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Multilamellar and Multivesicular Outer Membrane Vesicles Produced by a Buttiauxella agrestis Mutant.Applied and Environmental Microbiology Oct 2020Outer membrane vesicles (OMVs) are naturally released from Gram-negative bacteria and play important roles in various biological functions. Released vesicles are not...
Outer membrane vesicles (OMVs) are naturally released from Gram-negative bacteria and play important roles in various biological functions. Released vesicles are not uniform in shape, size, or characteristics, and little is known about this diversity of OMVs. Here, we show that deletion of , which encodes a part of the Tol-Pal system, leads to the production of multiple types of vesicles and increases overall vesicle production in the high-vesicle-forming type strain JCM 1090. The Δ mutant produced small OMVs and multilamellar/multivesicular OMVs (M-OMVs) as well as vesicles with a striking similarity to the wild type. M-OMVs, previously undescribed, contained triple-lamellar membrane vesicles and multiple vesicle-incorporating vesicles. Ultracentrifugation enabled the separation and purification of each type of OMV released from the Δ mutant, and visualization by quick-freeze deep-etch and replica electron microscopy indicated that M-OMVs are composed of several lamellar membranes. Visualization of intracellular compartments of Δ mutant cells showed that vesicles were accumulated in the broad periplasm, which is probably due to the low linkage between the outer and inner membranes attributed to the Tol-Pal defect. The outer membrane was invaginating inward by wrapping a vesicle, and the precursor of M-OMVs existed in the cell. Thus, we demonstrated a novel type of bacterial OMV and showed that unconventional processes enable the Δ mutant to form unique vesicles. Membrane vesicle (MV) formation has been recognized as a common mechanism in prokaryotes, and MVs play critical roles in intercellular interaction. However, a broad range of MV types and their multiple production processes make it difficult to gain a comprehensive understanding of MVs. In this work, using vesicle separation and electron microscopic analyses, we demonstrated that diverse types of outer membrane vesicles (OMVs) were released from an engineered strain, JCM 1090 Δ mutant. We also discovered a previously undiscovered type of vesicle, multilamellar/multivesicular outer membrane vesicles (M-OMVs), which were released by this mutant using unconventional processes. These findings have facilitated considerable progress in understanding MV diversity and expanding the utility of MVs in biotechnological applications.
Topics: Bacterial Proteins; Enterobacteriaceae; Mutation; Periplasmic Proteins
PubMed: 32801184
DOI: 10.1128/AEM.01131-20 -
Frontiers in Veterinary Science 2021The gut microbiota contributes to host health by maintaining homeostasis and improving digestive efficiency. Therefore, identifying gut microbes will shed light on the...
The gut microbiota contributes to host health by maintaining homeostasis and improving digestive efficiency. Therefore, identifying gut microbes will shed light on the annual life cycle of animals and in particular those that are threatened or endangered. Nonetheless, the gut microbial composition of the majority of bird species is still unknown. Here, for the first time, 16S rRNA gene sequencing was used to characterize and compare the community composition and diversity of gut microbiotas from six species of birds raised at the Wildlife Conservation Center in Baotou, China: relict gull (; = 3), muscovy duck (; = 3), ruddy shelduck (; = 3), demoiselle crane (; = 4), whooper swan (; = 3), and black swan (; = 5). A total of 26,616 operational taxonomic units from 21 samples were classified into 32 phyla and 507 genera. Chao1, Shannon diversity, observed species, and Simpson index analysis revealed differences in the community richness and diversity between the different species. Proteobacteria was the dominant bacterial phylum in whooper swan and relict gull, whereas Firmicutes was the dominant bacterial phylum in the other species. At the genus level, 11 dominant genera were detected (, and ). Principal component and cluster analyses revealed that, while the microbial community composition of different individuals of the same species clustered together, the gut microbial composition varied between the bird species. Furthermore, the most abundant bacterial species differed between bird species. Because many avian gut microbes are derived from the diet, the eating habits and natural living environment of birds may be important contributing factors to the observed differences. Short-term changes to the diet and living environment have little effect on the composition of the avian gut microbiota. This study provides a theoretical basis for bird protection, including disease prevention and control.
PubMed: 34957285
DOI: 10.3389/fvets.2021.791287 -
Poultry Science Oct 2019Adequate dietary Ca and available phosphorus (avP) are essential to long-term egg production and bone health in laying hens. The effects of dietary Ca and avP levels and...
Adequate dietary Ca and available phosphorus (avP) are essential to long-term egg production and bone health in laying hens. The effects of dietary Ca and avP levels and Buttiauxella sp. phytase (BSP) were studied in Lohmann LSL Lite hens from 30 to 70 wk of age (woa). Hens (n = 456; 4 per cage) were fed either a primary breeder recommendation-based diet (positive control; PC); the PC with avP and Ca levels reduced by 0.146 and 0.134% of the diet, respectively, without (NC) or with 300 FTU/kg BSP (NC+BSP). Egg production, BW, feed intake, FCR, and eggshell quality from 30 to 70 woa, and apparent ileal digestibility of P (AIDP) and Ca (AIDCa), and bone quality at 32, 48, and 70 woa were measured. The avP and Ca levels in the NC diet were not clinically deficient, as most parameters were unaffected by diet. Hen BW from 34 to 70 woa tended to be 2.9% greater (P = 0.076) for PC and NC+BSP compared to NC. Mid-diaphysis cortical bone mineral content (CBMC) tended to be 10% and 9% higher (P = 0.065) in the NC+BSP hens than in NC hens at 48 and 70 woa, respectively. AIDP of NC+BSP was 24% greater (P = 0.034) than of NC at 32 woa and tended to be 18% greater (P = 0.082) than AIDP of PC at 48 woa, and 25% lower than of NC and PC at 70 woa (P = 0.028). AIDCa was 25% lower for NC+BSP than PC at 48 woa only (P = 0.037). The avP and Ca sufficiency in the NC diet limited the opportunity to determine a phytase effect. Although the supplemental BSP tended to increase BW and 48 and 70 woa CBMC, and increased 32 woa AIDP, the efficacy of BSP could not be determined due to the lack of an NC effect on most parameters. Commercial laying hens can maintain health and productivity at lower than recommended levels of dietary Ca and avP; phytase supplementation may allow for even further reductions.
Topics: 6-Phytase; Animal Feed; Animals; Bone and Bones; Calcium; Chickens; Diet; Dietary Supplements; Digestion; Egg Shell; Enterobacteriaceae; Female; Ileum; Phosphorus
PubMed: 31032860
DOI: 10.3382/ps/pez220 -
Journal of Animal Science May 2019This study evaluated the effects of increasing the dose of a 6-phytase from Buttiauxella on phytate degradation, mineral, energy, and AA digestibility in weaned pigs fed...
Increasing the dosing of a Buttiauxella phytase improves phytate degradation, mineral, energy, and amino acid digestibility in weaned pigs fed a complex diet based on wheat, corn, soybean meal, barley, and rapeseed meal1.
This study evaluated the effects of increasing the dose of a 6-phytase from Buttiauxella on phytate degradation, mineral, energy, and AA digestibility in weaned pigs fed complex diets based on wheat, corn, soybean meal, barley, and rapeseed meal. A negative control (NC) diet containing no added inorganic phosphorus (P) and a reduction of 0.1% calcium (Ca) and 36 kcal/kg ME was supplemented with Buttiauxella phytase at 0, 250, 500, 1,000, or 2,000 FTU/kg diet and tested against a nutritionally adequate, positive control (PC) diet. One phytase units (FTU) is the amount of enzyme that liberates 1 micromole of inorganic phosphate per minute from a sodium phytate substrate at pH 5.5 and 37 °C. Barrows (Topigs × Pietrian; initial mean body weight 19.3 kg) were housed individually in metabolic crates and fed the test diets in mash form via 2 equal meals per day for 9 d (fed at 2.5 times the maintenance energy requirement), with 8 replicate pigs per treatment, in 2 experimental runs (total n = 48). After a 3-d adaptation period, urine and feces were collected over 5 d for measurements of apparent total tract digestibility (ATTD) and retention of nutrients. On day 9, pigs were euthanized and ileal digesta collected for measurements of apparent ileal digestibility (AID) of nutrients. Phytase improved (P < 0.05) digestibility of all measured AA except Trp (P < 0.1), and AID P, nitrogen, phytate, ATTD P, Ca versus NC. Increasing phytase dose from 0 (NC) to 2,000 FTU/kg increased AID Lys, Cys, Thr, Val, Ile, Leu, mean AA, P, N, phytate, ATTD P, N, Na, energy, ME, P retention (g/d), and reduced P excretion (g/d) in a linear or exponential manner (P < 0.05). Phytase at 2,000 FTU/kg improved AA digestibility by between +3.1 percentage points (Trp) and +8.8 percentage points (Cys) versus NC (average +6.3 percentage points) (P < 0.05). Phytase inclusion at 2,000 FTU/kg reduced P excretion (g/d) by 57% versus PC (P < 0.05). In conclusion, increasing Buttiauxella phytase in the range of 0 to 2,000 FTU/kg increased phytate degradation, improved AA and P digestibility, and reduced P excretion in weaned pigs fed complex diets.
Topics: 6-Phytase; Amino Acids; Animal Feed; Animals; Brassica rapa; Calcium, Dietary; Diet; Dietary Supplements; Digestion; Enterobacteriaceae; Feces; Gastrointestinal Tract; Hordeum; Minerals; Phytic Acid; Glycine max; Swine; Triticum; Zea mays
PubMed: 31056701
DOI: 10.1093/jas/skz151 -
Microbiological Research Jul 2021The association of different species of endophytic bacteria with the rhizosphere of the host plants can stimulate growth, development and acclimatization, offering a...
The association of different species of endophytic bacteria with the rhizosphere of the host plants can stimulate growth, development and acclimatization, offering a greater quantity of seedlings, in addition to reducing the cycle, providing economic return to the producer. The objective of this study was to evaluate the effect of introduction four bacterial isolates through inoculation into the root system in three banana cultivars (Prata Anã, Grande Naine and BRS Princesa) in the acclimatization phase. The evaluated treatments were: control (nutrient broth without bacteria); Bacillus cereus strain 1 (BC1); Bacillus cereus strain 2 (BC2); Bacillus thuringiensis (BT); Buttiauxella agrestis (BA). The morphological characteristics related to the development of the plants (total height and pseudostem diameter) were evaluated throughout the acclimatization period. After 90 days of transplanting and acclimatization, root length, leaf number, dry root weight, pseudostem and leaf, leaf area, internal carbon concentration, stomatal conductance, photosynthesis rate, transpiration rate, leaf temperature and chlorophyll were evaluated. The bacteria showed different results in relation to the studied cultivars. Considering the morphological and physiological characteristics observed in this study, B. thuringiensis for the cultivars Prata Anã and Grande Naine and the B. agrestis for the cultivar BRS Princesa are recommended for the process of acclimatization of banana seedlings, as they stimulated growth of the plant, increasing the dry mass, besides promoting the growth of roots. In this way, they improved the physiological aspects of the plants and reduced the period of acclimatization of the banana.
Topics: Adaptation, Physiological; Agricultural Inoculants; Bacillus; Chlorophyll; Endophytes; Enterobacteriaceae; Musa; Photosynthesis; Plant Roots; Seedlings
PubMed: 33765636
DOI: 10.1016/j.micres.2021.126750 -
Animal Nutrition (Zhongguo Xu Mu Shou... Dec 2018The objective of this study was to test if a novel phytase from sp. can replace all added inorganic phosphate in a diet with reduced Ca and metabolizable energy (ME)...
The objective of this study was to test if a novel phytase from sp. can replace all added inorganic phosphate in a diet with reduced Ca and metabolizable energy (ME) fed to commercial pigs from 12 kg body weight (BW) until slaughter, whilst maintaining performance and carcass quality parameters. Four dietary treatments were tested in a completely randomized design with 9 replicate pens, each containing 31 mixed sex Newsham Choice pigs. Diets included a positive control (PC) based on corn, soybean meal, wheat middling and bakery meal, meeting all nutrient requirement of pigs; a negative control (NC) excluded inorganic phosphate and with reduced Ca (-0.13%) and ME (-0.15 MJ/kg); and NC supplemented with phytase at 500 or 1,000 FTU/kg feed. Diets were fed in mash form in 5 phases: starter (12 to 25 kg BW), grower 1 (25 to 50 kg BW) and 2 (50 to 75 kg BW), and finisher 1 (75 to 100 kg BW) and 2 (100 kg BW to slaughter). The NC group showed lower ( < 0.05) average daily feed intake (ADFI) and average daily gain (ADG) in starter and grower phases, lower gain to feed ratio (G:F) in starter and grower 1 compared with PC. Pigs receiving the high dose of phytase of 1,000 FTU/kg had improved performance vs. the 500 FTU/kg phytase treatment in starter and grower 1 phase compared with the PC in grower 1 phase. Increasing phytase dose resulted in a linear increase in ADG (12 to 120 kg BW) and G:F (50 to 75 kg BW). A comparison of treatment groups over the full production period from 12 kg BW until slaughter showed that both 500 and 1,000 FTU/kg phytase treatments were able to maintain growth performance and carcass characteristics compared with PC. The application of phytase could therefore be used as an effective strategy to replace all inorganic phosphate in diets of pigs fed corn, soybean meal, wheat middling and bakery meal based diets from 12 kg BW. An economic analysis showed greater return from both phytase treatments vs. the PC and favored the higher phytase dose at 1,000 FTU/kg vs. the traditional dose of 500 FTU/kg. The latter was mainly related to the improved performance of the higher dose in younger pigs to 75 kg BW.
PubMed: 30564754
DOI: 10.1016/j.aninu.2018.02.002 -
Microbiology Resource Announcements Mar 2022We report the draft genome sequences of spp. strains that were isolated from water and gastropods. Three isolates show fluorescence in the Colilert system, indicating...
We report the draft genome sequences of spp. strains that were isolated from water and gastropods. Three isolates show fluorescence in the Colilert system, indicating unusual β-d-glucuronidase activity, and phylogenetic analyses suggest that they represent a novel species. Another strain, without β-d-glucuronidase activity, was assigned to the species Buttiauxella ferragutiae.
PubMed: 35234507
DOI: 10.1128/mra.00064-22 -
Microbiology Resource Announcements May 2021We report here the complete genome sequence of DSM 9389, which harbors eight 16S rRNA genes classified into three types. The genome sequence of this strain showed a...
We report here the complete genome sequence of DSM 9389, which harbors eight 16S rRNA genes classified into three types. The genome sequence of this strain showed a high average nucleotide identity (97.3%) with that of the highly membrane vesicle-producing strain ATCC 33320.
PubMed: 33986092
DOI: 10.1128/MRA.00301-21 -
Molecules (Basel, Switzerland) Feb 20232,4,6-Trinitrotoluene (TNT) is an aromatic pollutant that is difficult to be degraded in the natural environment. The screening of efficient degrading bacteria for...
2,4,6-Trinitrotoluene (TNT) is an aromatic pollutant that is difficult to be degraded in the natural environment. The screening of efficient degrading bacteria for bioremediation of TNT has received much attention from scholars. In this paper, transcriptome analysis of the efficient degrading bacterium sp. S19-1 revealed that the monooxygenase gene () was significantly up-regulated during TNT degradation. S-Δ (absence of gene in S19-1 mutant) degraded TNT 1.66-fold less efficiently than strain S19-1 (from 71.2% to 42.9%), and E- mutant (-expressing strain) increased the efficiency of TNT degradation 1.33-fold (from 52.1% to 69.5%) for 9 h at 180 rpm at 27 °C in LB medium with 1.4 µg·mL TNT. We predicted the structure of BuMO and purified recombinant BuMO (rBuMO). Its specific activity was 1.81 µmol·min·mg protein at pH 7.5 and 35 °C. The results of gas chromatography mass spectrometry (GC-MS) analysis indicated that 4-amino-2,6-dinitrotoluene (ADNT) is a metabolite of TNT biodegradation. We speculate that MO is involved in catalysis in the bacterial degradation pathway of TNT in TNT-polluted environment.
Topics: Biodegradation, Environmental; Trinitrotoluene; Mixed Function Oxygenases; Escherichia coli
PubMed: 36838956
DOI: 10.3390/molecules28041969 -
Frontiers in Microbiology 2021Whether terrestrial life can withstand the martian environment is of paramount interest for planetary protection measures and space exploration. To understand microbial...
Whether terrestrial life can withstand the martian environment is of paramount interest for planetary protection measures and space exploration. To understand microbial survival potential in Mars-like conditions, several fungal and bacterial samples were launched in September 2019 on a large NASA scientific balloon flight to the middle stratosphere (∼38 km altitude) where radiation levels resembled values at the equatorial Mars surface. Fungal spores of and bacterial cells of , subsp. , and sp. MASE-IM-9 were launched inside the MARSBOx (Microbes in Atmosphere for Radiation, Survival, and Biological Outcomes Experiment) payload filled with an artificial martian atmosphere and pressure throughout the mission profile. The dried microorganisms were either exposed to full UV-VIS radiation (UV dose = 1148 kJ m) or were shielded from radiation. After the 5-h stratospheric exposure, samples were assayed for survival and metabolic changes. Spores from the fungus and cells from the Gram-(-) bacterium were the most resistant with a 2- and 4-log reduction, respectively. Exposed sp. MASE-IM-9 was completely inactivated (both with and without UV exposure) and subsp. only survived the UV shielded experimental condition (3-log reduction). Our results underscore a wide variation in survival phenotypes of spacecraft associated microorganisms and support the hypothesis that pigmented fungi may be resistant to the martian surface if inadvertently delivered by spacecraft missions.
PubMed: 33692763
DOI: 10.3389/fmicb.2021.601713