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Applied Microbiology and Biotechnology Dec 20225-Ketogluconate (5KGA) is a precursor for synthesizing tartrate, a valuable compound used in several industries. In a previous study, Gluconobacter japonicus NBRC 3271...
5-Ketogluconate (5KGA) is a precursor for synthesizing tartrate, a valuable compound used in several industries. In a previous study, Gluconobacter japonicus NBRC 3271 mutant strain D2, which lacks two membranous gluconate 2-dehydrogenases, was shown to produce 5KGA but not 2-ketogluconate from a mixture of glucose and gluconate. In this study, we aimed to develop an efficient 5KGA production system using G. japonicus D2 as the parental strain. D2 produced 5KGA from glucose in a jar fermentor culture; however, 5KGA levels were reduced during the late phase of cultivation. To increase the potential of D2 for 5KGA production, the cytoplasmic metabolism related to the utilization of 5KGA and gluconate was modified; the gno and gntK genes encoding 5KGA reductase and gluconokinase, respectively, were deleted from D2, generating D4. Improved 5KGA production was observed in D4 compared to that in D2, but a significant amount of gluconate remained at the end of cultivation, leading to an unsatisfied yield of 0.83 mol (mol glucose). The conversion of gluconate to 5KGA is catalyzed by pyrroloquinoline quinone (PQQ)-dependent glycerol dehydrogenase (GLDH), which easily forms an apoenzyme by releasing PQQ and calcium ions. Thus, the effects of CaCl addition to the culture medium on 5KGA production by D4 were investigated. We demonstrated that 1 mM CaCl addition positively affected the maintenance of the PQQ-GLDH activity toward gluconate and consequently enhanced 5KGA production, and the yield reached 0.97 mol (mol glucose). KEY POINTS: • An efficient 5KGA production system was developed with Gluconobacter japonicus. • Deleting the gno and gntK genes blocked the catabolism of 5KGA and gluconate. • The addition of 1 mM CaCl efficiently improved the conversion of glucose to 5KGA.
Topics: Calcium Chloride; Gluconobacter; Gluconates; PQQ Cofactor; Glucose
PubMed: 36271931
DOI: 10.1007/s00253-022-12242-0 -
MSphere Aug 2021(formerly TM7) have reduced genomes and a small cell size and appear to have a parasitic lifestyle dependent on a bacterial host. Although there are at least 6 major...
(formerly TM7) have reduced genomes and a small cell size and appear to have a parasitic lifestyle dependent on a bacterial host. Although there are at least 6 major clades of inhabiting the human oral cavity, complete genomes of oral were previously limited to the G1 clade. In this study, nanopore sequencing was used to obtain three complete genome sequences from clade G6. Phylogenetic analysis suggested the presence of at least 3 to 5 distinct species within G6, with two discrete taxa represented by the 3 complete genomes. G6 were highly divergent from the more-well-studied clade G1 and had the smallest genomes and lowest GC content of all . Pangenome analysis showed that although 97% of shared pan- core genes and 89% of G1-specific core genes had putative functions, only 50% of the 244 G6-specific core genes had putative functions, highlighting the novelty of this group. Compared to G1, G6 harbored divergent metabolic pathways. G6 genomes lacked an FF ATPase, the pentose phosphate pathway, and several genes involved in nucleotide metabolism, which were all core genes for G1. G6 genomes were also unique compared to that of G1 in that they encoded d-lactate dehydrogenase, adenylate cyclase, limited glycerolipid metabolism, a homolog to a lipoarabinomannan biosynthesis enzyme, and the means to degrade starch. These differences at key metabolic steps suggest a distinct lifestyle and ecological niche for clade G6, possibly with alternative hosts and/or host dependencies, which would have significant ecological, evolutionary, and likely pathogenic implications. are ultrasmall parasitic bacteria that are common members of the oral microbiota and have been increasingly linked to disease and inflammation. However, the lifestyle and impact on human health of remain poorly understood, especially for the clades with no complete genomes (G2 to G6) or cultured isolates (G2 and G4 to G6). Obtaining complete genomes is of particular importance for , because they lack many of the "essential" core genes used for determining draft genome completeness, and few references exist outside clade G1. In this study, complete genomes of 3 G6 strains, representing two candidate species, were obtained and analyzed. The G6 genomes were highly divergent from that of G1 and enigmatic, with 50% of the G6 core genes having no putative functions. The significant difference in encoded functional pathways is suggestive of a distinct lifestyle and ecological niche, probably with alternative hosts and/or host dependencies, which would have major implications in ecology, evolution, and pathogenesis.
Topics: Acetobacteraceae; Genome, Bacterial; Metabolic Networks and Pathways; Microbiota; Mouth; Phylogeny; Sequence Analysis, DNA
PubMed: 34378983
DOI: 10.1128/mSphere.00530-21 -
Communications Biology Nov 2021The gut microbiome produces vitamins, nutrients, and neurotransmitters, and helps to modulate the host immune system-and also plays a major role in the metabolism of...
The gut microbiome produces vitamins, nutrients, and neurotransmitters, and helps to modulate the host immune system-and also plays a major role in the metabolism of many exogenous compounds, including drugs and chemical toxicants. However, the extent to which specific microbial species or communities modulate hazard upon exposure to chemicals remains largely opaque. Focusing on the effects of collateral dietary exposure to the widely used herbicide atrazine, we applied integrated omics and phenotypic screening to assess the role of the gut microbiome in modulating host resilience in Drosophila melanogaster. Transcriptional and metabolic responses to these compounds are sex-specific and depend strongly on the presence of the commensal microbiome. Sequencing the genomes of all abundant microbes in the fly gut revealed an enzymatic pathway responsible for atrazine detoxification unique to Acetobacter tropicalis. We find that Acetobacter tropicalis alone, in gnotobiotic animals, is sufficient to rescue increased atrazine toxicity to wild-type, conventionally reared levels. This work points toward the derivation of biotic strategies to improve host resilience to environmental chemical exposures, and illustrates the power of integrative omics to identify pathways responsible for adverse health outcomes.
Topics: Acetobacter; Animals; Atrazine; Drosophila melanogaster; Female; Gastrointestinal Microbiome; Host Microbial Interactions; Inactivation, Metabolic; Insecticides; Male
PubMed: 34819611
DOI: 10.1038/s42003-021-02847-y -
Carbohydrate Polymers Feb 2021Biotech nanocellulose (bacterial nanocellulose, BNC) is a high potential natural polymer. Moreover, it is the only cellulose type that can be produced biotechnologically... (Review)
Review
Biotech nanocellulose (bacterial nanocellulose, BNC) is a high potential natural polymer. Moreover, it is the only cellulose type that can be produced biotechnologically using microorganisms resulting in hydrogels with high purity, high mechanical strength and an interconnecting micropore system. Recently, the subject of intensive research is to influence this biosynthesis to create function-determining properties. This review reports on the progress in product design and today's state of technical and medical applications. A novel, dynamic, template-based technology, called Mobile Matrix Reservoir Technology (MMR Tech), is highlighted. Thereby, shape, dimensions, surface properties, and nanonetwork structures can be designed in a process-controlled manner. The formed multilayer materials open up new applications in medicine and technology. Especially medical materials for cardiovascular and visceral surgery, and drug delivery systems are developed. The effective production of layer-structured composites and coatings are important for potential applications in the electronics, paper, food and packaging technologies.
Topics: Acetobacteraceae; Biosensing Techniques; Biotechnology; Cellulose; Drug Delivery Systems; Food Packaging; Gluconacetobacter xylinus; Hydrogels; Nanocomposites; Prostheses and Implants; Tissue Engineering
PubMed: 33357876
DOI: 10.1016/j.carbpol.2020.117313 -
Microbiology Spectrum Oct 2021Insecticide resistance among mosquito species is now a pervasive phenomenon that threatens to jeopardize global malaria vector control efforts. Evidence of links between...
Insecticide resistance among mosquito species is now a pervasive phenomenon that threatens to jeopardize global malaria vector control efforts. Evidence of links between the mosquito microbiota and insecticide resistance is emerging, with significant enrichment of insecticide degrading bacteria and enzymes in resistant populations. Using 16S rRNA amplicon sequencing, we characterized and compared the microbiota of Anopheles coluzzii in relation to their deltamethrin resistance and exposure profiles. Comparisons between 2- and 3-day-old deltamethrin-resistant and -susceptible mosquitoes demonstrated significant differences in microbiota diversity. , , and genera, each of which comprised insecticide-degrading species, were significantly enriched in resistant mosquitoes. Susceptible mosquitoes had a significant reduction in alpha diversity compared to resistant individuals, with and dominating microbial profiles. There was no significant difference in deltamethrin-exposed and -unexposed 5- to 6-day-old individuals, suggesting that insecticide exposure had minimal impact on microbial composition. and were also dominant in 5- to 6-day-old mosquitoes, which had reduced microbial diversity compared to 2- to 3-day-old mosquitoes. Our findings revealed significant alterations of Anopheles coluzzii microbiota associated with deltamethrin resistance, highlighting the potential for identification of novel microbial markers for insecticide resistance surveillance. qPCR detection of and was consistent with 16S rRNA sequencing, suggesting that population-level field screening of bacterial microbiota may be feasibly integrated into wider resistance monitoring, if reliable and reproducible markers associated with phenotype can be identified. Control of insecticide-resistant vector populations remains a significant challenge to global malaria control and while substantial progress has been made elucidating key target site mutations, overexpressed detoxification enzymes and alternate gene families, the contribution of the mosquito microbiota to phenotypic insecticide resistance has been largely overlooked. We focused on determining the effects of deltamethrin resistance intensity on Anopheles coluzzii microbiota and identifying any microbial taxa associated with phenotype. We demonstrated a significant reduction in microbial diversity between deltamethrin-resistant and -susceptible mosquitoes. Insecticide degrading bacterial species belonging to , , and genera were significantly enriched in resistant mosquitoes, while and dominated microbial profiles of susceptible individuals. Our results revealed significant alterations of Anopheles coluzzii microbiota associated with deltamethrin resistance, highlighting the potential for identification of novel microbial markers for surveillance and opportunities for designing innovative control techniques to prevent the further evolution and spread of insecticide resistance.
Topics: Acetobacteraceae; Animals; Anopheles; Cote d'Ivoire; Insecticide Resistance; Insecticides; Malaria; Microbiota; Mosquito Vectors; Nitriles; Pyrethrins; RNA, Ribosomal, 16S; Serratia
PubMed: 34668745
DOI: 10.1128/Spectrum.00157-21 -
Journal of Bioscience and Bioengineering Apr 2022The constituents of fermentation foods vary seasonally and the microbiota plays a crucial role in metabolites formation. Here, the diversity and succession of microbiota...
The constituents of fermentation foods vary seasonally and the microbiota plays a crucial role in metabolites formation. Here, the diversity and succession of microbiota of Shanxi mature vinegar produced with solid-solid fermentation craft have been investigated by Illumina Hiseq sequencing in both summer and winter. Obvious differences were observed in the structure of microbiota between summer and winter, and the bacterial community showed a significant difference (P < 0.05). Alpha diversity analysis showed that the diversity and richness of bacterial community were basically higher than that of fungal community in both summer and winter. For bacterial community, Lactobacillus and Limosilactobacillus were the two major group bacteria in the fermentation process of Shanxi mature vinegar in summer, and they dominated in acetic acid fermentation and alcoholic fermentation stages, respectively. Lactobacillus and Acetobacter were the two major group bacteria during the fermentation of Shanxi mature vinegar in winter. Saccharomyces, Saccharomycopsis, and Issatchenkia were the main yeasts in both seasons, while the dominant mould was Rhizopus in summer and Monascus in winter, respectively. The diversity of yeasts and moulds in winter was far greater than that in summer, especially in alcoholic fermentation stage. Collectively, our work revealed critical insights into effect of seasonal variation on the structure of microbiota of Shanxi mature vinegar, and was relevant in understanding the relationships between environmental change and microbiota.
Topics: Acetic Acid; Acetobacter; Fermentation; Microbiota; Seasons
PubMed: 35125299
DOI: 10.1016/j.jbiosc.2022.01.003 -
PLoS Biology Oct 2019Imaging dense and diverse microbial communities has broad applications in basic microbiology and medicine, but remains a grand challenge due to the fact that many...
Imaging dense and diverse microbial communities has broad applications in basic microbiology and medicine, but remains a grand challenge due to the fact that many species adopt similar morphologies. While prior studies have relied on techniques involving spectral labeling, we have developed an expansion microscopy method (μExM) in which bacterial cells are physically expanded prior to imaging. We find that expansion patterns depend on the structural and mechanical properties of the cell wall, which vary across species and conditions. We use this phenomenon as a quantitative and sensitive phenotypic imaging contrast orthogonal to spectral separation to resolve bacterial cells of different species or in distinct physiological states. Focusing on host-microbe interactions that are difficult to quantify through fluorescence alone, we demonstrate the ability of μExM to distinguish species through an in vitro defined community of human gut commensals and in vivo imaging of a model gut microbiota, and to sensitively detect cell-envelope damage caused by antibiotics or previously unrecognized cell-to-cell phenotypic heterogeneity among pathogenic bacteria as they infect macrophages.
Topics: Acetobacter; Acidaminococcus; Animals; Anti-Bacterial Agents; Cell Wall; Drosophila melanogaster; Escherichia coli; Gastrointestinal Microbiome; Humans; Hydrolysis; Lactobacillus plantarum; Mice; Microscopy; Muramidase; Platyhelminths; RAW 264.7 Cells; Stress, Mechanical; Symbiosis; Vancomycin
PubMed: 31622337
DOI: 10.1371/journal.pbio.3000268 -
International Journal of Systematic and... Feb 2021As part of a study investigating the microbiome of bee hives and honey, two novel strains (TMW 2.1880 and TMW 2.1889) of acetic acid bacteria were isolated and...
As part of a study investigating the microbiome of bee hives and honey, two novel strains (TMW 2.1880 and TMW 2.1889) of acetic acid bacteria were isolated and subsequently taxonomically characterized by a polyphasic approach, which revealed that they cannot be assigned to known species. The isolates are Gram-stain-negative, aerobic, pellicle-forming, catalase-positive and oxidase-negative. Cells of TMW 2.1880 are non-motile, thin/short rods, and cells of TMW 2.1889 are motile and occur as rods and long filaments. Morphological, physiological and phylogenetic analyses revealed a distinct lineage within the genus . Strain TMW 2.1880 is most closely related to the type strain of with a 16S rRNA gene sequence similarity of 99.5 %, and ANIb and DDH values of 94.16 and 56.3 %, respectively. The genome of TMW 2.1880 has a size of 1.98 Mb and a G+C content of 55.3 mol%. Strain TMW 2.1889 is most closely related to the type strain of with a 16S rRNA gene sequence similarity of 99.5 %, and ANIb and DDH values of 85.12 and 29.5 %, respectively. The genome of TMW 2.1889 has a size of 2.07 Mb and a G+C content of 60.4 mol%. Ubiquinone analysis revealed that both strains contained Q-10 as the main respiratory quinone. Major fatty acids for both strains were C, C cyclo 8 and summed feature 8, respectively, and additionally C 2-OH only for TMW 2.1880 and C only for TMW 2.1889. Based on polyphasic evidence, the two isolates from honeycombs of represent two novel species of the genus , for which the names sp. nov and sp. nov. are proposed. The designated respective type strains are TMW 2.1880 (=LMG 31882=CECT 30114) and TMW 2.1889 (=LMG 31883=CECT 30113).
Topics: Acetobacteraceae; Animals; Bacterial Typing Techniques; Base Composition; Bees; DNA, Bacterial; Fatty Acids; Germany; Honey; Nucleic Acid Hybridization; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Ubiquinone
PubMed: 33439113
DOI: 10.1099/ijsem.0.004633 -
International Journal of Biological... Jul 2021In this study, a water-soluble bacterial cellulose sulfate (BCS) was prepared with sulfur trioxide pyridine complex (SO3· Py) in a lithium...
In this study, a water-soluble bacterial cellulose sulfate (BCS) was prepared with sulfur trioxide pyridine complex (SO3· Py) in a lithium chloride (LiCl)/dimethylacetamide (DMAc) homogeneous solution system using bacterial cellulose (BC). The structural study showed that the value for the degrees of substitution of BCS was 1.23. After modification, the C-6 hydroxyl group of BC was completely substituted and the C-2 and C-3 hydroxyl groups were partially substituted. In an aqueous solution, the BCS existed as a linear polymer with irregular coil conformation, which was consistent with the findings observed using atomic force microscopy. The steady-state shear flow and dynamic viscoelasticity were systematically determined over a range of BCS concentrations (1 %-4 %, w/v) and temperature (5 °C-50 °C). Steady-state flow experiments revealed that BCS exhibited shear thinning behavior, which increased with an increase in concentration and a decrease in temperature. These observations were quantitatively demonstrated using the cross model. Moreover, based on the dynamical viscoelastic properties, we confirmed that BCS was a temperature-sensitive and weak elastic gel, which was somewhere between a dilute solution and an elastic gel. Therefore, considering the special synthetic strategy and rheological behavior, BCS might be used as a renewable material in the field of biological tissue engineering, especially in the manufacture of injectable hydrogels, cell scaffolds, and as a drug carrier.
Topics: Carbohydrate Conformation; Cellulose; Drug Carriers; Elasticity; Gels; Gluconacetobacter xylinus; Rheology; Temperature; Tissue Scaffolds; Viscosity
PubMed: 34089760
DOI: 10.1016/j.ijbiomac.2021.06.001 -
Journal of Chemical Ecology Aug 2020The olfactory cues used by various animals to detect and identify food items often include volatile organic compounds (VOCs) produced by food-associated microorganisms....
The olfactory cues used by various animals to detect and identify food items often include volatile organic compounds (VOCs) produced by food-associated microorganisms. Microbial VOCs have potential as lures to trap animal pests, including insect crop pests. This study investigated microorganisms whose VOCs are attractive to natural populations of the spotted wing drosophila (SWD), an invasive insect pest of ripening fruits. The microorganisms readily cultured from wild SWD and SWD-infested fruits included yeasts, especially Hanseniaspora species, and various bacteria, including Proteobacteria (especially Acetobacteraceae and Enterobacteriaceae) and Actinobacteria. Traps in a raspberry planting that were baited with cultures of Hanseniaspora uvarum, H. opuntiae and the commercial lure Scentry trapped relatively high numbers of both SWD and non-target drosophilids. The VOCs associated with these baits were dominated by ethyl acetate and, for yeasts, other esters. By contrast, Gluconobacter species (Acetobacteraceae), whose VOCs were dominated by acetic acid and acetoin and lacked detectable ethyl acetate, trapped 60-75% fewer SWD but with very high selectivity for SWD. VOCs of two other taxa tested, the yeast Pichia sp. and Curtobacterium sp. (Actinobacteria), trapped very few SWD or other insects. Our demonstration of among-microbial variation in VOCs and their attractiveness to SWD and non-pest insects under field conditions provides the basis for improved design of lures for SWD management. Further research is required to establish how different microbial VOC profiles may function as reliable cues of habitat suitability for fly feeding and oviposition, and how this variation maps onto among-insect species differences in habitat preference.
Topics: Actinobacteria; Animals; Cues; Drosophila; Female; Hanseniaspora; Male; Olfactory Perception; Proteobacteria; Random Allocation; Volatile Organic Compounds
PubMed: 31879864
DOI: 10.1007/s10886-019-01139-4