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1.
Nat Commun ; 12(1): 3673, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34135318

RESUMO

Mitochondrial ribosomes (mitoribosomes) synthesize a critical set of proteins essential for oxidative phosphorylation. Therefore, mitoribosomal function is vital to the cellular energy supply. Mitoribosome biogenesis follows distinct molecular pathways that remain poorly understood. Here, we determine the cryo-EM structures of mitoribosomes isolated from human cell lines with either depleted or overexpressed mitoribosome assembly factor GTPBP5, allowing us to capture consecutive steps during mitoribosomal large subunit (mt-LSU) biogenesis. Our structures provide essential insights into the last steps of 16S rRNA folding, methylation and peptidyl transferase centre (PTC) completion, which require the coordinated action of nine assembly factors. We show that mammalian-specific MTERF4 contributes to the folding of 16S rRNA, allowing 16 S rRNA methylation by MRM2, while GTPBP5 and NSUN4 promote fine-tuning rRNA rearrangements leading to PTC formation. Moreover, our data reveal an unexpected involvement of the elongation factor mtEF-Tu in mt-LSU assembly, where mtEF-Tu interacts with GTPBP5, similar to its interaction with tRNA during translational elongation.


Assuntos
Ribossomos Mitocondriais/química , Subunidades Ribossômicas Maiores/química , Linhagem Celular , Microscopia Crioeletrônica , Humanos , Metiltransferases/química , Metiltransferases/metabolismo , Ribossomos Mitocondriais/metabolismo , Modelos Moleculares , Proteínas Monoméricas de Ligação ao GTP/química , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Complexos Multiproteicos , Fator Tu de Elongação de Peptídeos/química , Fator Tu de Elongação de Peptídeos/metabolismo , Peptidil Transferases/química , Peptidil Transferases/metabolismo , Ligação Proteica , Dobramento de RNA , RNA Ribossômico 16S/química , RNA Ribossômico 16S/metabolismo , Subunidades Ribossômicas Maiores/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo
2.
BMC Infect Dis ; 21(1): 583, 2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34134659

RESUMO

BACKGROUND: Previous studies showed that type 2 short bowel syndrome (SBS) rats were accompanied by severe intestinal bacterial dysbiosis. Limited data are available for intestinal fungal dysbiosis. Moreover, no effective therapeutic drugs are available for these microbiota dysbiosis. The aims of our study were to investigate the therapeutic potential of glucagon-like peptide 2 (GLP-2) for these microbiota dysbiosis in type 2 SBS rats. METHODS: 8-week-old male SD rats which underwent 80% small bowel resection, ileocecum resection, partial colon resection and jejunocolostomy, were treated with saline (SBS group, n = 5) or GLP-2 (GLP2.SBS group, n = 5). The Sham group rats which underwent transection and re-anastomosis were given a saline placebo (Sham group, n = 5). 16S rRNA and ITS sequencing were applied to evaluate the colonic bacterial and fungal composition at 22 days after surgery, respectively. RESULTS: The relative abundance of Actinobacteria, Firmicutes and proinflammatory Proteobacteria increased significantly in SBS group rats, while the relative abundance of Bacteroidetes, Verrucomicrobia and Tenericutes decreased remarkably. GLP-2 treatment significantly decreased Proteus and increased Clostridium relative to the saline treated SBS rats. The diversity of intestinal fungi was significantly increased in SBS rats, accompanied with some fungi abnormally increased and some resident fungi (e.g., Penicillium) significantly decreased. GLP-2 treatment significantly decreased Debaryomyces and Meyerozyma, and increased Penicillium. Moreover, GLP-2 partially restored the bacteria-fungi interkingdom interaction network of SBS rats. CONCLUSION: Our study confirms the bacterial and fungal dysbiosis in type 2 SBS rats, and GLP-2 partially ameliorated these microbiota dysbiosis.


Assuntos
Microbioma Gastrointestinal/efeitos dos fármacos , Peptídeo 2 Semelhante ao Glucagon/farmacologia , Intestinos/microbiologia , Síndrome do Intestino Curto/patologia , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Animais , Colo/cirurgia , Colostomia , Análise Discriminante , Modelos Animais de Doenças , Disbiose , Fungos/genética , Fungos/isolamento & purificação , Peptídeo 2 Semelhante ao Glucagon/uso terapêutico , Análise dos Mínimos Quadrados , Masculino , Análise de Componente Principal , RNA Ribossômico 16S/análise , RNA Ribossômico 16S/metabolismo , Ratos , Ratos Sprague-Dawley , Síndrome do Intestino Curto/tratamento farmacológico , Síndrome do Intestino Curto/microbiologia
3.
Animal ; 15(7): 100259, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34058595

RESUMO

A considerable amount of trimethylamine (TMA) is likely generated in the rumen; however, its metabolism is still unclear. This study aimed to investigate the role of Methanomassiliicoccales (Mmc) in TMA metabolism in the rumen of dairy cows. Three experiments, two rumen in vitro fermentation trials and one dairy cow in vivo trial, were conducted. Four groups were set in Experiment 1: control, nitroglycerin (NG, a methanogen inhibitor), TMA (7.2 mmol/L), and TMA + NG. The methanogenic activity was completely inhibited in the NG group, and no methane production was observed in the NG and TMA + NG groups. The TMA content hardly reduced in the TMA + NG group (6.9 mmol/L) following a 2 d-incubation; in contrast, it demonstrated a significant reduction by 47.2% in the TMA group. Methanogen 16S rRNA gene sequencing and real-time PCR showed that the relative abundance of Mmc increased in the TMA group (P = 0.005). The increase was mainly attributed to two species-level taxa, Group 9 sp. ISO4-G1 and Group 10 sp. Four groups were set in Experiment 2: control, NG, choline (choline chloride, 7.2 mmol/L), and choline + NG. Choline was completely degraded in 24 h, and the TMA content reached the peak point (7.3 mmol/L) in the fermentation culture. The TMA content remained relatively stable in the choline + NG group following the peak point. However, it started to decrease after 24 h in the choline group, corresponding to the rapid increase in methane production and the abundance of Mmc. Eight mid-lactating, rumen-fistulated Holstein cows were randomly assigned to the control (n = 4) or choline (n = 4) group in Experiment 3: In the choline group, cows were gradually supplemented with 100-250 g/(cow·d) of choline chloride over 4 weeks. Compared to the control group, TMA accumulated in the rumen fluid, and the abundance of Mmc 16S rRNA gene and choline-degrading bacterial cutC gene increased in the rumen content in the choline group (P < 0.050). The trimethylamine N-oxide content in the plasma and milk of the dairy cows was approximately 10 times higher in the choline group than that in the control at the end of the experiment. These findings revealed that Mmc played an important role in the elimination of TMA in the rumen. The accumulation of TMA in the rumen would lead to a large amount of TMA absorbed into the blood stream of the dairy cows.


Assuntos
Lactação , Rúmen , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Suplementos Nutricionais , Feminino , Fermentação , Metano/metabolismo , Metilaminas , Leite , RNA Ribossômico 16S/metabolismo , Rúmen/metabolismo
4.
J Dairy Sci ; 104(8): 8721-8735, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34024597

RESUMO

The purpose of this study was to investigate the effect of 3-nitrooxypropanol (3-NOP), a potent methane inhibitor, on total and metabolically active methanogens in the rumen of dairy cows over the course of the day and over a 12-wk period. Rumen contents of 8 ruminally cannulated early-lactation dairy cows were sampled at 2, 6, and 10 h after feeding during wk 4, 8, and 12 of a randomized complete block design experiment in which 3-NOP was fed at 60 mg/kg of feed dry matter. Cows (4 fed the control and 4 fed the 3-NOP diet) were blocked based on their previous lactation milk yield or predicted milk yield. Rumen samples were extracted for microbial DNA (total) and microbial RNA (metabolically active), PCR amplified for the 16S rRNA gene of archaea, sequenced on an Illumina platform, and analyzed for archaea diversity. In addition, the 16S copy number and 3 ruminal methanogenic species were quantified using the real-time quantitative PCR assay. We detected a difference between DNA and RNA (cDNA)-based archaea communities, revealing that ruminal methanogens differ in their metabolic activities. Within DNA and cDNA components, methanogenic communities differed by sampling hour, week, and treatment. Overall, Methanobrevibacter was the dominant genus (94.3%) followed by Methanosphaera, with the latter genus having greater abundance in the cDNA component (14.5%) compared with total populations (5.5%). Methanosphaera was higher at 2 h after feeding, whereas Methanobrevibacter increased at 6 and 10 h in both groups, showing diurnal patterns among individual methanogenic lineages. Methanobrevibacter was reduced at wk 4, whereas Methanosphaera was reduced at wk 8 and 12 in cows supplemented with 3-NOP compared with control cows, suggesting differential responses among methanogens to 3-NOP. A reduction in Methanobrevibacter ruminantium in all 3-NOP samples from wk 8 was confirmed using real-time quantitative PCR. The relative abundance of individual methanogens was driven by a combination of dietary composition, dry matter intake, and hydrogen concentrations in the rumen. This study provides novel information on the effects of 3-NOP on individual methanogenic lineages, but further studies are needed to understand temporal dynamics and to validate the effects of 3-NOP on individual lineages of ruminal methanogens.


Assuntos
Propanóis , Rúmen , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Feminino , Fermentação , Lactação , Metano/metabolismo , Leite , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Rúmen/metabolismo
5.
Environ Sci Technol ; 55(12): 7970-7980, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34041904

RESUMO

Reliance on bioremediation to remove benzene from anoxic environments has proven risky for decades but for unknown reasons. Research has revealed a strong link between anaerobic benzene biodegradation and the enrichment of highly specific microbes, including Thermincola in the family Peptococcaceae and the deltaproteobacterial Candidate Sva0485 clade. Using aquifer materials from Canadian Forces Base Borden, we compared five bioremediation approaches in batch microcosms. Under conditions simulating natural attenuation or sulfate biostimulation, benzene was not degraded after 1-2 years of incubation and no enrichment of known benzene-degrading microbes occurred. In contrast, nitrate-amended microcosms reported benzene biodegradation coincident with significant growth of Thermincola spp., along with a functional gene presumed to catalyze anaerobic benzene carboxylation (abcA). Inoculation with 2.5% of a methanogenic benzene-degrading consortium containing Sva0485 (Deltaproteobacteria ORM2) resulted in benzene biodegradation in the presence of sulfate or under methanogenic conditions. The presence of other hydrocarbon co-contaminants decreased the rates of benzene degradation by a factor of 2 to 4. Tracking the abundance of the abcA gene and 16S rRNA genes specific for benzene-degrading Thermincola and Sva0485 is recommended to monitor benzene bioremediation in anoxic groundwater systems to further uncover growth-rate-limiting conditions for these two intriguing phylotypes.


Assuntos
Benzeno , Anaerobiose , Biodegradação Ambiental , Canadá , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo
6.
Food Chem ; 360: 129981, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34020366

RESUMO

Egg white peptides (EWPs) can be effectively used to alleviate and treat inflammatory diseases due to their anti-oxidation, anti-inflammation, and microbiota regulation capabilities. A dextran sodium sulfate (DSS)-induced colitis model was used to clarify the regulatory effects of EWPs on colitis. Forty-three peptide sequences were identified from EWPs using LC-MS/MS. The results demonstrated that EWPs decreased the levels of pro-inflammatory cytokines and the extent of crypt damage in a dose-dependent manner. 16S rRNA gene sequencing results indicated that 200 mg/kg EWPs significantly increased the relative abundance of beneficial bacteria Lactobacillus and Candidatus_Saccharimonas, and reduced the relative abundance of pathogenic bacteria Ruminiclostridium and Akkermansia. In addition, the degree of correlation between pro-inflammatory cytokines and microbiota was as follows: interleukin (IL)-1ß > IL-8 > IL-6 > tumor necrosis factor-α To summarize, EWPs contributed to the alleviation of colitis symptoms and the intestinal injury through anti-inflammatory effects, repair of intestinal mucosa, and modulation of gut microbiota.


Assuntos
Colo/metabolismo , Citocinas/metabolismo , Clara de Ovo/química , Microbioma Gastrointestinal/efeitos dos fármacos , Peptídeos/farmacologia , Sequência de Aminoácidos , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/microbiologia , Colite/patologia , Colo/efeitos dos fármacos , Colo/microbiologia , Colo/patologia , Sulfato de Dextrana/toxicidade , Proteínas do Ovo/química , Proteínas do Ovo/metabolismo , Lactobacillus/genética , Lactobacillus/isolamento & purificação , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Peptídeos/análise , Peptídeos/uso terapêutico , RNA Ribossômico 16S/análise , RNA Ribossômico 16S/metabolismo , Espectrometria de Massas em Tandem
7.
Ecotoxicol Environ Saf ; 215: 112108, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33799132

RESUMO

Fluoride which is widespread in our environment and food due to its geological origin and industrial pollution has been identified as a developmental neurotoxicant. Gut-brain axis provides new insight into brain-derived injury. We previously found the psychoactive effects of a probiotic strain, Lactobacillus johnsonii BS15 against fluoride-induced memory dysfunction in mice by modulating the gut-brain axis. In this study, we aimed to detect the link between the reconstruction of gut microbiota and gut-brain axis through which probiotic alleviate fluoride-induced memory impairment. We also added an hour of water avoidance stress (WAS) before behavioral tests and sampling, aiming to demonstrate the preventive effects of the probiotic on fluoride-induced memory impairment after psychological stress. Mice were given fluoridated drinking water (sodium fluoride 100 ppm, corresponding to 37.8 ± 2.4 ppm F¯) for 70 days and administered with PBS or a probiotic strain, Lactobacillus johnsonii BS15 for 28 days prior to and throughout a 70 day exposure to sodium fluoride. Results showed that fluoride increases the hyperactivity of hypothalamic-pituitary-adrenal (HPA) axis and reduces the exploration ratio in novel object recognition (NOR) test and the spontaneous exploration during the T-maze test in mice following WAS, which were significantly improved by the probiotic. 16S rRNA sequencing showed a significant separation in ileal microbiota between the fluoride-treated mice and control mice. Lactobacillus was the main targeting bacteria and significantly reduced in fluoride-treated mice. BS15 reconstructed the fluoride-post microbiota and increased the relative abundance of Lactobacillus. D-lactate content and diamine oxidase (DAO) activity, two biomarkers of gut permeability were reduced in the serum of probiotic-inoculated mice. ZO-1, an intestinal tight junction protein was reduced by fluoride in mRNA, and its protein levels were increased by the probiotic treatment. Moreover, the hippocampus which is essential to learning and memory, down-regulated mRNA level of both the myelin-associated glycoprotein (MAG), and protein levels of brain-derived neurotrophic factor (BDNF), including the improvement of cAMP response element-binding protein (CREB) by BS15 in fluoride-exposed mice after WAS. Via spearman correlation analysis, Lactobacillus displayed significantly positive associations with the behavioral tests, levels of nerve development related factors, and intestinal tight junction proteins ZO-1, and negative association with TNF-α of the hippocampus, highlighting regulatory effects of gut bacteria on memory potential and gut barrier. These results suggested the psychoactive effects of BS15 on fluoride-induced memory dysfunction after psychological stress. In addition, there may be some correlations between fluoride-induced memory dysfunction and reconstruction of gut microbiota. AVAILABILITY OF DATA AND MATERIALS: 16S rRNA sequencing reads have uploaded to NCBI. The accession code of 16S rRNA sequencing reads in the National Center for Biotechnology Information (NCBI) BioProject database: PRJNA660154.


Assuntos
Fluoretos/metabolismo , Microbioma Gastrointestinal/fisiologia , Probióticos/farmacologia , Animais , Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Hipocampo/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Lactobacillus/metabolismo , Masculino , Memória , Transtornos da Memória/induzido quimicamente , Camundongos , Microbiota , Sistema Hipófise-Suprarrenal/metabolismo , RNA Ribossômico 16S/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Proteína da Zônula de Oclusão-1/metabolismo
8.
Molecules ; 26(9)2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33922589

RESUMO

In vitro experiments have indicated prebiotic activity of isomaltulose, which stimulates the growth of probiotics and the production of short chain fatty acids (SCFAs). However, the absence of in vivo trials undermines these results. This study aims to investigate the effect of isomaltulose on composition and functionality of gut microbiota in rats. Twelve Sprague-Dawley rats were divided into two groups: the IsoMTL group was given free access to water containing 10% isomaltulose (w/w), and the control group was treated with normal water for five weeks. Moreover, 16S rRNA sequencing showed that ingestion of isomaltulose increased the abundances of beneficial microbiota, such as Faecalibacterium and Phascolarctobacterium, and decreased levels of pathogens, including Shuttleworthia. Bacterial functional prediction showed that isomaltulose affected gut microbial functionalities, including secondary bile acid biosynthesis. Targeted metabolomics demonstrated that isomaltulose supplementation enhanced cholic acid concentration, and reduced levels of lithocholic acid, deoxycholic acid, dehydrocholic acid, and hyodeoxycholic acid. Moreover, the concentrations of propionate and butyrate were elevated in the rats administered with isomaltulose. This work suggests that isomaltulose modulates gut microbiota and the production of SCFAs and secondary bile acids in rats, which provides a scientific basis on the use of isomaltulose as a prebiotic.


Assuntos
Ácidos e Sais Biliares/metabolismo , Ácidos Graxos Voláteis/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacos , Isomaltose/análogos & derivados , Probióticos/farmacologia , Animais , Teste de Tolerância a Glucose , Isomaltose/farmacologia , Masculino , RNA Ribossômico 16S/metabolismo , Ratos , Ratos Sprague-Dawley
9.
Nutrients ; 13(3)2021 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33801119

RESUMO

The incidence of obesity, which is closely associated with the gut microbiota and chronic inflammation, has rapidly increased in the past 40 years. Therefore, the probiotic-based modification of the intestinal microbiota composition has been developed as a strategy for the treatment of obesity. In this study, we selected four Bifidobacterium adolescentis strains isolated from the feces of newborn and elderly humans to investigate whether supplementation with B. adolescentis of various origins could alleviate obesity in mice. Male C57BL/6J mice fed a high-fat diet (HFD, 60% energy as fat) received one of the following 14-week interventions: (i) B. adolescentis N4_N3, (ii) B. adolescentis Z25, (iii) B. adolescentis 17_3, (iv) B. adolescentis 2016_7_2, and (v) phosphate-buffered saline. The metabolic parameters, thermogenesis, and immunity of all treated mice were measured. Cecal and colonic microbial profiles were determined by 16S rRNA gene sequencing. Intestinal concentrations of short-chain fatty acids (SCFAs) were measured by gas chromatography-mass spectrometry (GC-MS). The B. adolescentis strains isolated from the feces of elderly humans (B. adolescentis Z25, 17_3, and 2016_7_2) decreased the body weight or weight gain of mice, whilst the strain isolated from the newborn (B. adolescentis N4_N3) increased the body weight of mice. The B. adolescentis strains isolated from the elderly also increased serum leptin concentrations and induced the expression of thermogenesis- and lipid metabolism-related genes in brown adipose tissue. All the B. adolescentis strains alleviated inflammations in the spleen and brain and modified the cecal and colonic microbiota. Particularly, all strains reversed the HFD-induced depletion of Bifidobacterium and reduced the development of beta-lactam resistance. In addition, the B. adolescentis strains isolated from the elderly increased the relative abundances of potentially beneficial genera, such as Bacteroides, Parabacteroides, and Faecalibaculum. We speculate that such increased abundance of commensal bacteria may have mediated the alleviation of obesity, as B. adolescentis supplementation decreased the intestinal production of SCFAs, thereby reducing energy delivery to the host mice. Our results revealed that certain strains of B. adolescentis can alleviate obesity and modify the gut microbiota of mice. The tested strains of B. adolescentis showed different effects on lipid metabolism and immunity regulation, with these effects related to whether they had been isolated from the feces of newborn or elderly humans. This indicates that B. adolescentis from different sources may have disparate effects on host health possibly due to the transmission of origin-specific functions to the host.


Assuntos
Bifidobacterium adolescentis/isolamento & purificação , Bifidobacterium adolescentis/metabolismo , Dieta Hiperlipídica/efeitos adversos , Microbioma Gastrointestinal/fisiologia , Tecido Adiposo Marrom/metabolismo , Animais , Bifidobacterium adolescentis/genética , Colo/microbiologia , Citocinas/metabolismo , Ácidos Graxos Voláteis/metabolismo , Fezes/microbiologia , Microbioma Gastrointestinal/genética , Imunidade , Inflamação/metabolismo , Intestinos , Metabolismo dos Lipídeos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Probióticos , RNA Ribossômico 16S/metabolismo , Ganho de Peso
10.
J Dairy Sci ; 104(7): 7781-7793, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33865598

RESUMO

We reported recently that adding bakery by-products (BP) to the diets of dairy cows up to 30% improved performance and rumen pH, but caused major shifts in the nutrient profile and availability, likely modifying nutrient degradation patterns throughout the gastrointestinal tract. The aim of this study was to investigate the effects of the gradual replacement of cereals by BP on the apparent total-tract digestibility (ATTD), the fermentation patterns, and the microbial community in feces of dairy cows. Twenty-four mid-lactating Simmental cows (149 ± 22.3 days in milk, 756 ± 89.6 kg of initial body weight) were fed a total mixed ration ad libitum (fresh feed was offered twice per day) containing a 50:50 ratio of forage to concentrate (dry matter basis) throughout the experiment. The trial lasted 5 wk, whereby the first week was used for baseline measurements, in which all cows received the same diet, without BP. Cows were then randomly allocated into 3 groups differing in the BP content of diets (0% BP, 15% BP, and 30% BP on a DM basis) and fed for 4 wk. Fecal samples were taken for analysis of pH, volatile fatty acids (VFA), and 16S rRNA gene sequencing. The inclusion of BP resulted in an increase of ether extract and sugars, and a reduction of starch and neutral detergent fiber in the diet. Feeding BP linearly increased the ATTD of almost all nutrients resulting in up to 2 kg more digestible organic matter intake (DOMI). Increasing BP level up to 30% increased fecal total VFA concentration and decreased the pH. The proportion of butyrate in feces increased linearly, but the proportion of all other VFA was not affected by BP-feeding. The richness and diversity indices of the fecal microbiota linearly declined by the inclusion of BP. The cellulolytic phyla Fibrobacteres decreased, whereas amylolytic phyla, such as Proteobacteria, increased. Overall, results showed that feeding BP linearly increased ATTD and DOMI, but impaired fecal microbial diversity and pH. In the interest of the optimization of BP inclusion in the dairy cows' feeding, a dietary level between 15 to 30% of BP might be a better compromise than 30% in terms of an enhanced DOMI and performance with still lowered risk of hindgut dysbiosis, but this will require further investigations.


Assuntos
Ração Animal , Lactação , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Fibras na Dieta/metabolismo , Digestão , Fezes , Feminino , Fermentação , Concentração de Íons de Hidrogênio , Leite , Nutrientes , RNA Ribossômico 16S/metabolismo , Rúmen/metabolismo
11.
Int J Mol Sci ; 22(7)2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33805848

RESUMO

Lantibiotics are a type of bacteriocin produced by Gram-positive bacteria and have a wide spectrum of Gram-positive antimicrobial activity. In this study, we determined that Mutacin I/III and Smb (a dipeptide lantibiotic), which are mainly produced by the widespread cariogenic bacterium Streptococcus mutans, have strong antimicrobial activities against many of the Gram-positive bacteria which constitute the intestinal microbiota. These lantibiotics also demonstrate resistance to acid and temperature. Based on these features, we predicted that lantibiotics may be able to persist into the intestinal tract maintaining a strong antimicrobial activity, affecting the intestinal microbiota. Saliva and fecal samples from 69 subjects were collected to test this hypothesis and the presence of lantibiotics and the composition of the intestinal microbiota were examined. We demonstrate that subjects possessing lantibiotic-producing bacteria in their oral cavity exhibited a tendency of decreased species richness and have significantly reduced abundance of the phylum Firmicutes in their intestinal microbiota. Similar results were obtained in the fecal microbiota of mice fed with S. mutans culture supernatant containing the lantibiotic bacteriocin Mutacin I. These results showed that lantibiotic bacteriocins produced in the oral cavity perturb the intestinal microbiota and suggest that oral bacteria may be one of the causative factors of intestinal microbiota dysbiosis.


Assuntos
Bacteriocinas/farmacologia , Disbiose/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Boca/microbiologia , Animais , Anti-Infecciosos/farmacologia , Fezes/microbiologia , Feminino , Firmicutes , Camundongos , Camundongos Endogâmicos ICR , RNA Ribossômico 16S/metabolismo , Streptococcus mutans , Temperatura
12.
Carbohydr Polym ; 260: 117807, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33712153

RESUMO

To date, the production of bacterial nanocellulose (BNC) by standard methods has been well known, while the use of low-cost feedstock as an alternative medium still needs to be explored for BNC commercialization. This study explores the prospect for the use of the different aqueous extract of fruit peel wastes (aE-FPW) as a nutrient and carbon source for the production of BNC. Herein, this objective was accomplished by the use of a novel, high- yielding strain, isolated from rotten apple and further identified as Komagataeibacter xylinus IITR DKH20 using 16 s rRNA sequencing analysis. The physicochemical properties of BNC matrix collected from the various aE-FPW mediums were similar or advanced to those collected with the HS medium. Statistical optimization of BNC based on Central Composite Design was performed to study the effect of significant parameters and the results demonstrated that the BNC yield (11.44 g L-1) was increased by 4.5 fold after optimization.


Assuntos
Acetobacteraceae/metabolismo , Celulose/metabolismo , Nanoestruturas/química , Acetobacteraceae/classificação , Acetobacteraceae/genética , Acetobacteraceae/isolamento & purificação , Celulose/química , Celulose/isolamento & purificação , Frutas/microbiologia , Malus/microbiologia , Microscopia de Força Atômica , Filogenia , RNA Ribossômico 16S/química , RNA Ribossômico 16S/isolamento & purificação , RNA Ribossômico 16S/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Food Chem ; 355: 129586, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33773458

RESUMO

In order to invent a porcine gelatine detection device using microbial resources, bacterial enzymes with a preference towards porcine gelatine and their candidate genes were evaluated. Five (n = 5) bacterial strains isolated from hot spring water and wet clay, Malaysia were screened for their gelatinase activity. The gelatinase enzyme was extracted and purified using ammonium sulphate precipitation prior to performing gelatinase assay on porcine, bovine and fish gelatine medium substrates. The G2 strain or Enterobacter aerogenes (Strain EA1) was selected for whole genome sequenced after showing a consistent trend of preference towards porcine gelatine. The gelatinase candidate gene gelEA1_9 was cloned and expressed. Based on one-way analysis of variance (ANOVA) with POST-HOC Duncan test (α = 0.05), the final product of gelEA1_9 was identified as a novel gelatinase. This gelatinase presented no significant difference in activity towards porcine gelatine. Hence, the present study demonstrated an enzyme-substrate interaction for porcine gelatine identification.


Assuntos
Proteínas de Bactérias/metabolismo , Gelatina/metabolismo , Gelatinases/metabolismo , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Bovinos , Enterobacter aerogenes/enzimologia , Enterobacter aerogenes/genética , Peixes/metabolismo , Gelatinases/química , Gelatinases/genética , Expressão Gênica , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Alinhamento de Sequência , Especificidade por Substrato , Suínos
14.
Appl Microbiol Biotechnol ; 105(8): 3289-3300, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33768310

RESUMO

This study aimed to determine the influence of sorghum ensiled with unsalable pumpkin at 20 or 40% dry matter (DM) basis on rumen fermentation characteristics and rumen microbial communities using the rumen simulation technique (RUSITEC). The experiment used a completely randomised design including silages comprising (1) 100% sorghum; (2) 80% sorghum + 20% DM pumpkin; or (3) 60% sorghum + 40% DM pumpkin. Each RUSITEC run (n = 2) was 15 d long, including 6 d of adaptation and 9 d of sampling. Dry matter digestibility (DMD) was measured on d 8 and 10-13. Gas production was measured daily, whereas methane and volatile fatty acids (VFA) production were measured from d 7-15. Solid-associated microbes (SAM) were collected on d 5, 10 and 15, whereas liquid-associated microbes (LAM) were collected after 15-d incubation. The V4 region of the 16S rRNA gene and the ITS1 region were sequenced to identify archaeal, bacterial and fungal communities. Ensiling 40% DM pumpkin with sorghum increased DMD and decreased the ratio of acetate to propionate (P ≤ 0.01). Both bacterial SAM and LAM communities were dominated by Megasphaera, and had the highest relative abundance (P = 0.03) with 40% DM pumpkin after 5 d incubation in the SAM community, while species of the Aspergillus genus dominated fungal SAM and LAM communities with 20 or 40% DM unsalable pumpkin. Therefore, ensiling up to 40% DM unsalable pumpkin with sorghum produces a high-quality ruminant feed with minimal influence on the rumen microbial population. KEY POINTS: • Including 40% DM unsalable pumpkin decreased acetate:propionate • Ensiling unsalable pumpkin with sorghum increases digestibility in a RUSITEC • Rumen microbial communities were slightly influenced by unsalable pumpkin inclusion.


Assuntos
Cucurbita , Sorghum , Ração Animal/análise , Animais , Dieta , Digestão , Fermentação , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Rúmen/metabolismo , Silagem
15.
J Dairy Sci ; 104(4): 4326-4340, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33589262

RESUMO

Dietary supplementation of alfalfa hay or calf starter during the preweaning period was beneficial to the gastrointestinal development in dairy calves and lambs. In the present study, we designed 2 experiments using weaning with calf starter and alfalfa hay to investigate the diet-ruminal microbiome-host crosstalk in yak calves by analyzing the ruminal microbiota and rumen epithelial transcriptome. During the preweaning period, supplementation with either alfalfa hay or the starter significantly promoted animal growth and organ development in yak calves, including increases in body weight, body height, body length, chest girth, and development of liver, spleen, and thymus. These improvements could be attributed to increased dry matter intake, rumen fermentation, and development. Butyrate concentration increased in yak calves fed alfalfa hay or the starter, which could further promote ruminal epithelium development. Using 16S rRNA gene amplicon sequencing, we determined that butyrate-producing genera were increased by the supplementation with alfalfa hay or the starter. Transcriptomic analysis of the rumen epithelia revealed that the PI3K-Akt signaling pathway, which is critical in mediating many aspects of cellular function such as cell growth, was upregulated in response to alfalfa hay or the starter supplementation. The starter supplementation also increased the jejunal α-amylase activity, whereas alfalfa hay supplementation reduced the ileal α-amylase activity. Furthermore, the co-supplementation of both the starter and alfalfa hay reduced intestinal α-amylase activity. The starter increased ruminal propionate concentration, whereas alfalfa hay exhibited the opposite trend. The observed opposite effects of the starter and alfalfa hay on rumen propionate concentration corresponded with up- and downregulation, respectively, of the ruminal cholecystokinin involved in pancreatic secretion pathway, and thereby increased and decreased pancreatic α-amylase activity. In conclusion, both alfalfa hay and the starter could promote the growth and ruminal epithelial development of yak calves. The starter and alfalfa hay also differentially affected the intestinal α-amylase activities due to their different chemical components and different effects on ruminal fermentation, especially the ruminal propionate production.


Assuntos
Microbiota , Rúmen , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Ácidos Graxos Voláteis/metabolismo , Fermentação , Medicago sativa , alfa-Amilases Pancreáticas/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , RNA Ribossômico 16S/metabolismo , Rúmen/metabolismo , Ovinos , Desmame
16.
Cell Mol Life Sci ; 78(6): 2585-2606, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33582841

RESUMO

Hospital-associated infections are a major concern for global public health. Infections with antibiotic-resistant pathogens can cause empiric treatment failure, and for infections with multidrug-resistant bacteria which can overcome antibiotics of "last resort" there exists no alternative treatments. Despite extensive sanitization protocols, the hospital environment is a potent reservoir and vector of antibiotic-resistant organisms. Pathogens can persist on hospital surfaces and plumbing for months to years, acquire new antibiotic resistance genes by horizontal gene transfer, and initiate outbreaks of hospital-associated infections by spreading to patients via healthcare workers and visitors. Advancements in next-generation sequencing of bacterial genomes and metagenomes have expanded our ability to (1) identify species and track distinct strains, (2) comprehensively profile antibiotic resistance genes, and (3) resolve the mobile elements that facilitate intra- and intercellular gene transfer. This information can, in turn, be used to characterize the population dynamics of hospital-associated microbiota, track outbreaks to their environmental reservoirs, and inform future interventions. This review provides a detailed overview of the approaches and bioinformatic tools available to study isolates and metagenomes of hospital-associated bacteria, and their multi-layered networks of transmission.


Assuntos
Bactérias/genética , Infecção Hospitalar/patologia , Farmacorresistência Bacteriana Múltipla/genética , Antibacterianos/uso terapêutico , Bactérias/classificação , Bactérias/isolamento & purificação , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/microbiologia , Transferência Genética Horizontal , Humanos , Metagenômica , Plasmídeos/genética , Plasmídeos/metabolismo , RNA Ribossômico 16S/química , RNA Ribossômico 16S/classificação , RNA Ribossômico 16S/metabolismo , Sequenciamento Completo do Genoma
17.
Animal ; 15(3): 100019, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33610512

RESUMO

The caecum is the primary site where microbial fermentation and acidosis occurred. The supplementation of starter feed and alfalfa hay has the potential to influence caecal microbiota and then affect caecal fermentation. This study aims to investigate the effect of starter feed and alfalfa hay supplementation on caecal microbiota, immune homeostasis, and growth of preweaning yaks. Twenty 30-day-old male yak calves were randomly assigned to four groups, which separately fed with milk replacer (CON group), milk replacer with alfalfa hay (A group), milk replacer with starter feed (S group), and milk replacer with starter feed plus alfalfa hay (SA group) throughout the trial. Growth performance and plasma physiological and biochemical indicators were measured every 30 days. Calves were sacrificed at 120 days of age. The caecal contents were collected for measuring pH and contents of volatile fatty acids (VFAs) and lipopolysaccharide (LPS) and for characterizing caecal microbiota. The results indicated that individual or simultaneous supplementation with alfalfa hay and starter feed all significantly increased the BW, body height, body length, and chest girth of yak calves. However, supplementation with starter feed significantly increased plasma cortisol, nitric oxide, tumor necrosis factor-α, and interferon-γ concentrations and the ratio of aspartate aminotransferase to alanine aminotransferase of yak calves when compared with the control and alfalfa hay feeding groups, while the co-supplementation of starter feed and alfalfa hay could significantly decrease these inflammation-related indices when compared with the starter feeding group. Sequencing of the 16S rRNA gene showed that starter feed and alfalfa hay separately stimulated the proliferation of starch-decomposing and cellulose- or hemicellulose-decomposing bacteria. This also significantly increased the levels of acetate, propionate, butyrate, valerate, isobutyrate, and isovalerate in the caecal contents. Furthermore, compared with the S and CON groups, the significantly increased genera of Desulfobulbus, Olsenella, Pseudoflavonifractor, and Stomatobaculum in the SA and A groups were beneficial to the immune homeostasis, and the significantly decreased Blautia, Clostridium IV, Bacteroides, Eubacterium, Clostridium XVIII, and Mogibacterium in the SA and A groups were related to the reduced caecal lactate and LPS contents, the decreased inflammatory reaction, and the improved healthy hepatic condition of yak calves. In conclusion, milk replacer supplemented with alfalfa hay and starter feed is recommended during preweaning to improve yak calf health and growth because this regimen promotes the growth and maintains the immune homeostasis of yak calves.


Assuntos
Microbiota , Rúmen , Ração Animal/análise , Animais , Peso Corporal , Bovinos , Ceco , Dieta/veterinária , Suplementos Nutricionais , Fermentação , Masculino , Medicago sativa , RNA Ribossômico 16S/metabolismo , Rúmen/metabolismo , Desmame
18.
Int J Mol Sci ; 22(3)2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33572867

RESUMO

The ribosome CAR interaction surface is hypothesized to provide a layer of translation regulation through hydrogen-bonding to the +1 mRNA codon that is next to enter the ribosome A site during translocation. The CAR surface consists of three residues, 16S/18S rRNA C1054, A1196 (E. coli 16S numbering), and R146 of yeast ribosomal protein Rps3. R146 can be methylated by the Sfm1 methyltransferase which is downregulated in stressed cells. Through molecular dynamics analysis, we show here that methylation of R146 compromises the integrity of CAR by reducing the cation-pi stacking of the R146 guanidinium group with A1196, leading to reduced CAR hydrogen-bonding with the +1 codon. We propose that ribosomes assembled under stressed conditions have unmethylated R146, resulting in elevated CAR/+1 codon interactions, which tunes translation levels in response to the altered cellular context.


Assuntos
Arginina/metabolismo , RNA Mensageiro/metabolismo , Ribossomos/metabolismo , Saccharomyces cerevisiae/metabolismo , Ligação de Hidrogênio , Metilação , Modelos Moleculares , RNA Ribossômico 16S/metabolismo , RNA Ribossômico 18S/metabolismo , Proteínas Ribossômicas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
19.
PLoS Comput Biol ; 17(2): e1008782, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33617526

RESUMO

Approximately 30% of patients who have Clostridioides difficile infection (CDI) will suffer at least one incident of reinfection. While the underlying causes of CDI recurrence are poorly understood, interactions between C. difficile and commensal gut bacteria are thought to play an important role. In this study, an in silico pipeline was used to process 16S rRNA gene amplicon sequence data of 225 stool samples from 93 CDI patients into sample-specific models of bacterial community metabolism. Clustered metabolite production rates generated from post-diagnosis samples generated a high Enterobacteriaceae abundance cluster containing disproportionately large numbers of recurrent samples and patients. This cluster was predicted to have significantly reduced capabilities for secondary bile acid synthesis but elevated capabilities for aromatic amino acid catabolism. When applied to 16S sequence data of 40 samples from fecal microbiota transplantation (FMT) patients suffering from recurrent CDI and their stool donors, the community modeling method generated a high Enterobacteriaceae abundance cluster with a disproportionate large number of pre-FMT samples. This cluster also was predicted to exhibit reduced secondary bile acid synthesis and elevated aromatic amino acid catabolism. Collectively, these in silico predictions suggest that Enterobacteriaceae may create a gut environment favorable for C. difficile spore germination and/or toxin synthesis.


Assuntos
Clostridioides difficile , Infecções por Clostridium/fisiopatologia , Microbioma Gastrointestinal , RNA Ribossômico 16S/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bactérias/genética , Ácidos e Sais Biliares/metabolismo , Infecções por Clostridium/metabolismo , Análise por Conglomerados , Simulação por Computador , Enterobacteriaceae , Transplante de Microbiota Fecal , Fezes/microbiologia , Humanos , Pessoa de Meia-Idade , Análise de Componente Principal , Reinfecção , Reprodutibilidade dos Testes , Adulto Jovem
20.
Biomolecules ; 11(2)2021 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-33578957

RESUMO

This work reports an eco-friendly synthesis of silver nanoparticles (AgNPs) using endophytic bacteria, Cytobacillus firmus isolated from the stem bark of Terminalia arjuna. The synthesis of AgNPs was confirmed by visual observation as a change in color of the bacterial solution impregnated with silver. Further, the morphology of the AgNPs, average size, and presence of elemental silver were characterized by UV-Visible spectroscopy, scanning electron microscopy, and dynamic light scattering spectroscopy. The roles of endophytic secondary metabolites in the metal reduction, stabilization, and capping of silver nanoparticles were studied by qualitative FTIR spectral peaks. The antimicrobial ability of AgNPs was evaluated against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria and pearl millet blast disease-causing fungi (Magnoporthe grisea). The biosynthesized AgNPs showed good antibacterial and antifungal activities. AgNPs effectively inhibited the bacterial growth in a dose-dependent manner and presented as good antifungal agents towards the growth of Magnoporthe grisea.


Assuntos
Anti-Infecciosos/farmacologia , Bacillaceae/metabolismo , Química Verde , Nanopartículas Metálicas/química , Prata/química , Terminalia/metabolismo , Plaquetas/citologia , Sobrevivência Celular , Eritrócitos/citologia , Escherichia coli , Hemólise , Humanos , Luz , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência , Casca de Planta , Pyricularia grisea , RNA Ribossômico 16S/metabolismo , Espalhamento de Radiação , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus , Difração de Raios X
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