerobic...
Ecological and physiological effects of the sulphate-reducing bacterium (SRB) Desulfovibrio desulfuricans on other intestinal organisms were investigated in anaerobic chemostats (dilution rate approximately 0.2 h-1). Reproducible defined bacterial communities were used in these experiments, comprising 14 different saccharolytic and amino acid fermenting species: Bifidobacterium longum, Bif. adolescentis, Bif. pseudolongum, Bif. infantis, Bacteroides thetaiotaomicron, Bact. vulgatus, Lactobacillus acidophilus, Enterococcus faecalis, Ent. faecium, Escherichia coli, Clostridium perfringens, Cl. butyricum, Cl. innocuum, Cl. bifermentans. Lactobacillus and Cl. bifermentans populations never rose above minimum detection limits (log10 2.0 and 4.0, respectively) under the experimental conditions employed in these studies. Inclusion of Des. desulfuricans in bacterial cultures (c. log10 8.4 viable cells ml-1) resulted in marked reductions (i.e. greater than 1 log) in planktonic cell population densities of several species, particularly Bif. longum, Cl. perfringens and Bif. pseudolongum. The two bacteroides species were unaffected by Des. desulfuricans, while numbers of Cl. butyricum increased. Extensive wall growth developed in the SRB culture, consisting mainly of Des. desulfuricans (log10 9.2 viable cells ml-1), Bact. thetaiotaomicron and Bact. vulgatus, with lesser numbers of facultative anaerobes, Cl. perfringens and Bif. longum. Wall growth was associated with a reduction in planktonic cell mass and increased acid production by the cultures. Chemotaxonomic study of chemostat microbiotas, on the basis of cellular fatty acid methyl ester (FAME) analyses, showed the existence of characteristic bacteroides (C15) and bifidobacterial (C18) markers, but desulfovibrio markers (i-C15:0, C16:0, i-C17:1) could be identified. The metabolic activities of saccharolytic organisms were altered in the SRB chemostat, including synthesis of a number of hydrolytic enzymes involved in carbohydrate breakdown, such as alpha-galactosidase, alpha-glucosidase and beta-galactosidase, together with several mucinolytic enzymes. High concentrations of sulphide (8.2 mmol 1-1) were detected in the SRB chemostat, suggesting that this metabolite may have been inhibitory to some species. Saccharolytic organisms growing in the SRB fermenter utilized more starch, but less galactose-containing polymers, which correlated with the observed glycosidase activities. Profound differences were also recorded with respect to fermentation product formation in the chemostats, where a major switch to acetate production occurred in the SRB culture, with concomitant reductions in propionate, butyrate and lactate, which is an important electron donor for desulfovibrios.
Topics: Amino Acids; Carbohydrate Metabolism; Desulfovibrio; Fermentation; Humans
PubMed: 9750310
DOI: 10.1046/j.1365-2672.1998.00522.x -
Nature Communications Oct 2020Six CO fixation pathways are known to operate in photoautotrophic and chemoautotrophic microorganisms. Here, we describe chemolithoautotrophic growth of the...
Six CO fixation pathways are known to operate in photoautotrophic and chemoautotrophic microorganisms. Here, we describe chemolithoautotrophic growth of the sulphate-reducing bacterium Desulfovibrio desulfuricans (strain G11) with hydrogen and sulphate as energy substrates. Genomic, transcriptomic, proteomic and metabolomic analyses reveal that D. desulfuricans assimilates CO via the reductive glycine pathway, a seventh CO fixation pathway. In this pathway, CO is first reduced to formate, which is reduced and condensed with a second CO to generate glycine. Glycine is further reduced in D. desulfuricans by glycine reductase to acetyl-P, and then to acetyl-CoA, which is condensed with another CO to form pyruvate. Ammonia is involved in the operation of the pathway, which is reflected in the dependence of the autotrophic growth rate on the ammonia concentration. Our study demonstrates microbial autotrophic growth fully supported by this highly ATP-efficient CO fixation pathway.
Topics: Adenosine Triphosphate; Ammonia; Autotrophic Processes; Bacterial Proteins; Carbon Dioxide; Desulfovibrio desulfuricans; Gene Expression Profiling; Genome, Bacterial; Glycine; Metabolomics
PubMed: 33037220
DOI: 10.1038/s41467-020-18906-7 -
The Biochemical Journal Aug 2004Fru-2,6-P2 (fructose 2,6-bisphosphate) is a signal molecule that controls glycolysis. Since its discovery more than 20 years ago, inroads have been made towards the... (Review)
Review
Fru-2,6-P2 (fructose 2,6-bisphosphate) is a signal molecule that controls glycolysis. Since its discovery more than 20 years ago, inroads have been made towards the understanding of the structure-function relationships in PFK-2 (6-phosphofructo-2-kinase)/FBPase-2 (fructose-2,6-bisphosphatase), the homodimeric bifunctional enzyme that catalyses the synthesis and degradation of Fru-2,6-P2. The FBPase-2 domain of the enzyme subunit bears sequence, mechanistic and structural similarity to the histidine phosphatase family of enzymes. The PFK-2 domain was originally thought to resemble bacterial PFK-1 (6-phosphofructo-1-kinase), but this proved not to be correct. Molecular modelling of the PFK-2 domain revealed that, instead, it has the same fold as adenylate kinase. This was confirmed by X-ray crystallography. A PFK-2/FBPase-2 sequence in the genome of one prokaryote, the proteobacterium Desulfovibrio desulfuricans, could be the result of horizontal gene transfer from a eukaryote distantly related to all other organisms, possibly a protist. This, together with the presence of PFK-2/FBPase-2 genes in trypanosomatids (albeit with possibly only one of the domains active), indicates that fusion of genes initially coding for separate PFK-2 and FBPase-2 domains might have occurred early in evolution. In the enzyme homodimer, the PFK-2 domains come together in a head-to-head like fashion, whereas the FBPase-2 domains can function as monomers. There are four PFK-2/FBPase-2 isoenzymes in mammals, each coded by a different gene that expresses several isoforms of each isoenzyme. In these genes, regulatory sequences have been identified which account for their long-term control by hormones and tissue-specific transcription factors. One of these, HNF-6 (hepatocyte nuclear factor-6), was discovered in this way. As to short-term control, the liver isoenzyme is phosphorylated at the N-terminus, adjacent to the PFK-2 domain, by PKA (cAMP-dependent protein kinase), leading to PFK-2 inactivation and FBPase-2 activation. In contrast, the heart isoenzyme is phosphorylated at the C-terminus by several protein kinases in different signalling pathways, resulting in PFK-2 activation.
Topics: Amino Acid Sequence; Animals; Glycolysis; Humans; Models, Biological; Models, Molecular; Molecular Sequence Data; Phosphofructokinase-2
PubMed: 15170386
DOI: 10.1042/BJ20040752 -
Angewandte Chemie (International Ed. in... Sep 2020The incorporation of highly active but also highly sensitive catalysts (e.g. the [FeFe] hydrogenase from Desulfovibrio desulfuricans) in biofuel cells is still one of...
The incorporation of highly active but also highly sensitive catalysts (e.g. the [FeFe] hydrogenase from Desulfovibrio desulfuricans) in biofuel cells is still one of the major challenges in sustainable energy conversion. We report the fabrication of a dual-gas diffusion electrode H /O biofuel cell equipped with a [FeFe] hydrogenase/redox polymer-based high-current-density H -oxidation bioanode. The bioanodes show benchmark current densities of around 14 mA cm and the corresponding fuel cell tests exhibit a benchmark for a hydrogenase/redox polymer-based biofuel cell with outstanding power densities of 5.4 mW cm at 0.7 V cell voltage. Furthermore, the highly sensitive [FeFe] hydrogenase is protected against oxygen damage by the redox polymer and can function under 5 % O .
Topics: Bioelectric Energy Sources; Biofuels; Desulfovibrio desulfuricans; Diffusion; Electrodes; Hydrogen; Hydrogenase; Molecular Structure; Oxidation-Reduction; Oxygen; Polymers
PubMed: 32432842
DOI: 10.1002/anie.202006824 -
FEBS Letters Jan 2015The levels of sulfate-reducing bacteria (SRB), including Desulfovibrionaceae, in the gut increase following a fat-enriched diet. Endotoxins from gut microbiota...
The levels of sulfate-reducing bacteria (SRB), including Desulfovibrionaceae, in the gut increase following a fat-enriched diet. Endotoxins from gut microbiota contribute to the inflammation process, leading to metabolic diseases. Thus, we sought to characterize the lipid A structures of Desulfovibrionaceae lipopolysaccharides (LPS) that are associated with the microbiota inflammatory properties. LPS variants were obtained from two SRB isolates from the gut of a single individual. These LPS variants shared similar lipid A moieties with Enterobacterial LPS, but differed from one another with regard to fatty-acid numbers and endotoxic activity. This first complete structural characterization of Desulfovibrio lipid A gives new insights into previously published data on Desulfovibrio lipid A biosynthesis. LPS microdiversity within SRBs illustrates how adaptation can influence pro-inflammatory potential.
Topics: Carbohydrate Conformation; Desulfovibrio desulfuricans; Humans; Intestines; Lipid A
PubMed: 25479086
DOI: 10.1016/j.febslet.2014.11.042 -
Journal of Bacteriology Dec 1962Akagi, J. M. (University of Kansas, Lawrence) and L. Leon Campbell. Studies on thermophilic sulfate-reducing bacteria. III. Adenosine triphosphate-sulfurylase of...
Akagi, J. M. (University of Kansas, Lawrence) and L. Leon Campbell. Studies on thermophilic sulfate-reducing bacteria. III. Adenosine triphosphate-sulfurylase of Clostridium nigrificans and Desulfovibrio desulfuricans. J. Bacteriol. 84:1194-1201. 1962.-Adenosine triphosphate (ATP)-sulfurylase, which catalyzes the formation of adenosine-5'-phosphosulfate (APS) from ATP and SO(4) (=), has been purified from crude extracts of Clostridium nigrificans and Desulfovibrio desulfuricans by (NH(4))(2)SO(4) fractionation and triethylaminoethyl column chromatography. The enzyme from both sources operates over a broad pH range from 6.0 to 9.5. Below pH 6.0, activity decreases sharply, with no detectable activity at pH 5.0. Of the nucleotides tested (ATP and the triphosphates of deoxyadenosine, uridine, inosine, and guanosine), only ATP was acted upon by the enzyme from either source. The enzyme requires Mg(++) for activity. Incubation of the enzyme from both organisms with ATP and S(35)O(4) (=) in the presence of helium resulted in the formation of an S(35)-labeled nucleotide whose electrophoretic mobility was identical to that of chemically prepared APS. When incubated with ATP and the group VI anions (CrO(4), MoO(4), WO(4)), the enzyme from both organisms formed an unstable intermediate, resulting in the accumulation of pyrophosphate. Thermal stability studies revealed that the ATP-sulfurylase of C. nigrificans was stable at higher temperatures than the enzyme obtained from D. desulfuricans. Exposure of the enzyme from C. nigrificans to 65 C for 2 hr gave virtually no decrease in activity. In contrast, the enzyme from D. desulfuricans was completely inactivated after 30 min at 55 C, after 3 min at 60 C, or after 1 min at 65 C.
PubMed: 16561978
DOI: 10.1128/jb.84.6.1194-1201.1962 -
Antimicrobial Agents and Chemotherapy Oct 2002Desulfovibrio spp. are gram-negative anaerobes phylogenetically related to Bacteroides spp., which are rarely isolated and which are mostly isolated from intra-abdominal...
Desulfovibrio spp. are gram-negative anaerobes phylogenetically related to Bacteroides spp., which are rarely isolated and which are mostly isolated from intra-abdominal abscesses. Desulfovibrio desulfuricans clinical isolate D3 had a clavulanic acid-inhibited beta-lactam resistance profile and was resistant to some expanded-spectrum cephalosporins. A beta-lactamase gene, bla(DES-1), was cloned from whole-cell DNA of isolate D3 and expressed in Escherichia coli. Purified beta-lactamase DES-1, with a pI value of 9.1, had a relative molecular mass of ca. 31 kDa and a mature protein of 288 amino acids. DES-1 was distantly related to Ambler class A beta-lactamases and most closely related to PenA from Burkholderia pseudomallei (48% amino acid identity). It was weakly related to class A beta-lactamases CblA, CepA, CfxA, and CfxA2 from other anaerobic species, Bacteroides spp. and Prevotella intermedia. Its hydrolysis spectrum included amino- and ureidopenicillins, narrow-spectrum cephalosporins, ceftriaxone, and cefoperazone. bla(DES-1)-like genes were not identified in phylogenetically related Desulfovibrio fairfieldensis isolates. However, they were found in some but not all D. desulfuricans strains, thus suggesting that these genes may be present in a given D. desulfuricans subspecies.
Topics: Amino Acid Sequence; Base Sequence; Cloning, Molecular; Desulfovibrio; Humans; Microbial Sensitivity Tests; Molecular Sequence Data; Polymerase Chain Reaction; beta-Lactamases; beta-Lactams
PubMed: 12234847
DOI: 10.1128/AAC.46.10.3215-3222.2002 -
Journal of Conservative Dentistry : JCD 2020This study determined the corrosion rate by mass loss caused by oral strains of sulphate-reducing bacteria (SRB) in Kerr endodontic files (KF), aiming the development of...
AIMS
This study determined the corrosion rate by mass loss caused by oral strains of sulphate-reducing bacteria (SRB) in Kerr endodontic files (KF), aiming the development of a biopharmaceutical that facilitates the removal of endodontic limb fragments from root canals.
MATERIALS AND METHODS
Nine new KF were analyzed after immersion in the modified Postgate E culture medium inoculated with oral (84 days), in the consortium (84 days) and environmental (119 days).
RESULTS
Optical microscopy revealed corrosion suggestive areas in all files submitted to immersion in SRB cultures, presenting a statistical difference ( < 0.05) between the samples environmental and KF control and between oral and KF control. Epifluorescence microscopy revealed an active SRB biofilm over the entire metal surface of the KF, as evidenced by the SYTO 9 fluorophore.
CONCLUSION
SRB were capable of promoting biocorrosion in Kerr type endodontic files, but with low rate.
PubMed: 33384495
DOI: 10.4103/JCD.JCD_64_19 -
Applied and Environmental Microbiology Oct 2001The toxicity of copper [Cu(II)] to sulfate-reducing bacteria (SRB) was studied by using Desulfovibrio desulfuricans G20 in a medium (MTM) developed specifically to test...
The toxicity of copper [Cu(II)] to sulfate-reducing bacteria (SRB) was studied by using Desulfovibrio desulfuricans G20 in a medium (MTM) developed specifically to test metal toxicity to SRB (R. K. Sani, G. Geesey, and B. M. Peyton, Adv. Environ. Res. 5:269-276, 2001). The effects of Cu(II) toxicity were observed in terms of inhibition in total cell protein, longer lag times, lower specific growth rates, and in some cases no measurable growth. At only 6 microM, Cu(II) reduced the maximum specific growth rate by 25% and the final cell protein concentration by 18% compared to the copper-free control. Inhibition by Cu(II) of cell yield and maximum specific growth rate increased with increasing concentrations. The Cu(II) concentration causing 50% inhibition in final cell protein was evaluated to be 16 microM. A Cu(II) concentration of 13.3 microM showed 50% inhibition in maximum specific growth rate. These results clearly show significant Cu(II) toxicity to SRB at concentrations that are 100 times lower than previously reported. No measurable growth was observed at 30 microM Cu(II) even after a prolonged incubation of 384 h. In contrast, Zn(II) and Pb(II), at 16 and 5 microM, increased lag times by 48 and 72 h, respectively, but yielded final cell protein concentrations equivalent to those of the zinc- and lead-free controls. Live/dead staining, based on membrane integrity, indicated that while Cu(II), Zn(II), and Pb(II) inhibited growth, these metals did not cause a loss of D. desulfuricans membrane integrity. The results show that D. desulfuricans in the presence of Cu(II) follows a growth pattern clearly different from the pattern followed in the presence of Zn(II) or Pb(II). It is therefore likely that Cu(II) toxicity proceeds by a mechanism different from that of Zn(II) or Pb(II) toxicity.
Topics: Bacterial Proteins; Copper; Culture Media; Desulfovibrio; Lead; Zinc
PubMed: 11571183
DOI: 10.1128/AEM.67.10.4765-4772.2001 -
Case Reports in Infectious Diseases 2015Desulfovibrio spp. are gram-negative, sulfate-reducing, and anaerobic bacteria found in the digestive tract of humans. Because Desulfovibrio spp. are infrequent...
Desulfovibrio spp. are gram-negative, sulfate-reducing, and anaerobic bacteria found in the digestive tract of humans. Because Desulfovibrio spp. are infrequent causative agents of infectious diseases and are difficult to isolate and to identify from clinical specimens, the appropriate antibiotic therapy to infection with Desulfovibrio spp. has not been determined. We report the first case of liver abscess with bacteremia due to Desulfovibrio desulfuricans to show the clinical presentation and treatment. The patient was successfully treated with intravenous piperacillin-tazobactam and oral amoxicillin-clavulanic acid.
PubMed: 25632357
DOI: 10.1155/2015/354168