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Genome Announcements Oct 2014MI agar is routinely used for quantifying Escherichia coli in drinking water. A suspect E. coli colony isolated from a water sample was identified as Buttiauxella...
MI agar is routinely used for quantifying Escherichia coli in drinking water. A suspect E. coli colony isolated from a water sample was identified as Buttiauxella agrestis. The whole genome sequence of B. agrestis was determined to understand the genetic basis for its phenotypic resemblance to E. coli on MI agar.
PubMed: 25323724
DOI: 10.1128/genomeA.01060-14 -
FEMS Microbiology Letters Mar 2018Four facultative anaerobic and two obligate anaerobic bacteria were isolated from extreme environments (deep subsurface halite mine, sulfidic anoxic spring, mineral-rich...
Four facultative anaerobic and two obligate anaerobic bacteria were isolated from extreme environments (deep subsurface halite mine, sulfidic anoxic spring, mineral-rich river) in the frame MASE (Mars Analogues for Space Exploration) project. The isolates were investigated under anoxic conditions for their survivability after desiccation up to 6 months and their tolerance to ionizing radiation up to 3000 Gy. The results indicated that tolerances to both stresses are strain-specific features. Yersinia intermedia MASE-LG-1 showed a high desiccation tolerance but its radiation tolerance was very low. The most radiation-tolerant strains were Buttiauxella sp. MASE-IM-9 and Halanaerobium sp. MASE-BB-1. In both cases, cultivable cells were detectable after an exposure to 3 kGy of ionizing radiation, but cells only survived desiccation for 90 and 30 days, respectively. Although a correlation between desiccation and ionizing radiation resistance has been hypothesized for some aerobic microorganisms, our data showed that there was no correlation between tolerance to desiccation and ionizing radiation, suggesting that the physiological basis of both forms of tolerances is not necessarily linked. In addition, these results indicated that facultative and obligate anaerobic organisms living in extreme environments possess varied species-specific tolerances to extremes.
Topics: Adaptation, Biological; Bacteria; Bacterial Physiological Phenomena; Desiccation; Environmental Microbiology; Extreme Environments; Hypoxia; Microbial Viability; Radiation Tolerance; Radiation, Ionizing
PubMed: 29474542
DOI: 10.1093/femsle/fny044 -
Poultry Science Nov 2019The anti-nutritional effects of dietary inositol phosphates (IP6 through IP3) have been recognized in broiler chickens; however, inositol hexaphosphate (IP6) is more...
The efficacy of 2 phytases on inositol phosphate degradation in different segments of the gastrointestinal tract, calcium and phosphorus digestibility, and bone quality of broilers.
The anti-nutritional effects of dietary inositol phosphates (IP6 through IP3) have been recognized in broiler chickens; however, inositol hexaphosphate (IP6) is more potent than the lower IP esters. The efficacies of 2 commercial phytases, a Buttiauxella sp. phytase (BSP) and a Citrobacter braakii phytase (CBP) at 500 and 1,000 FTU/kg, were studied on IP6-3 concentrations in the crop, proventriculus + gizzard, and distal ileum digesta, and ileal IP6 disappearance in broilers at day 22. Apparent ileal P and Ca digestibility, and bone quality at days 22 and 33 were also measured. Female Ross 308 broilers (n = 1,890; 30 birds × 7 diets × 9 replicates) were fed corn-soy-based crumbled diets. The 7 diets included a primary breeder recommendation-based positive control diet (PC); the PC marginally reduced in available P by 0.146% and Ca by 0.134% of the diet, (NC1) or moderately reduced by 0.174 and 0.159% of the diet, respectively (NC2). Other diets were the NC1 + BSP or CBP at 500 FTU/kg (NC1+500BSP and NC1+500CBP) and the NC2 + BSP or CBP at 1,000 FTU/kg (NC2+1,000BSP and NC2+1,000CBP). Each of the NC1 and NC2 had distal ileum IP6 disappearance similar to that of PC, but each had lower P digestibility and the majority of measured bone quality parameters than the PC. The ileal IP6 levels were decreased by 52.0 and 32.7% for NC1+500BSP and NC1+500CBP, respectively, relative to NC1 and by 73.6 and 50.9% for NC2+1,000BSP and NC2+1,000CBP, respectively, relative to NC2 (P < 0.001), with a similar effect for distal ileum IP6 disappearance. Overall, phytase in the NC diets increased P digestibility, and femur breaking strength and cortical bone mineral density at days 22 and 33. Overall, each of the phytases at each dose degraded IP6-3 across the gastrointestinal tract segments to increase P digestibility and the P and Ca utilization in bone. However, dietary BSP at 1,000 FTU/kg was most effective. Supplemental phytase degrades phytate to decrease the anti-nutritional effects in a dose- and phytase-dependent manner.
Topics: 6-Phytase; Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Bacterial Proteins; Bone Density; Calcium, Dietary; Chickens; Citrobacter; Diet; Dietary Supplements; Digestion; Enterobacteriaceae; Gastrointestinal Tract; Inositol Phosphates; Phosphorus, Dietary; Species Specificity
PubMed: 31265114
DOI: 10.3382/ps/pez375 -
Molecules (Basel, Switzerland) May 2022Acetyl xylan esterases (AXEs) are enzymes capable of hydrolysing the acetyl bonds in acetylated xylan, allowing for enhanced activity of backbone-depolymerizing enzymes....
Acetyl xylan esterases (AXEs) are enzymes capable of hydrolysing the acetyl bonds in acetylated xylan, allowing for enhanced activity of backbone-depolymerizing enzymes. Bioprospecting novel AXE is essential in designing enzyme cocktails with desired characteristics targeting the complete breakdown of lignocellulose. In this article, we report the characterisation of a novel AXE identified as Gene_id_40363 in the metagenomic library analysed from the gut microbiota of the common black slug. The conserved domain description was identified with an NCBI BLASTp search using the translated nucleotide sequence as a query. The activity of the recombinant enzyme was tested on various synthetic substrates and acetylated substrates. The protein sequence matched the conserved domain described as putative hydrolase and aligned closely to an uncharacterized esterase from , hence the designation as BaAXE. BaAXE showed low sequence similarity among characterized CE family proteins with an available 3D structure. BaAXE was active on 4-nitrophenyl acetate, reporting a specific activity of 78.12 U/mg and a Km value of 0.43 mM. The enzyme showed optimal activity at 40 °C and pH 8 and showed high thermal stability, retaining over 40% activity after 2 h of incubation from 40 °C to 100 °C. BaAXE hydrolysed acetyl bonds, releasing acetic acid from acetylated xylan and β-D-glucose pentaacetate. BaAXE has great potential for biotechnological applications harnessing its unique characteristics. In addition, this proves the possibility of bioprospecting novel enzymes from understudied environments.
Topics: Acetylesterase; Animals; Gastrointestinal Microbiome; Gastropoda; Substrate Specificity; Xylans
PubMed: 35566348
DOI: 10.3390/molecules27092999 -
Journal of Dairy Science Jan 2016The presence of coliform bacteria in pasteurized fluid milk typically indicates that product contamination occurred downstream of the pasteurizer, but it may also...
The presence of coliform bacteria in pasteurized fluid milk typically indicates that product contamination occurred downstream of the pasteurizer, but it may also indicate pasteurization failure. Although coliform detection is frequently used as a hygiene indicator for dairy products, our understanding of the taxonomic and phenotypic coliform diversity associated with dairy products is surprisingly limited. Therefore, using Petrifilm Coliform Count plates (3M, St. Paul, MN), we isolated coliforms from high-temperature, short-time (HTST)-pasteurized fluid milk samples from 21 fluid milk processing plants in the northeast United States. Based on source information and initial characterization using partial 16S rDNA sequencing, 240 nonredundant isolates were obtained. The majority of these isolates were identified as belonging to the genera Enterobacter (42% of isolates), Hafnia (13%), Citrobacter (12%), Serratia (10%), and Raoultella (9%); additional isolates were classified into the genera Buttiauxella, Cedecea, Kluyvera, Leclercia, Pantoea, and Rahnella. A subset of 104 representative isolates was subsequently characterized phenotypically. Cold growth analysis in skim milk broth showed that all isolates displayed at least a 2-log increase over 10 d at 6°C; the majority of isolates (n=74) displayed more than a 5-log increase. In total, 43% of the representative isolates displayed lipolysis when incubated on spirit blue agar at 6°C for 14 d, whereas 71% of isolates displayed proteolysis when incubated on skim milk agar at 6°C for 14 d. Our data indicate that a considerable diversity of coliforms is found in HTST-pasteurized fluid milk and that a considerable proportion of these coliforms have phenotypic characteristics that will allow them to cause fluid milk spoilage.
Topics: Animals; Cold Temperature; DNA, Bacterial; Enterobacteriaceae; Food Contamination; Food Microbiology; Hot Temperature; Milk; New England; Pasteurization; RNA, Ribosomal, 16S; Sequence Analysis, DNA
PubMed: 26547640
DOI: 10.3168/jds.2015-9728 -
Current Issues in Molecular Biology 2020Five bacterial (facultatively) anaerobic strains, namely Buttiauxella sp. MASE-IM-9, Clostridium sp. MASE-IM-4, Halanaerobium sp. MASE-BB-1, Trichococcus sp. MASE-IM-5,...
Five bacterial (facultatively) anaerobic strains, namely Buttiauxella sp. MASE-IM-9, Clostridium sp. MASE-IM-4, Halanaerobium sp. MASE-BB-1, Trichococcus sp. MASE-IM-5, and Yersinia intermedia MASE-LG-1 isolated from different extreme natural environments were subjected to Mars relevant environmental stress factors in the laboratory under controlled conditions. These stress factors encompassed low water activity, oxidizing compounds, and ionizing radiation. Stress tests were performed under permanently anoxic conditions. The survival rate after addition of sodium perchlorate (Na-perchlorate) was found to be species-specific. The inter-comparison of the five microorganisms revealed that Clostridium sp. MASE-IM-4 was the most sensitive strain (D10-value (15 min, NaClO4) = 0.6 M). The most tolerant microorganism was Trichococcus sp. MASE-IM-5 with a calculated D10-value (15 min, NaClO4) of 1.9 M. Cultivation in the presence of Na-perchlorate in Martian relevant concentrations up to 1 wt% led to the observation of chains of cells in all strains. Exposure to Na-perchlorate led to a lowering of the survival rate after desiccation. Consecutive exposure to desiccating conditions and ionizing radiation led to additive effects. Moreover, in a desiccated state, an enhanced radiation tolerance could be observed for the strains Clostridium sp. MASE-IM-4 and Trichococcus sp. MASE-IM-5. These data show that anaerobic microorganisms from Mars analogue environments can resist a variety of Martian-simulated stresses either individually or in combination. However, responses were species-specific and some Mars-simulated extremes killed certain organisms. Thus, although Martian stresses would be expected to act differentially on microorganisms, none of the expected extremes tested here and found on Mars prevent the growth of anaerobic microorganisms.
Topics: Bacteria, Anaerobic; Carnobacteriaceae; Cell Survival; Clostridium; Desiccation; Enterobacteriaceae; Extraterrestrial Environment; Extreme Environments; Firmicutes; Mars; Oxidative Stress; Perchlorates; Radiation Tolerance; Sodium Compounds; Stress, Physiological; Time Factors; Yersinia
PubMed: 31967578
DOI: 10.21775/cimb.038.103 -
Frontiers in Microbiology 2017Membrane vesicles (MVs) are secreted from a wide range of microbial species and transfer their content to other cells. Although MVs play critical roles in bacterial...
Membrane vesicles (MVs) are secreted from a wide range of microbial species and transfer their content to other cells. Although MVs play critical roles in bacterial communication, whether MVs selectively interact with bacterial cells in microbial communities is unclear. In this study, we investigated the specificity of the MV-cell interactions and evaluated the potential of MVs to target bacterial cells for delivery. MV association with bacterial cells was examined using a fluorescent membrane dye to label MVs. MVs derived from the enterobacterium specifically interacted with cells of the parent strain but interacted less specifically with those of other genera tested in this study. Electron microscopic analyses showed that MVs were not only attached on cells but also fused to them. The interaction energy, which was characterized by hydrodynamic diameter and zeta potential based on the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, was significant low between MVs and cells in , compared to those between MVs and cells of other genera. Similar specific interaction was also occurred between MVs and cells of six other species belonging to spp. harboring plasmid pBBR1MCS-1 secreted plasmid-containing MVs (p-MVs), and plasmid DNA in p-MVs was transferred to the same species. Moreover, antibiotic-associated MVs enabled effective killing of target species; the survival rate of was lower than those of and in the presence of gentamicin-associated MVs derived from . Altogether, we provide the evidence that MVs selectively interact with target bacterial cells and offer a new avenue for controlling specific bacterial species using bacterial MVs in microbial communities.
PubMed: 28439261
DOI: 10.3389/fmicb.2017.00571 -
International Journal of Infectious... May 2014Surgical site infections (SSI) are postoperative complications that constitute a major public health problem. We present a rare case report of infection by Buttiauxella...
Surgical site infections (SSI) are postoperative complications that constitute a major public health problem. We present a rare case report of infection by Buttiauxella agrestis, a member of the Enterobacteriaceae family, occurring after a cesarean delivery in a young woman with no comorbidities. The authors further discuss the origin of this infection.
Topics: Adolescent; Anti-Bacterial Agents; Cesarean Section; Enterobacteriaceae; Enterobacteriaceae Infections; Female; Humans; Postoperative Complications; Pregnancy
PubMed: 24641982
DOI: 10.1016/j.ijid.2014.01.025 -
Antimicrobial Agents and Chemotherapy Sep 2019The plasmid-located gene, encoding a putative phosphoethanolamine transferase, was identified in a colistin-resistant human fecal strain belonging to a very rare...
The plasmid-located gene, encoding a putative phosphoethanolamine transferase, was identified in a colistin-resistant human fecal strain belonging to a very rare phylogroup, the D-ST69-O15:H6 clone. This MCR-9 protein shares 33% to 65% identity with the other plasmid-encoded MCR-type enzymes identified (MCR-1 to -8) that have been found as sources of acquired resistance to polymyxins in Analysis of the lipopolysaccharide of the MCR-9-producing isolate revealed a function similar to that of MCR-1 by adding a phosphoethanolamine group to lipid A and subsequently modifying the structure of the lipopolysaccharide. However, a minor impact on susceptibility to polymyxins was noticed once the gene was cloned and produced in an K-12-derived strain. Nevertheless, we showed here that subinhibitory concentrations of colistin induced the expression of the gene, leading to increased MIC levels. This inducible expression was mediated by a two-component regulatory system encoded by the and genes located downstream of Genetic analysis showed that the gene was carried by an IncHI2 plasmid. analysis revealed that the plasmid-encoded MCR-9 shared significant amino acid identity (ca. 80%) with the chromosomally encoded MCR-like proteins from spp. In particular, was found to harbor a gene encoding MCR-BG, sharing 84% identity with MCR-9. That gene was neither expressed nor inducible in its original host, which was fully susceptible to polymyxins. This work showed that genes may circulate silently and remain undetected unless induced by colistin.
Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Proteins; Ethanolaminephosphotransferase; Microbial Sensitivity Tests; Plasmids; Polymyxins
PubMed: 31209009
DOI: 10.1128/AAC.00965-19 -
Microbiology Resource Announcements Jul 2019We report here the draft genome sequence of sp. strain A111, isolated on the basis of bioconversion activity of the plant growth-regulating compound 2-azahypoxanthine...
We report here the draft genome sequence of sp. strain A111, isolated on the basis of bioconversion activity of the plant growth-regulating compound 2-azahypoxanthine to 2-aza-8-oxohypoxanthine. The genome contains 4,388 protein-coding sequences, including several genes possibly involved in the metabolism of the plant growth-regulating compound.
PubMed: 31320419
DOI: 10.1128/MRA.00664-19