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1.
Chinese Journal of Biotechnology ; (12): 448-460, 2021.
Article in Chinese | WPRIM | ID: wpr-878574

ABSTRACT

Resource utilization is an effective way to cope with the rapid increase of kitchen waste and excess sludge, and volatile fatty acids produced by anaerobic fermentation is an important way of recycling organic waste. However, the single substrate limits the efficient production of volatile fatty acids. In recent years, volatile fatty acids produced by anaerobic co-fermentation using different substrates has been widely studied and applied. In this paper, we analyze the characteristics of fermentation to produce acid using kitchen waste and excess sludge alone or mixture. Influences of environmental factors and microbial community structure on the type and yield of volatile fatty acids in the anaerobic fermentation system are discussed in detail. Moreover, we propose future research directions, to provide a reference for recycling kitchen waste and excess sludge.


Subject(s)
Anaerobiosis , Bioreactors , Fatty Acids, Volatile , Fermentation , Hydrogen-Ion Concentration , Microbiota , Organic Chemicals , Sewage
2.
Chinese Journal of Biotechnology ; (12): 149-162, 2021.
Article in Chinese | WPRIM | ID: wpr-878550

ABSTRACT

Polyhydroxyalkanoates (PHA) synthesis by activated sludge using volatile fatty acids (VFAs) in fermentation liquid of excess sludge as carbon source is a hotspot in the field of environmental biotechnology. However, there is no unified conclusion on the effects of non-VFAs, mainly dissolved organic matter (DOM), on PHA production. Thus, this critical review mainly introduces the main characteristics and common analysis methods of DOM in anaerobic fermentation liquid. The effects of DOM on PHA production are analyzed from the aspects of microbiology, metabolic regulation and sludge properties. The results of different studies showed that high concentration of DOM is bad for PHA production, but an appropriate amount of DOM is conducive to the stability of sludge properties, reducing the final PHA purification cost. Finally, suitable strategies were proposed to regulate the PHA synthesis by activated sludge with DOM for PHA production by anaerobic fermentation liquid.


Subject(s)
Anaerobiosis , Bioreactors , Fatty Acids, Volatile , Fermentation , Polyhydroxyalkanoates , Sewage
3.
Acta Physiologica Sinica ; (6): 42-50, 2021.
Article in Chinese | WPRIM | ID: wpr-878234

ABSTRACT

This study was designed to evaluate the role of short-chain fatty acid butyrate acid on intestinal morphology and function, and atherosclerotic plaque formation in apolipoprotein E-knockout (ApoE


Subject(s)
Animals , Apolipoproteins E/genetics , Atherosclerosis/prevention & control , Butyrates/pharmacology , Caco-2 Cells , Diet, High-Fat/adverse effects , Fatty Acids, Volatile , Humans , Mice , Mice, Inbred C57BL , Mice, Knockout , Plaque, Atherosclerotic
4.
Article in English | WPRIM | ID: wpr-922383

ABSTRACT

OBJECTIVES@#To study the effect of the course of treatment with broad-spectrum antibiotics on intestinal flora and short-chain fatty acids (SCFAs) in feces of very low birth weight (VLBW) infants.@*METHODS@#A total of 29 VLBW infants who were admitted to the Neonatal Diagnosis and Treatment Center of Children's Hospital Affiliated to Chongqing Medical University from June to December 2020 were enrolled as subjects for this prospective study. According to the course of treatment with broad-spectrum antibiotics, they were divided into two groups: ≤7 days (@*RESULTS@#There was a significant reduction in Chao index of the intestinal flora in the ≤7 days group and the >7 days group from week 2 to week 4 (@*CONCLUSIONS@#The course of treatment with broad-spectrum antibiotics can affect the abundance, colonization, and evolution of intestinal flora and the content of their metabolites SCFAs in VLBW infants. The indication and treatment course for broad-spectrum antibiotics should be strictly controlled in clinical practice.


Subject(s)
Anti-Bacterial Agents , Child , Fatty Acids, Volatile , Feces , Gastrointestinal Microbiome , Humans , Infant , Infant, Newborn , Infant, Very Low Birth Weight , Prospective Studies
5.
Arq. bras. med. vet. zootec. (Online) ; 72(6): 2045-2052, Nov.-Dec. 2020. tab
Article in English | LILACS, VETINDEX | ID: biblio-1142299

ABSTRACT

The present study aimed to morphometrically evaluate the ruminal mucosa and ruminal fluid characteristics of Santa Inês sheep fed different levels of spineless cactus as a replacement for Tifton grass hay. A total of 32 intact male Santa Inês sheep, approximately 180 days old and with a mean weight of 32.0±1.6kg, were studied in a completely randomized design with four treatments and eight replicates. The morphometric measurements evaluated in the ruminal epithelium (papilla height and surface area) were significantly affected (P< 0.05) by supplementation of the diet with spineless cactus, and these effects showed increasing linear trends. Evaluations of the ruminal fluid also showed a significant increasing linear effect (P< 0.05) for ammonia and a quadratic effect for microbial protein. The inclusion of spineless cactus in the sheep diet affects the ruminal epithelium morphology, including the papilla height and surface area, and favors the absorption process in the rumen. The diet containing higher levels of spineless cactus led to maximum microbial protein production. These results characterize spineless cactus as a feasible alternative for feeding sheep during periods of drought, when the typical food source is scarce.(AU)


O presente estudo teve como objetivo avaliar morfometricamente a mucosa ruminal e as características do líquido ruminal de ovinos Santa Inês alimentados com diferentes níveis de palma forrageira como substituta do feno de capim-Tifton. Um total de 32 ovinos, machos inteiros, da raça Santa Inês, com aproximadamente 180 dias de idade e peso médio de 32,0±1,6kg, foi estudado em delineamento inteiramente ao acaso, com quatro tratamentos e oito repetições. As medidas morfométricas avaliadas no epitélio ruminal (altura e área superficial da papila) foram significativamente afetadas (P<0,05) pela suplementação da dieta com palma forrageira, e esses efeitos mostraram tendências lineares crescentes. As avaliações do fluido ruminal também mostraram um efeito linear crescente significativo (P<0,05) para a amônia e um efeito quadrático para a proteína microbiana. A inclusão de palma forrageira na dieta de ovinos afeta a morfologia do epitélio ruminal, englobando a altura e a área da papila, e favorece o processo de absorção no rúmen. A dieta contendo níveis mais altos de palma forrageira levou à produção máxima de proteína microbiana. Esses resultados caracterizam a palma forrageira como uma alternativa viável para a alimentação de ovelhas durante períodos de seca, quando a fonte típica de alimento é escassa.(AU)


Subject(s)
Animals , Male , Rumen/anatomy & histology , Sheep/anatomy & histology , Opuntia/chemistry , Mucous Membrane/anatomy & histology , Fatty Acids, Volatile
6.
Electron. j. biotechnol ; 47: 29-35, sept. 2020. tab, graf
Article in English | LILACS | ID: biblio-1253015

ABSTRACT

BACKGROUND: Salep is obtained by grinding dried orchid tubers and used as a valuable ingredient in the food industry. Because of the glucomannan content of salep, it is thought to have prebiotic potential. However, there is little information in studies concerning the fermentation characteristics and potential prebiotic properties of salep. The objective of this study was to investigate the effect of salep on bifidobacterial growth by measuring the highest optical density (OD), calculating the specific growth rates, and determining the production of lactic acid and short-chain fatty acids (acetic, propionic, and butyric acid) as a result of bacterial fermentation. RESULT: The OD and pH values obtained in this study showed that salep was utilized as a source of assimilable carbon and energy by the Bifidobacterium species (BS). All Bifidobacterium strains produced lactic, acetic, propionic, and butyric acid, indicating that salep is readily fermented by these bacteria. Salep at 1% (w/v) showed a similar effect on bifidobacterial growth as that promoted by 1% (w/v) glucose used as a traditional carbon source. CONCLUSIONS: Bifidobacterium species can develop in media containing salep as well as in glucose and exhibit the potential to be used as new sources of prebiotics.


Subject(s)
Powders/metabolism , Bifidobacterium/growth & development , Bifidobacterium/metabolism , Fatty Acids, Volatile/biosynthesis , Propionates/analysis , Propionates/metabolism , Food Industry , Acetic Acid/analysis , Acetic Acid/metabolism , Lactic Acid/analysis , Lactic Acid/metabolism , Probiotics , Butyric Acid/analysis , Butyric Acid/metabolism , Fatty Acids, Volatile/analysis , Prebiotics , Fermentation , Hydrogen-Ion Concentration
7.
Chinese Journal of Biotechnology ; (12): 1190-1197, 2020.
Article in Chinese | WPRIM | ID: wpr-826859

ABSTRACT

Clostridia inhabiting in jiupei and pit mud plays key roles in the formation of flavour during the fermentation process of Luzhou-flavour baijiu. However, the differences of Clostridial communities between jiupei and pit mud remains unclear. Here, the species assembly, succession, and metabolic capacity of Clostridial communities between jiupei and pit mud were analysed by high-throughput sequencing and pure culture approaches. The ratio of Clostridial biomass to bacterial biomass in the pit mud was relatively stable (71.5%-91.2%) throughout the fermentation process. However, it varied widely in jiupei (0.9%-36.5%). The dominant Clostridial bacteria in jiupei were Clostridium (19.9%), Sedimentibacter (8.8%), and Hydrogenispora (7.2%), while Hydrogenispora (57.2%), Sedimentibacter (5.4%), and Caproiciproducens (4.9%) dominated in the Clostridial communities in pit mud. The structures of Clostridial community in pit mud and jiupei were significantly different (P=0.001) throughout fermentation. Isolated Clostridial strains showed different metabolic capacities of volatile fatty acids in pure culture. Spatial and temporal heterogeneity of Clostridial communities existed in the baijiu fermentation pit, which was closely related to the main flavour components of Luzhou-flavour baijiu.


Subject(s)
Alcoholic Beverages , Microbiology , Bacteria , Classification , Metabolism , Clostridium , Physiology , Fatty Acids, Volatile , Metabolism , Fermentation , Food Microbiology
8.
Article in English | WPRIM | ID: wpr-762177

ABSTRACT

PURPOSE: Alterations in the intestinal microbiota in early life affects the development of atopic dermatitis (AD) in humans. This study aimed to further investigate the effects of gut dysbiosis in early life in an ovalbumin (OVA)-induced mouse model of AD. METHODS: The AD mouse model was developed by serial OVA sensitization and mice were treated with an antibiotic cocktail in their drinking water for 2 weeks before primary sensitization. Probiotics (Lactobacillus rhamnosus, 1 × 10⁹ CFU) or 100 µL of fresh fecal supernatant were orally administered daily from 1 week before the first sensitization until the end of the study. RESULTS: The AD mice which received antibiotics had significantly aggravated phenotypes, including clinical score, transepidermal water loss, and histopathology, compared to those treated with healthy feces or probiotics. Total systemic immunoglobulin E production and skin interleukin (IL) 4 levels were significantly increased in the antibiotic-treated mice compared to the other groups. Antibiotic treatment also increased the levels of IL17 and group 3 innate lymphoid cells (ILC3) in the gut and significantly suppressed the production of short-chain fatty acids (SCFAs) and decreased the number FOXP3⁺ cells. CONCLUSIONS: Our results suggest that the status of the gut microbiota in early life in the mouse may play a crucial role in AD development through intestinal SCFA production through regulate the numbers of CD4⁺IL17⁺/CD4⁺FOXP3⁺ regulatory T cells and ILC3s.


Subject(s)
Animals , Anti-Bacterial Agents , Cytokines , Dermatitis, Atopic , Drinking Water , Dysbiosis , Fatty Acids , Fatty Acids, Volatile , Feces , Gastrointestinal Microbiome , Humans , Immunoglobulin E , Immunoglobulins , Interleukins , Intestines , Lymphocytes , Mice , Microbiota , Ovalbumin , Ovum , Phenotype , Probiotics , Skin , T-Lymphocytes, Regulatory , Water
9.
Article in English | WPRIM | ID: wpr-785338

ABSTRACT

PURPOSE: The roles of gut microbiota on the natural course of atopic dermatitis (AD) are not yet fully understood. We investigated whether the composition and function of gut microbiota and short-chain fatty acids (SCFAs) at 6 months of age could affect the natural course of AD up to 24 months in early childhood.METHODS: Fecal samples from 132 infants were analyzed using pyrosequencing, including 84 healthy controls, 22 transient AD and 26 persistent AD subjects from the Cohort for Childhood Origin of Asthma and Allergic Diseases (COCOA) birth cohort. The functional profile of the gut microbiome was analyzed by whole-metagenome sequencing. SCFAs were measured using gas chromatography-mass spectrometry.RESULTS: Low levels of Streptococcus and high amounts of Akkermansia were evident in transient AD cases, and low Clostridium, Akkermansia and high Streptococcus were found in children with persistent AD. The relative abundance of Streptococcus positively correlated with scoring of AD (SCORAD) score, whereas that of Clostridium negatively correlated with SCORAD score. The persistent AD group showed decreased gut microbial functional genes related to oxidative phosphorylation compared with healthy controls. Butyrate and valerate levels were lower in transient AD infants compared with healthy and persistent AD infants.CONCLUSIONS: Compositions, functions and metabolites of the early gut microbiome are related to natural courses of AD in infants.


Subject(s)
Asthma , Butyrates , Child , Clostridium , Cohort Studies , Dermatitis, Atopic , Fatty Acids, Volatile , Gas Chromatography-Mass Spectrometry , Gastrointestinal Microbiome , Humans , Infant , Metabolomics , Metagenome , Oxidative Phosphorylation , Parturition , Streptococcus
10.
Electron. j. biotechnol ; 39: 61-66, may. 2019. graf, tab
Article in English | LILACS | ID: biblio-1052032

ABSTRACT

BACKGROUND: Triclosan (TCS) is an antimicrobial agent widely used in health care and consumer products. This compound is present in sludge of wastewater treatment plants (WWTPs), and because of its bactericidal characteristics, it can inhibit the methanogenic activity in anaerobic digestion (AD) technology. The aim of this study was to evaluate the toxic effects of TCS on the methanogenic activity. RESULTS: Batch anaerobic reactors were used with TCS concentrations of 7.8, 15.7, 23.5, and 31.4 mg/L. These assays consisted in three successive feedings (I, II, and III), wherein the sludge was exposed to each TCS concentration and volatile fatty acid (VFA) substrate. For evaluation of the residual sludge activity during feeding III, only VFA was used. The results showed that the increase in TCS concentrations correlated with the reduction in methane (CH4) production. In this case, the minimum values were achieved for TCS concentration of 31.4 mg/L with CH4 levels between 101.9 and 245.3 during feedings I, II, and III. Regarding the effect of TCS on VFA consumption, an inhibitory effect was detected for TCS concentrations of 23.5 and 31.4 mg/L, with concentrations of acetic, butyric, and propionic acids at the end of the assay (37 d) between 153.6 and 206.8, 62.5 and 60.1, and 93.4 and 110 mg/L, respectively. Regarding the removal of TCS during AD, these values were above 47%. Conclusion: TCS is an inhibitor of methanogenic activity with a decrease between 63 and 70% during the different feedings. The CH4 production was not recovered during feeding III, with inhibition percentages of 21­72%.


Subject(s)
Triclosan/toxicity , Anaerobic Digestion , Methane/metabolism , Anti-Infective Agents/toxicity , Sewage , Wastewater Treatment Plants , Chromatography, High Pressure Liquid , Fatty Acids, Volatile , Anaerobiosis
11.
Article in English | WPRIM | ID: wpr-740764

ABSTRACT

BACKGROUND/AIMS: Probiotics are expected to confer benefits on patients with constipation, but how probiotics act on constipated patients with variable stool consistencies remains unclear. We investigated the effect of Lactobacillus casei strain Shirota (LcS) on constipation-related symptoms, especially stool consistency, of constipated patients. METHODS: Constipated patients meeting the Rome III criteria were divided into 3 groups according to the Bristol Stool Form Scale (BSFS): hard (hard stool [HS], BSFS < 3), normal (normal stool [NS], ≤ 3 BSFS ≤ 4), and soft (soft stool [SS], 4 < BSFS ≤ 5) stools. Subjects in each group consumed a probiotic beverage containing 1010 colony-forming units of LcS daily for 28 days. RESULTS: LcS intervention significantly alleviated constipation-related symptoms and increased defecation frequency in all subjects. Four weeks of LcS supplementation softened the hard stools in HS, hardened the soft stools in SS, and did not alter the ideal stool consistency in NS. The short-chain fatty acid (SCFA) concentrations were highest in SS, followed by NS and HS. LcS intervention increased the stool SCFA levels in HS but reduced or did not alter the levels in NS and SS. LcS intervention increased the Pseudobutyrivibrio and Roseburia abundances in HS and decreased the Pseudobutyrivibrio abundance in SS. CONCLUSIONS: LcS supplementation improved the constipation-related symptoms in constipated subjects. Differences in baseline stool consistency could result in different anti-constipation effects of LcS intervention. LcS balanced the stool consistency—softened the HS and hardened the SS. These effects could be associated with modulation of the gut microbiota and SCFA production.


Subject(s)
Beverages , China , Constipation , Defecation , Fatty Acids, Volatile , Gastrointestinal Microbiome , Humans , Lactobacillus casei , Lactobacillus , Probiotics , Stem Cells
12.
Immune Network ; : e9-2019.
Article in English | WPRIM | ID: wpr-740219

ABSTRACT

Staphylococcus aureus, a Gram-positive pathogen, can cause severe inflammation in humans, leading to various life-threatening diseases. The lipoprotein is a major virulence factor in S. aureus-induced infectious diseases and is responsible for excessive inflammatory mediators such as nitric oxide (NO). Short-chain fatty acids (SCFAs) including butyrate, propionate, and acetate are microbial metabolites in the gut that are known to have anti-inflammatory effects in the host. In this study, we investigated the effects of SCFAs on S. aureus lipoprotein (Sa.LPP)-induced NO production in mouse macrophages. Butyrate and propionate, but not acetate, inhibited Sa.LPP-induced production of NO in RAW 264.7 cells and bone marrow-derived macrophages. Butyrate and propionate inhibited Sa.LPP-induced expression of inducible NO synthase (iNOS). However, acetate did not show such effects under the same conditions. Furthermore, butyrate and propionate, but not acetate, inhibited Sa.LPP-induced activation of NF-κB, expression of IFN-β, and phosphorylation of STAT1, which are essential for inducing transcription of iNOS in macrophages. In addition, butyrate and propionate induced histone acetylation at lysine residues in the presence of Sa.LPP in RAW 264.7 cells. Moreover, Sa.LPP-induced NO production was decreased by histone deacetylase (HDAC) inhibitors. Collectively, these results suggest that butyrate and propionate ameliorate the inflammatory responses caused by S. aureus through the inhibition of NF-κB, IFN-β/STAT1, and HDAC, resulting in attenuated NO production in macrophages.


Subject(s)
Acetylation , Animals , Butyrates , Communicable Diseases , Diethylpropion , Fatty Acids, Volatile , Histone Deacetylase Inhibitors , Histone Deacetylases , Histones , Humans , Inflammation , Lipoproteins , Lysine , Macrophages , Mice , Nitric Oxide Synthase , Nitric Oxide , Phosphorylation , Staphylococcus aureus , Virulence
13.
Article in English | WPRIM | ID: wpr-773408

ABSTRACT

OBJECTIVE@#To investigate the molecular mechanisms of the adverse effects of exposure to sulfamonomethoxin (SMM) in pregnancy on the neurobehavioral development of male offspring.@*METHODS@#Pregnant mice were randomly divided into four groups: control- (normal saline), low- [10 mg/(kg•day)], middle- [50 mg/(kg•day)], and high-dose [200 mg/(kg•day)] groups, which received SMM by gavage daily during gestational days 1-18. We measured the levels of short-chain fatty acids (SCFAs) in feces from dams and male pups. Furthermore, we analyzed the mRNA and protein levels of genes involved in the mammalian target of rapamycin (mTOR) pathway in the hippocampus of male pups by RT-PCR or Western blotting.@*RESULTS@#Fecal SCFA concentrations were significantly decreased in dams. Moreover, the production of individual fecal SCFAs was unbalanced, with a tendency for an increased level of total fecal SCFAs in male pups on postnatal day (PND) 22 and 56. Furthermore, the phosphatidylinositol 3-kinase (PI3k)/protein kinase B (AKT)/mTOR or mTOR/ribosomal protein S6 kinase 1 (S6K1)/4EBP1 signaling pathway was continuously upregulated until PND 56 in male offspring. In addition, the expression of Sepiapterin Reductase (SPR), a potential target of mTOR, was inhibited.@*CONCLUSION@#In utero exposure to SMM, persistent upregulation of the hippocampal mTOR pathway related to dysfunction of the gut (SCFA)-brain axis may contribute to cognitive deficits in male offspring.


Subject(s)
Alcohol Oxidoreductases , Metabolism , Animals , Anti-Infective Agents , Toxicity , Fatty Acids, Volatile , Feces , Chemistry , Female , Hippocampus , Metabolism , Male , Memory , Mice, Inbred ICR , Pregnancy , Prenatal Exposure Delayed Effects , Sulfamonomethoxine , Toxicity , TOR Serine-Threonine Kinases , Metabolism
14.
Article in Chinese | WPRIM | ID: wpr-775125

ABSTRACT

OBJECTIVE@#To compare the levels of short-chain fatty acids in enterobacteria-related metabolites in feces between infants with cholestatic hepatopathy and healthy infants.@*METHODS@#Thirty infants with cholestatic hepatopathy were enrolled in this study as the disease group, while 30 healthy infants were enrolled as the control group. Fecal specimens were collected from the disease group before and after treatment and from the control group. Gas chromatography was used to quantitatively determine the content of short-chain fatty acids in the feces of both groups including acetic acid, propionic acid, butyric acid, isobutyric acid, and isovaleric acid.@*RESULTS@#There were no significant differences in the concentrations of acetic acid and propionic acid between the control and disease groups before and after treatment, as well as no significant changes in the two markers in the disease group after treatment (P>0.05). The disease group had a significantly increased concentration of butyric acid after treatment (P<0.05). The concentrations of isobutyric acid and isovaleric acid in the control group were significantly higher than those in the disease group before and after treatment (P<0.05).@*CONCLUSIONS@#Intestinal protein metabolites in infants with cholestatic hepatopathy are significantly different from those in healthy infants, whereas there is no significant difference with respect to carbohydrate metabolites.


Subject(s)
Acetates , Butyric Acid , Enterobacteriaceae , Fatty Acids, Volatile , Feces , Humans , Infant
15.
Chinese Medical Journal ; (24): 411-419, 2019.
Article in English | WPRIM | ID: wpr-774822

ABSTRACT

BACKGROUND@#Vasovagal syncope (VVS) is common in children and greatly affect both physical and mental health. But the mechanisms have not been completely explained. This study was designed to analyze the gut microbiota in children with VVS and explore its clinical significance.@*METHODS@#Fecal samples from 20 VVS children and 20 matched controls were collected, and the microbiota were analyzed by 16S rRNA gene sequencing. The diversity and microbiota compositions of the VVS cases and controls were compared with the independent sample t test or Mann-Whitney U test. The correlation between the predominant bacteria and clinical symptoms was analyzed using Pearson or Spearman correlation test.@*RESULTS@#No significant differences in diversity were evident between VVS and controls (P > 0.05). At the family level, the relative abundance of Ruminococcaceae was significantly higher in VVS children than in controls (median [Q1, Q3]: 22.10% [16.89%, 27.36%] vs. 13.92% [10.31%, 20.18%], Z = -2.40, P  4, P < 0.05). The relative abundance of Ruminococcaceae in VVS patients was positively correlated with the frequency of syncope (r = 0.616, P < 0.01). In terms of its correlation with hemodynamics, we showed that relative abundance of Ruminococcaceae was negatively correlated with the systolic and diastolic pressure reduction at the positive response in head-up tilt test (HUTT; r = -0.489 and -0.448, all P < 0.05), but was positively correlated with the mean pressure drop and decline rate (r = 0.489 and 0.467, all P < 0.05) as well as diastolic pressure drop and decline rate at the HUTT positive response (r = 0.579 and 0.589, all P < 0.01) in VVS patients.@*CONCLUSION@#Ruminococcaceae was the predominant gut bacteria and was associated with the clinical symptoms and hemodynamics of VVS, suggesting that gut microbiota might be involved in the development of VVS.


Subject(s)
Adolescent , Child , Child, Preschool , Fatty Acids, Volatile , Metabolism , Female , Gastrointestinal Microbiome , Humans , Male , Ruminococcus , Physiology , Syncope, Vasovagal , Microbiology
16.
Braz. j. microbiol ; 49(4): 770-776, Oct.-Dec. 2018. tab, graf
Article in English | LILACS | ID: biblio-974307

ABSTRACT

ABSTRACT Anaerobic digestion is important for the management of livestock manure with high ammonia level. Although ammonia effects on anaerobic digestion have been comprehensively studied, the molecular mechanism underlying ammonia inhibition still remains elusive. In this study, based on metatranscriptomic analysis, the transcriptional profile of microbial community in anaerobic digestion under low (1500 mg L-1) and high NH4 + (5000 mg L-1) concentrations, respectively, were revealed. The results showed that high NH4 + concentrations significantly inhibited methane production but facilitated the accumulations of volatile fatty acids. The expression of methanogenic pathway was significantly inhibited by high NH4 + concentration but most of the other pathways were not significantly affected. Furthermore, the expressions of methanogenic genes which encode acetyl-CoA decarbonylase and methyl-coenzyme M reductase were significantly inhibited by high NH4 + concentration. The inhibition of the co-expressions of the genes which encode acetyl-CoA decarbonylase was observed. Some genes involved in the pathways of aminoacyl-tRNA biosynthesis and ribosome were highly expressed under high NH4 + concentration. Consequently, the ammonia inhibition on anaerobic digestion mainly focused on methanogenic process by suppressing the expressions of genes which encode acetyl-CoA decarbonylase and methyl-coenzyme M reductase. This study improved the accuracy and depth of understanding ammonia inhibition on anaerobic digestion.


Subject(s)
Bacteria/genetics , Bacteria/metabolism , Ammonia/metabolism , Bacteria/isolation & purification , Bacteria/classification , Transcription, Genetic , Bioreactors/microbiology , Fatty Acids, Volatile/metabolism , Microbiota , Anaerobiosis , Methane/metabolism
17.
Braz. j. microbiol ; 49(supl.1): 101-106, 2018. tab, graf
Article in English | LILACS | ID: biblio-974326

ABSTRACT

Abstract In the Southern Hemisphere, ruminants are mostly raised in grazing systems where animals consume forage and are supplemented with low amounts of concentrates. Concentrates are usually given separately and are rapidly ingested. This practice leads to changing rumen environment conditions during the day, may alter the rumen microbial metabolism and could affect host performance. The native ruminal Prevotella bryantii strain 3C5 was administered every 48 h to wethers under experimental conditions simulating Southern-Hemisphere feeding to evaluate its potential as a rumen fermentation modulator. The inoculum potential was assessed on day 17. The ammonia nitrogen (NH3-N), volatile fatty acids and ruminal pH were monitored on a 24-h basis 19 days after the beginning of the experiment, and the microbial community structure was assessed by pyrosequencing. The administration of P. bryantii modified the fermentation products and daily pH values compared to the control. The NH3-N concentration in the rumen of treated animals was significantly higher than that of the untreated animals. Modification of the ruminal environment and fermentation pathways was achieved without altering the general structure of the microbial community or the potential methane production. P. bryantii 3C5 could be considered in potential probiotic formulations for ruminants in semi-intensive systems.


Subject(s)
Animals , Male , Rumen/microbiology , Prevotella/metabolism , Rumen/metabolism , Rumen/chemistry , Sheep , Prevotella/genetics , Digestion , Fatty Acids, Volatile/metabolism , Fermentation , Ammonia/metabolism , Hydrogen-Ion Concentration , Models, Biological
18.
Immune Network ; : e15-2018.
Article in English | WPRIM | ID: wpr-740197

ABSTRACT

Emerging evidence demonstrates that the microbiota plays an essential role in shaping the development and function of host immune responses. A variety of environmental stimuli, including foods and commensals, are recognized by the host through the epithelium, acting as a physical barrier. Two allergic diseases, atopic dermatitis and food allergy, are closely linked to the microbiota, because inflammatory responses occur on the epidermal border. The microbiota generates metabolites such as short-chain fatty acids and poly-γ-glutamic acid (γPGA), which can modulate host immune responses. Here, we review how microbial metabolites can regulate allergic immune responses. Furthermore, we focus on the effect of γPGA on allergic T helper (Th) 2 responses and its therapeutic application.


Subject(s)
Architectural Accessibility , Dermatitis, Atopic , Epithelium , Fatty Acids, Volatile , Food Hypersensitivity , Microbiota , Natural Killer T-Cells
19.
Article in English | WPRIM | ID: wpr-715319

ABSTRACT

Alcoholic liver disease (ALD) is a major cause of morbidity and mortality worldwide. Only 20% of heavy alcohol consumers develop alcoholic liver cirrhosis. The intestinal microbiota (IM) has been recently identified as a key player in the severity of liver injury in ALD. Common features of ALD include a decrease of gut epithelial tight junction protein expression, mucin production, and antimicrobial peptide levels. This disruption of the gut barrier, which is a prerequisite for ALD, leads to the passage of bacterial products into the blood stream (endotoxemia). Moreover, metabolites produced by bacteria, such as short chain fatty acids, volatile organic compounds (VOS), and bile acids (BA), are involved in ALD pathology. Probiotic treatment, IM transplantation, or the consumption of dietary fiber, such as pectin, which all alter the ratio of bacterial species, have been shown to improve liver injury in animal models of ALD and to be associated with an improvement in gut barrier function. Although the connections between the microbiota and the host in ALD are well established, the underlying mechanisms are still an active area of research. Targeting the microbiome through the use of prebiotic, probiotic, and postbiotic modalities could be an attractive new approach to manage ALD.


Subject(s)
Alcoholics , Bacteria , Bile Acids and Salts , Dietary Fiber , Fatty Acids, Volatile , Gastrointestinal Microbiome , Humans , Liver , Liver Cirrhosis, Alcoholic , Liver Diseases, Alcoholic , Microbiota , Models, Animal , Mortality , Mucins , Pathology , Prebiotics , Probiotics , Rivers , Tight Junctions
20.
Electron. j. biotechnol ; 28: 67-75, July. 2017.
Article in English | LILACS | ID: biblio-1015999

ABSTRACT

The increasing demand for propionic acid (PA) production and its wide applications in several industries, especially the food industry (as a preservative and satiety inducer), have led to studies on the low-cost biosynthesis of this acid. This paper gives an overview of the biotechnological aspects of PA production and introduces Propionibacterium as the most popular organism for PA production. Moreover, all process variables influencing the production yield, different simple and complex carbon sources, the metabolic pathway of production, engineered mutants with increased productivity, and modified tolerance against high concentrations of acid have been described. Furthermore, possible methods of extraction and analysis of this organic acid, several applied bioreactors, and different culture systems and substrates are introduced. It can be concluded that maximum biomass and PA production may be achieved using metabolically engineered microorganisms and analyzing the most significant factors influencing yield. To date, the maximum reported yield for PA production is 0.973 g·g-1, obtained from Propionibacterium acidipropionici in a three-electrode amperometric culture system in medium containing 0.4 mM cobalt sepulchrate. In addition, the best promising substrate for PA bioproduction may be achieved using glycerol as a carbon source in an extractive continuous fermentation. Simultaneous production of PA and vitamin B12 is suggested, and finally, the limitations of and strategies for competitive microbial production with respect to chemical process from an economical point of view are proposed and presented. Finally, some future trends for bioproduction of PA are suggested.


Subject(s)
Propionates/metabolism , Propionibacterium/metabolism , Propionates/chemistry , Vitamin B 12/biosynthesis , Carbon/metabolism , Bioreactors , Fatty Acids, Volatile/metabolism , Fermentation , Hydrogen-Ion Concentration , Nitrogen/metabolism
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