Gut Microbiota, Combined with Metabolomics, Reveals the Mechanism of Curcumol on Liver Fibrosis in Mice

Background:Liver fibrosis is a reversible pathological process, and its prevention and treatment are of great significance to patients with chronic liver disease. This study combined 16S rRNA analysis of gut microbiota and plasma metabolomics to explore the mechanism of curcumol’s effect on liver fibrosis in mice. The results will help to clarify the relationship between the gut microbiota and metabolites in the process of liver fibrosis.Results:Molecular biological testing found that curcumol could significantly improve the pathological changes of liver tissue and inhibit the occurrence of liver inflammation. Intestinal flora testing found that curcumol could significantly change the abundances of Veillonellaceae, Prerotella_oulorum, and Alistipes_finegoldii. Metabolomics analysis found that curcumol’s anti-hepatic fibrosis effect may be related to its regulation of arachidonic acid metabolism. Correlation analysis suggested that curcumol regulated the abundances of Bacteroidota and Bacteroides and participated in the metabolism of Prostaglandin B2.Conclusions:When liver fibrosis occurs, the intestinal flora and metabolic network will be altered. The effect of curcumol on liver fibrosis may be related to its regulation of intestinal flora and the resulting interference with metabolic pathways, thereby regulating liver inflammation.

Molecular identification of isolates from local microorganisms as potential biofertilizer

<p>Local microorganisms (MOL) are liquid fertilizers commonly used by farmers to help increase crop production. Beneficial microbes in MOL need to characterize their interactions and ability to produce growth drive compounds. The purpose of this research is to identify the superior microbial isolates from MOL made by farmers from Cibodas Lembang Bandung, Indonesia that can produce phytohormones as biofertilizers. The results of the microbial selection of MOL derived from three best microbes are 1A-2 NFB, 4A-1 NFB, and 4B-1 NFB with the ability to produce auxin, i.e., 19.41 ppm, 17.18 ppm, and 10.59 ppm, respectively. The compatibility test between the three isolates showed negative results so that it was possible to apply three microbes as a consortium. The results of a molecular identification with a 16S rRNA analysis indicate strain microbe 1A-2 NFB: <em>Bacillus cereus</em> (99.88% homology), 4A-1 NFB: <em>Bacillus cereus</em> (99.76% homology), and 4B-1 NFB: <em>Lysinibacillus</em> sp. (99.88% homology).</p>

Azospirillum Actinidiae sp. nov., a Nitrogen-Fixing Bacterium Isolated From The Roots of Kiwifruit Plants

A novel diazotrophic bacterium, designated CCTCC AB 2021101T, was isolated from fresh roots of kiwifruit. Cells of strain CCTCC AB 2021101T were Gram-negative, aerobic and rod-shaped, with motility provided by peritrichous flagella. The 16S rRNA analysis showed that strain CCTCC AB 2021101T belongs to the genus Azospirillum and is closely related to Azospirillum melinis (98.32%), Azospirillum oryzae (97.73%), Azospirillum lipoferum (96.98%), Azospirillum humicireducens (96.49%) and Azospirillum largimobile (96.01%) and lower sequence similarity (<96.0 %) to all other species of the genus Azospirillum. Strain CCTCC AB 2021101T was able to grow well at 35–40℃ and pH 6.0–7.0, and tolerated up to 3.0 % (w/v) NaCl. The major saturated fatty acids are C14:0, C16:0 and C18:0. C18:1 ω7c and C16:0 3-OH were the major unsaturated and hydroxylated fatty acid. The G+C content was 67.8 mol%. Strain CCTCC AB 2021101T gave positive amplification for dinitrogen reductase (nifH gene). Highest nifH gene sequence similarities were obtained with Azospirillum brasilense AWB14T(95.9%), Azospirillum zeae Gr24T(95.56%), Azospirillum picis DSM 19922T(96.79%), Azospirillum lipoferum B22T(94.88%) and Azospirillum oryzae COC8T(94.88%). The activity of the nitrogenase of the strain was further confirmed by acetylene-reduction assay, which was recorded as 81 nmol ethylene h-1. Based on these data, strain CCTCC AB 2021101T is considered to represent a novel endophytic diazotrophs species in the genus Azospirillum, for which the name Azospirillum actinidiae sp. nov. is proposed. The type strain is CCTCC AB 2021101T.

Thermal resistance and high-performance microwave decontamination assessment of Bacillus endospores isolated from food-grade herbal extracts

Generally, endospore contamination can occur from different sources during product manufacturing in many industries and therefore lower its quality by affecting physicochemical properties and shelf-life. Bacterial endospores can germinate inside the product and produce several enzymes, which can cause several undesirable changes. This study assessed the spores thermal resistance and applied a microwave decontamination technique toward herbal extracts (Tilia tomentosa and Centella asiatica) containing ethanol or glycerol. Based on 16S rRNA analysis, the detected contaminant endospores belonged to different Bacillus species, namely B. subtilis, B. zhangzhouensis, and B. pumilus. The thermal resistance assessment using inoculated endospores in the actual products revealed B. pumilus T2 as the most resistant endospore to the heat treatments tested in both T. tomentosa and C. asiatica extracts. Finally, a high-performance microwave technique was used to decontaminate T. tomentosa extract against the mixture of Bacillus spores. Results from the microwave technique indicate that the increase of temperature from 100°C to 105°C not only decontaminated the product but also could dramatically decrease the effective thermal treatment time (10 times), which can benefit the product quality. The results provided in this study considerably contribute to improving an original decontamination method for products containing glycerol and ethanol with the most negligible effect on product quality.

Yeast β-Glucan Altered Intestinal Microbiome and Metabolome in Older Hens

The prebiotics- and probiotics-mediated positive modulation of the gut microbiota composition is considered a useful approach to improve gut health and food safety in chickens. This study explored the effects of yeast β-glucan (YG) supplementation on intestinal microbiome and metabolites profiles as well as mucosal immunity in older hens. A total of 256 43-week-old hens were randomly assigned to two treatments, with 0 and 200 mg/kg of YG. Results revealed YG-induced downregulation of toll-like receptors (TLRs) and cytokine gene expression in the ileum without any effect on the intestinal barrier. 16S rRNA analysis claimed that YG altered α- and β-diversity and enriched the relative abundance of class Bacilli, orders Lactobacillales and Enterobacteriales, families Lactobacillaceae and Enterobacteriaceae, genera Lactobacillus and Escherichia–Shigella, and species uncultured bacterium-Lactobacillus. Significant downregulation of cutin and suberin, wax biosynthesis, atrazine degradation, vitamin B6 metabolism, phosphotransferase system (PTS), steroid degradation, biosynthesis of unsaturated fatty acids, aminobenzoate degradation and quorum sensing and upregulation of ascorbate and aldarate metabolism, C5-branched dibasic acid metabolism, glyoxylate and dicarboxylate metabolism, pentose and glucuronate interconversions, steroid biosynthesis, carotenoid biosynthesis, porphyrin and chlorophyll metabolism, sesquiterpenoid and triterpenoid biosynthesis, lysine degradation, and ubiquinone and other terpenoid-quinone biosyntheses were observed in YG-treated hens, as substantiated by the findings of untargeted metabolomics analysis. Overall, YG manifests prebiotic properties by altering gut microbiome and metabolite profiles and can downregulate the intestinal mucosal immune response of breeder hens.

First Comparative Analysis of Clostridium septicum Genomes Provides Insights Into the Taxonomy, Species Genetic Diversity, and Virulence Related to Gas Gangrene

Clostridium septicum is a Gram-positive, toxin-producing, and spore-forming bacterium that is recognized, together with C. perfringens, as the most important etiologic agent of progressive gas gangrene. Clostridium septicum infections are almost always fatal in humans and animals. Despite its clinical and agricultural relevance, there is currently limited knowledge of the diversity and genome structure of C. septicum. This study presents the complete genome sequence of C. septicum DSM 7534T type strain as well as the first comparative analysis of five C. septicum genomes. The taxonomy of C. septicum, as revealed by 16S rRNA analysis as well as by genomic wide indices such as protein-based phylogeny, average nucleotide identity, and digital DNA–DNA hybridization indicates a stable clade. The composition and presence of prophages, CRISPR elements and accessory genetic material was variable in the investigated genomes. This is in contrast to the limited genetic variability described for the phylogenetically and phenotypically related species Clostridium chauvoei. The restriction-modification (RM) systems between two C. septicum genomes were heterogeneous for the RM types they encoded. C. septicum has an open pangenome with 2,311 genes representing the core genes and 1,429 accessory genes. The core genome SNP divergence between genome pairs varied up to 4,886 pairwise SNPs. A vast arsenal of potential virulence genes was detected in the genomes studied. Sequence analysis of these genes revealed that sialidase, hemolysin, and collagenase genes are conserved compared to the α-toxin and hyaluronidase genes. In addition, a conserved gene found in all C. septicum genomes was predicted to encode a leucocidin homolog (beta-channel forming cytolysin) similar (71.10% protein identity) to Clostridium chauvoei toxin A (CctA), which is a potent toxin. In conclusion, our results provide first, valuable insights into strain relatedness and genomic plasticity of C. septicum and contribute to our understanding of the virulence mechanisms of this important human and animal pathogen.

Carotenoid Cocktail Produced by An Antarctic Soil Flavobacterium with Biotechnological Potential

Carotenoids are highly important in pigmentation, and its content in farmed crustaceans and fish correlates to their market value. These pigments also have a nutritional role in aquaculture where they are routinely added as a marine animal food supplement to ensure fish development and health. However, there is little information about carotenoids obtained from Antarctic bacteria and its use for pigmentation improvement and flesh quality in aquaculture. This study identified carotenoids produced by Antarctic soil bacteria. The pigmented strain (CN7) was isolated on modified Luria–Bertani (LB) media and incubated at 4 °C. This Gram-negative bacillus was identified by 16S rRNA analysis as Flavobacterium segetis. Pigment extract characterization was performed through high-performance liquid chromatography (HPLC) and identification with liquid chromatography–mass spectrometry (LC–MS). HPLC analyses revealed that this bacterium produces several pigments in the carotenoid absorption range (six peaks). LC–MS confirms the presence of one main peak corresponding to lutein or zeaxanthin (an isomer of lutein) and several other carotenoid pigments and intermediaries in a lower quantity. Therefore, we propose CN7 strain as an alternative model to produce beneficial carotenoid pigments with potential nutritional applications in aquaculture.

Bioplastic Production by Bacillus wiedmannii AS-02 OK576278 Using Different Agricultural Wastes

Polyhydroxybutyrates (PHBs) are macromolecules synthesized by bacteria. Because of their fast degradability under natural environmental conditions, PHBs were selected as alternatives for the production of biodegradable plastics. Sixteen PHB-accumulating strains were selected and compared for their ability to accumulate PHB granules inside their cells. Isolate AS-02 was isolated from cattle manure and identified as Bacillus wiedmannii AS-02 OK576278 by means of 16S rRNA analysis. It was found to be the best producer. The optimum pH, temperature, and incubation period for the best PHB production by the isolate were 7, 35 °C, and 72 h respectively. PHB production was the best with peptone and glucose as nitrogen and carbon sources at a C/N ratio of (2:1). The strain was able to accumulate 423, 390, 249, 158, and 144 mg/L PHB when pretreated orange, mango, banana, onion peels, and rice straw were used as carbon sources, respectively. The extracted polymer was characterized by Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), and GC-MS spectroscopy, which confirmed the structure of the polymer as PHB. The isolate B. wiedmannii AS-02 OK576278 can be considered an excellent candidate for industrial production of PHB from agricultural wastes.

GuanXinNing Tablet Attenuates Alzheimer’s Disease via Improving Gut Microbiota, Host Metabolites, and Neuronal Apoptosis in Rabbits

Based on accumulating evidence, Alzheimer’s disease (AD) is related to hypercholesterolemia, gut microbiota, and host metabolites. GuanXinNing Tablet (GXN) is an oral compound preparation composed of two Chinese herbs, Salvia miltiorrhiza Bge. and Ligusticum chuanxiong Hort., both of which exert neuroprotective effects. Nevertheless, the effect of GXN on AD is unknown. In the present study, we investigated whether GXN alters cholesterol, amyloid-beta (Aβ), gut microbiota, serum metabolites, oxidative stress, neuronal metabolism activities, and apoptosis in an AD model rabbit fed a 2% cholesterol diet. Our results suggested that the GXN treatment significantly reduced cholesterol levels and Aβ deposition and improved memory and behaviors in AD rabbits. The 16S rRNA analysis showed that GXN ameliorated the changes in the gut microbiota, decreased the Firmicutes/Bacteroidetes ratio, and improved the abundances of Akkermansia and dgA-11_gut_group. 1H-NMR metabolomics found that GXN regulated 12 different serum metabolites, such as low-density lipoprotein (LDL), trimethylamine N-oxide (TMAO), and glutamate (Glu). In addition, the 1H-MRS examination showed that GXN remarkably increased N-acetyl aspartate (NAA) and Glu levels while reducing myo-inositol (mI) and choline (Cho) levels in AD rabbits, consequently enhancing neuronal metabolism activities. Furthermore, GXN significantly inhibited oxidative stress and neuronal apoptosis. Taken together, these results indicate that GXN attenuates AD via improving gut microbiota, host metabolites, and neuronal apoptosis.

Halomonas Salinarum sp. nov., a Moderately Halophilic Bacterium, Isolated from Saline Soil in Yingkou, China

Strains of Halomonas, thought to play vital roles in the environment for their versatility, are ubiquitous in hypersaline environments. A Gram-staining-negative, moderately halotolerant, facultatively aerobic, motile bacterium, designated G5-11T, was isolated from saline soil in Yingkou of Liaoning, China. The cells of strain G5-11T grew at 4-35 ℃ (optimum 30 ℃), at pH 6.0-9.0 (optimum 8.0) and in the presense of 3-15 % (w/v) NaCl (optimum 5 %). The strain could be clearly distinguished from the related species of the genus Halomonas by its phylogenetic position and biochemical characteristics. It presented Q-9 as the major respiratory quinone and the dominant cellular fatty acids were summed feature 8 (C18:1 ω7c/ C18:1 ω6c), C16:0 and summed feature 3 (C16:1 ω7c/ C16:1 ω6c). The polar lipids consisted of phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol as the major components. The G+C content of strain G5-11T genome was 61.0 mol%. 16S rRNA analysis showed that strain G5-11T had the highest similarity to Halomonas niordiana LMG 31227T and Halomonas taeanensis DSM 16463T, both reaching 98.3 %, followed by Halomonas pacifica NBRC 102220T with a value of 95.8 %. Based on phenotypic, chemotaxonomic and phylogenetic inferences, strain G5-11T represents a novel species of the genus Halomonas, for which the name Halomonas salinarum sp. nov. is proposed. The type strain of Halomonas salinarum is G5-11T (=CGMCC 1.12051T=LMG 31677T).