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Carbohydrate Polymers Jan 2024Levans of different structures and molecular weights (MW) can display various techno-functional and health-promoting properties. In the present study, selected levans...
Characterization of levans produced by levansucrases from Bacillus amyloliquefaciens and Gluconobacter oxydans: Structural, techno-functional, and anti-inflammatory properties.
Levans of different structures and molecular weights (MW) can display various techno-functional and health-promoting properties. In the present study, selected levans were produced by the transfructosylation of sucrose catalyzed by levansucrases from Bacillus amyloliquefaciens and Gluconobacter oxydans, and their structural, techno-functional and anti-inflammatory properties were investigated. NMR and methylation/GC analysis confirmed the structure of β-(2, 6) levans. The structural characterization led to the classification of levans as high MW (HMW, ≥100 kDa), low MW (LMW, ≤20 kDa) and mix L/HMW ones. Levan with higher MW had more linear fructosyl units with fewer reducing ends and branching residues. LMW levan showed the highest foaming capacity and stability while HMW levan had the highest emulsion stability. HMW and mix L/HMW levans showed comparable water and oil-holding capacities, which were higher than LMW. HMW and mix L/HMW levans were found to have gelling properties at low concentrations. The rheological behaviour of HMW levan-based gel was a more viscous-like gel, while that of mix L/HMW levan-based one showed more elastic solid like-gel. The temperature also influenced the rheology of levan, showing that the mix L/HMW levan gel network was the most thermal stable as its viscoelasticity remained constant at the highest temperature (75 °C). Studies on the biological activity of levans of HMW and LMW revealed in-vitro anti-inflammatory properties as they significantly reduced the production of LPS-triggered pro-inflammatory cytokines in differentiated Caco-2 cells.
Topics: Humans; Gluconobacter oxydans; Bacillus amyloliquefaciens; Caco-2 Cells; Fructans; Anti-Inflammatory Agents
PubMed: 37940238
DOI: 10.1016/j.carbpol.2023.121332 -
Preparative Biochemistry & Biotechnology May 2024The current study intended to analyze the impact of ethanol and lactic acid on the bacterial cellulose yield as well as physicochemical and mechanical properties, by...
The current study intended to analyze the impact of ethanol and lactic acid on the bacterial cellulose yield as well as physicochemical and mechanical properties, by using . The optimization of ethanol and lactic acid concentration has been done by using one-way ANOVA. Both the supplements significantly enhance the yield of bacterial cellulose (BC) as compared to the standard Hestrin-Schramm medium (control). Optimization leads to significant increase in BC yield as compared to the control, i.e., the addition, of optimized concentration of lactic acid (0.6%) increases the yield from (0.78 ± 0.026) g to (4.89 ± 0.020) g dry weight, and optimized concentration of ethanol (1%) increases the yield from (0.73 ± 0.057) g to (3.7 ± 0.01) g dry weight. Various physicochemical and mechanical properties of BC films produced in different media (i.e., HS, HS + Ethanol, and HS + Lactic acid), such as the crystallinity, structure, tensile strength, strain at break, Young's modulus, and water holding capacity, were also examined, by employing various techniques such as SEM, FTIR, XRD, etc. BC produced in medium supplemented with the optimum concentration of both the additives were found to possesses higher porosity. Though, slight decline in crystallinity was observed. But the tensile strength and strain at break, were upgraded 1.5-2.5 times, 2-2.5 times, respectively. This article attempted to present a method for enhancing BC yields and characteristics that may lead to more widespread and cost-effective use of this biopolymer.
Topics: Cellulose; Ethanol; Lactic Acid; Gluconacetobacter; Tensile Strength; Fermentation; Culture Media
PubMed: 37937534
DOI: 10.1080/10826068.2023.2276188 -
Journal of Applied Microbiology Nov 2023This study aimed to investigate the probiotic effects of Acetobacter pasteurianus BP2201, isolated from brewing mass, for the treatment of alcohol-induced learning and...
AIMS
This study aimed to investigate the probiotic effects of Acetobacter pasteurianus BP2201, isolated from brewing mass, for the treatment of alcohol-induced learning and memory ability impairments in a Caenorhabditis elegans model.
METHODS AND RESULTS
Acetobacter pasteurianus BP2201 was examined for probiotic properties, including acid and bile salt resistance, ethanol degradation, antioxidant efficacy, hemolytic activity, and susceptibility to antibiotics. The strain displayed robust acid and bile salt tolerance, efficient ethanol degradation, potent antioxidant activity, and susceptibility to specific antibiotics. Additionally, in the C. elegans model, administering A. pasteurianus BP2201 significantly improved alcohol-induced learning and memory impairments.
CONCLUSIONS
Acetobacter pasteurianus BP2201 proves to be a promising candidate strain for the treatment of learning and memory impairments induced by alcohol intake.
Topics: Animals; Caenorhabditis elegans; Acetic Acid; Acetobacter; Antioxidants; Ethanol; Anti-Bacterial Agents
PubMed: 37934610
DOI: 10.1093/jambio/lxad253 -
International Journal of Systematic and... Nov 2023is the hemipteran pest and vector of a devastating bacterial pathogen of citrus worldwide. In addition to the two core bacterial endosymbionts of , Carsonella ruddii...
is the hemipteran pest and vector of a devastating bacterial pathogen of citrus worldwide. In addition to the two core bacterial endosymbionts of , Carsonella ruddii and Profftella armatura, the genome of a novel endosymbiont and as of yet undescribed microbe was discovered in a Hawaiian population through deep sequencing of multiple populations. Found to be closely related to the genus in the family by 16S rRNA gene sequence analysis, it forms a sister clade along with other insect-associated 16S rRNA gene sequences from uncultured bacterium found associated with and . Multilocus sequence analysis confirmed the phylogenetic placement sister to the clade. Despite the culturable clade being the closest phylogenetic neighbour, attempts to culture this newly identified bacterial endosymbiont were unsuccessful. On the basis of these distinct genetic differences, the novel endosymbiont is proposed to be classified into a candidate genus and species ' Kirkpatrickella diaphorinae'. The full genome was deposited in GenBank (accession number CP107052; prokaryotic 16S rRNA OP600170).
Topics: Animals; Symbiosis; Hawaii; RNA, Ribosomal, 16S; Phylogeny; DNA, Bacterial; Sequence Analysis, DNA; Bacterial Typing Techniques; Base Composition; Fatty Acids; Bacteria; Hemiptera; Citrus
PubMed: 37930120
DOI: 10.1099/ijsem.0.006111 -
Journal of Bacteriology Nov 2023, an industrial vinegar-producing strain, is suffered by fermentation stress such as fermentation heat and/or high concentrations of acetic acid. By an experimental...
, an industrial vinegar-producing strain, is suffered by fermentation stress such as fermentation heat and/or high concentrations of acetic acid. By an experimental evolution approach, we have obtained a stress-tolerant strain, exhibiting significantly increased growth and acetic acid fermentation ability at higher temperatures. In this study, we report that only the three gene mutations of ones accumulated during the adaptation process, , , and , were sufficient to reproduce the increased thermotolerance of . These mutations resulted in cell envelope modification, including increased phospholipid and lipopolysaccharide synthesis, increased respiratory activity, and cell size reduction. The phenotypic changes may cooperatively work to make the adapted cell thermotolerant by enhancing cell surface integrity, nutrient or oxygen availability, and energy generation.
Topics: Acetic Acid; Thermotolerance; Acetobacter; Fermentation; Amino Acids
PubMed: 37930061
DOI: 10.1128/jb.00101-23 -
Frontiers in Microbiology 2023Spontaneous fermentation of raw cow milk without backslopping is in practice worldwide as part of the traditional food culture, including "" preparation in earthen pots...
INTRODUCTION
Spontaneous fermentation of raw cow milk without backslopping is in practice worldwide as part of the traditional food culture, including "" preparation in earthen pots in Northeast India, "" of Niger and "" of Benin prepared in calabash vessels in West Africa. Very few reports are available about the differences in bacterial communities that evolved during the spontaneous mesophilic fermentation of cow milk in diverse geographical regions.
METHODS
In this study, we used high throughput amplicon sequencing of bacterial 16S rRNA gene to investigate 44 samples of naturally fermented homemade milk products and compared the bacterial community structure of these foods, which are widely consumed in Northeast India and Western Africa.
RESULTS AND DISCUSSION
The spontaneous milk fermentation shared the lactic acid bacteria, mainly belonging to and in these two geographically isolated regions. Indian samples showed a high bacterial diversity with the predominance of and , whereas was abundant in the West African samples. However, the cheese of Benin, prepared by curdling the milk with proteolytic leaf extract of followed by natural fermentation, contained spp.) as the dominant bacteria. Our analysis also detected several potential pathogens, like an emerging infectious foodborne pathogen in samples, an uncultured bacterium of in and samples, and spp. in the samples of Northeast India. These findings will allow us to develop strategies to address the safety issues related to spontaneous milk fermentation and implement technological interventions for controlled milk fermentation by designing starter culture consortiums for the sustainable production of uniform quality products with desirable functional and organoleptic properties.
PubMed: 37886068
DOI: 10.3389/fmicb.2023.1166518 -
PloS One 2023Lactobacilli and Acetobacter sp. are commercially important bacteria that often form communities in natural fermentations, including food preparations, spoilage, and in...
Lactobacilli and Acetobacter sp. are commercially important bacteria that often form communities in natural fermentations, including food preparations, spoilage, and in the digestive tract of the fruit fly Drosophila melanogaster. Communities of these bacteria are widespread and prolific, despite numerous strain-specific auxotrophies, suggesting they have evolved nutrient interdependencies that regulate their growth. The use of a chemically-defined medium (CDM) supporting the growth of both groups of bacteria would facilitate the identification of the molecular mechanisms for the metabolic interactions between them. While numerous CDMs have been developed that support specific strains of lactobacilli or Acetobacter, there has not been a medium formulated to support both genera. We developed such a medium, based on a previous CDM designed for growth of lactobacilli, by modifying the nutrient abundances to improve growth yield. We further simplified the medium by substituting casamino acids in place of individual amino acids and the standard Wolfe's vitamins and mineral stocks in place of individual vitamins and minerals, resulting in a reduction from 40 to 8 stock solutions. These stock solutions can be used to prepare several CDM formulations that support robust growth of numerous lactobacilli and Acetobacters. Here, we provide the composition and several examples of its use, which is important for tractability in dissecting the genetic and metabolic basis of natural bacterial species interactions.
Topics: Animals; Acetobacter; Lactobacillus; Drosophila melanogaster; Bacteria; Vitamins
PubMed: 37824485
DOI: 10.1371/journal.pone.0292585 -
Applied and Environmental Microbiology Oct 2023Gut microbiota are fundamentally important for healthy function in animal hosts. is a powerful system for understanding host-microbiota interactions, with modulation of...
Gut microbiota are fundamentally important for healthy function in animal hosts. is a powerful system for understanding host-microbiota interactions, with modulation of the microbiota inducing phenotypic changes that are conserved across animal taxa. Qualitative differences in diet, such as preservatives and dietary yeast batch variation, may affect fly health indirectly via microbiota, and may potentially have hitherto uncharacterized effects directly on the fly. These factors are rarely considered, controlled, and are not standardized among laboratories. Here, we show that the microbiota's impact on fly triacylglyceride (TAG) levels-a commonly-measured metabolic index-depends on both preservatives and yeast, and combinatorial interactions among the three variables. In studies of conventional, axenic, and gnotobiotic flies, we found that microbial impacts were apparent only on specific yeast-by-preservative conditions, with TAG levels determined by a tripartite interaction of the three experimental factors. When comparing axenic and conventional flies, we found that preservatives caused more variance in host TAG than microbiota status, and certain yeast-preservative combinations even reversed effects of microbiota on TAG. Preservatives had major effects in axenic flies, suggesting either direct effects on the fly or indirect effects via media. However, buffers the fly against this effect, despite the preservatives inhibiting growth, indicating that this bacterium benefits the host in the face of mutual environmental toxicity. Our results suggest that antimicrobial preservatives have major impacts on host TAG, and that microbiota modulates host TAG dependent on the combination of the dietary factors of preservative formula and yeast batch. IMPORTANCE is a premier model for microbiome science, which has greatly enhanced our understanding of the basic biology of host-microbe interactions. However, often overlooked factors such as dietary composition, including yeast batch variability and preservative formula, may confound data interpretation of experiments within the same lab and lead to different findings when comparing between labs. Our study supports this notion; we find that the microbiota does not alter host TAG levels independently. Rather, TAG is modulated by combinatorial effects of microbiota, yeast batch, and preservative formula. Specific preservatives increase TAG even in germ-free flies, showing that a commonplace procedure in fly husbandry alters metabolic physiology. This work serves as a cautionary tale that fly rearing methodology can mask or drive microbiota-dependent metabolic changes and also cause microbiota-independent changes.
Topics: Animals; Drosophila; Gastrointestinal Microbiome; Drosophila melanogaster; Acetobacter; Diet
PubMed: 37800920
DOI: 10.1128/aem.00165-23 -
Biochimica Et Biophysica Acta.... Jan 2024The dysregulation of intestinal microbiota is well-known to be one of the main causes of insulin resistance in both vertebrates and invertebrates. Specially, the...
The dysregulation of intestinal microbiota is well-known to be one of the main causes of insulin resistance in both vertebrates and invertebrates. Specially, the acetobacter and lactobacillus have been identified as potentially capable of alleviating insulin resistance. However, the molecular mechanism underlying this effect requires further elucidation. In this study, we employed Drosophila melanogaster (fruit fly) as a model organism to delineate how intestinal microbiota disrupts the host intestinal signaling pathway, contributing to insulin resistance. Our findings demonstrate that a long-term high-sugar diet lead to a reduction in the general diversity of intestinal microbiota in flies, as well as a marked decrease in the abundances of acetobacter and lactobacillus. Furthermore, we observed that symptoms of insulin resistance were alleviated by feeding flies with acetobacter or lactobacillus, indicating that these microorganisms play an essential role in maintaining blood sugar homeostasis in flies. Conversely, when all intestinal microbiota was removed, flies show severe symptoms of insulin resistance, confirming that the critical role of intestinal microbiota in maintaining host blood sugar homeostasis. Our studies suggested that the intestinal but not fat body JNK pathway mediates the communication of intestinal microbiota and host insulin pathway. In flies, downregulation of JNK activity alleviates symptoms of insulin resistance by decreasing the activity of the JAK/STAT pathway. However, this offsets the therapeutic effects of supplying flies with acetobacter or lactobacillus, suggesting that the therapeutic function of these microorganisms is based on their interaction with JNK-JAK/STAT axis. Taken together, our study reveals that acetobacter and lactobacillus alleviate insulin resistance symptoms in a JNK-JAK/STAT pathway-dependent manner, indicating the therapeutic potential of probiotic supplementation and regulation of the activities of JNK-JAK/STAT pathway for diabetes control.
Topics: Animals; Drosophila melanogaster; Lactobacillus; Acetobacter; Janus Kinases; MAP Kinase Signaling System; Insulin Resistance; Blood Glucose; Signal Transduction; STAT Transcription Factors
PubMed: 37774935
DOI: 10.1016/j.bbadis.2023.166901 -
International Journal of Biological... Dec 2023The family of Acetobacteraceae has demonstrated their ability to produce several heteropolysaccharides with a strong structural resemblance to xanthan gum. In this...
The family of Acetobacteraceae has demonstrated their ability to produce several heteropolysaccharides with a strong structural resemblance to xanthan gum. In this study, we assessed the potential of three isolates of K. baliensis as exopolysaccharide producers, namely K. baliensis SR-745, K. baliensis LMG 27018, and K. baliensis SR-1290. Among these, K. baliensis SR-745 was identified as the most promising candidate, exhibiting a final exopolysaccharide titer of 7.09 (± 0.50) g·L and a productivity of 0.15 (± 0.01) g·L·h. Subsequent monomer analysis confirmed structural variations for the side chain composition of different strains. A molar subunit ratio of 6:1:1:1 (d-glucose: D-mannose: D-galactose: D-glucuronic acid) for EPS derived from K. baliensis SR-745 and of 3:1:3:1 for K. baliensis LMG 27018 was determined, while the exopolysaccharide produced by K. baliensis SR-1290 consisted of a major share of rhamnose. In-depth rheological polymer characterizations revealed high viscosity rates and predominantly elastic gel character, making polysaccharides of K. baliensis highly interesting for applications in the food and cosmetic industry. Further insights into the fundamental structure-function relationships of biopolymers were obtained by comparing exopolysaccharides derived from K. baliensis to a genetically engineered xanthan variant lacking acetyl and pyruvyl substitutions.
Topics: Polysaccharides, Bacterial; Acetobacteraceae; Biopolymers; Viscosity
PubMed: 37769772
DOI: 10.1016/j.ijbiomac.2023.127097