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1.
Int J Mol Sci ; 24(1)2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36614212

RESUMO

Short-chain fatty acids as well as their bacterial producers are of increasing interest in inflammatory bowel diseases. Although less studied compared to butyrate, acetate might also be of interest as it may be less toxic to epithelial cells, stimulate butyrate-producing bacteria by cross-feeding, and have anti-inflammatory and barrier-protective properties. Moreover, one of the causative factors of the probiotic potency of Saccharomyces cerevisae var. boulardii is thought to be its high acetate production. Therefore, the objective was to preclinically assess the effects of high acetate concentrations on inflammation and barrier integrity in organoid-based monolayer cultures from ulcerative colitis patients. Confluent organoid-derived colonic epithelial monolayers (n = 10) were exposed to basolateral inflammatory stimulation or control medium. After 24 h, high acetate or control medium was administered apically for an additional 48 h. Changes in TEER were measured after 48 h. Expression levels of barrier genes and inflammatory markers were determined by qPCR. Pro-inflammatory proteins in the supernatant were quantified using the MSD platform. Increased epithelial resistance was observed with high acetate administration in both inflamed and non-inflamed conditions, together with decreased expression levels of IL8 and TNFα and CLDN1. Upon high acetate administration to inflamed monolayers, upregulation of HIF1α, MUC2, and MKI67, and a decrease of the majority of pro-inflammatory cytokines was observed. In our patient-derived human epithelial cell culture model, a protective effect of high acetate administration on epithelial resistance, barrier gene expression, and inflammatory protein production was observed. These findings open up new possibilities for acetate-mediated management of barrier defects and inflammation in IBD.


Assuntos
Colite Ulcerativa , Colite , Humanos , Colite Ulcerativa/metabolismo , Mucosa Intestinal/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Butiratos/farmacologia , Acetatos/farmacologia , Acetatos/metabolismo , Organoides/metabolismo , Colite/metabolismo
2.
Water Res ; 229: 119446, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36516560

RESUMO

Ca. Accumulibacter was the predominant microorganism (relative FISH bio-abundance of 67 ± 5%) in a lab-scale sequential batch reactor that accomplished enhanced biological phosphorus removal (EBPR) while using glucose and acetate as the carbon sources (1:1 COD-based ratio). Both organic compounds were completely anaerobically consumed. The reactor's performance in terms of P/C ratio, phosphorous release and uptake, and overall kinetic and stoichiometric parameters were on the high end of the reported spectrum for EBPR systems (100:9.3 net mg phosphate removal per mg COD consumed when using glucose and acetate in a 1:1 ratio). The batch tests showed that, to the best of our knowledge, this is the first time a reactor enriched with Ca. Accumulibacter can putatively utilize glucose as the sole carbon source to biologically remove phosphate (COD:P (mg/mg) removal ratio of 100:6.3 when using only glucose). Thus, this research proposes that Ca. Accumulibacter directly anaerobically stored the fed glucose primarily as glycogen by utilizing the ATP provided via the hydrolysis of poly-P and secondarily as PHA by balancing its ATP utilization (glycogen generation) and formation (PHA storage). Alternative hypotheses are also discussed. The reported findings could challenge the conventional theories of glucose assimilation by Ca. Accumulibacter, and can be of significance for the biological removal of phosphorus from wastewaters with high contents of fermentable compounds or low VFAs.


Assuntos
Reatores Biológicos , Glucose , Glicogênio/metabolismo , Fósforo/metabolismo , Fosfatos , Carbono/metabolismo , Acetatos/metabolismo , Trifosfato de Adenosina
3.
Mol Genet Metab ; 138(1): 106966, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36528988

RESUMO

Acetyl-coenzyme A (Ac-CoA) is a core metabolite with essential roles throughout cell physiology. These functions can be classified into energetics, biosynthesis, regulation and acetylation of large and small molecules. Ac-CoA is essential for oxidative metabolism of glucose, fatty acids, most amino acids, ethanol, and of free acetate generated by endogenous metabolism or by gut bacteria. Ac-CoA cannot cross lipid bilayers, but acetyl groups from Ac-CoA can shuttle across membranes as part of carrier molecules like citrate or acetylcarnitine, or as free acetate or ketone bodies. Ac-CoA is the basic unit of lipid biosynthesis, providing essentially all of the carbon for the synthesis of fatty acids and of isoprenoid-derived compounds including cholesterol, coenzyme Q and dolichols. High levels of Ac-CoA in hepatocytes stimulate lipid biosynthesis, ketone body production and the diversion of pyruvate metabolism towards gluconeogenesis and away from oxidation; low levels exert opposite effects. Acetylation changes the properties of molecules. Acetylation is necessary for the synthesis of acetylcholine, acetylglutamate, acetylaspartate and N-acetyl amino sugars, and to metabolize/eliminate some xenobiotics. Acetylation is a major post-translational modification of proteins. Different types of protein acetylation occur. The most-studied form occurs at the epsilon nitrogen of lysine residues. In histones, lysine acetylation can alter gene transcription. Acetylation of other proteins has diverse, often incompletely-documented effects. Inborn errors related to Ac-CoA feature a broad spectrum of metabolic, neurological and other features. To date, a small number of studies of animals with inborn errors of CoA thioesters has included direct measurement of acyl-CoAs. These studies have shown that low levels of tissue Ac-CoA correlate with the development of clinical signs, hinting that shortage of Ac-CoA may be a recurrent theme in these conditions. Low levels of Ac-CoA could potentially disrupt any of its roles.


Assuntos
Acetatos , Lisina , Animais , Acetilcoenzima A/metabolismo , Lisina/metabolismo , Acetilação , Acetatos/metabolismo , Ácidos Graxos
4.
Metab Eng ; 75: 110-118, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36494025

RESUMO

Medium-chain-length fatty alcohols have broad applications in the surfactant, lubricant, and cosmetic industries. Their acetate esters are widely used as flavoring and fragrance substances. Pseudomonas putida KT2440 is a promising chassis for fatty alcohol and ester production at the industrial scale due to its robustness, versatility, and high oxidative capacity. However, P. putida has also numerous native alcohol dehydrogenases, which lead to the degradation of these alcohols and thereby hinder its use as an effective biocatalyst. Therefore, to harness its capacity as a producer, we constructed two engineered strains (WTΔpedFΔadhP, GN346ΔadhP) incapable of growing on mcl-fatty alcohols by deleting either a cytochrome c oxidase PedF and a short-chain alcohol dehydrogenase AdhP in P. putida or AdhP in P. putida GN346. Carboxylic acid reductase, phosphopantetheinyl transferase, and alcohol acetyltransferase were expressed in the engineered P. putida strains to produce hexyl acetate. Overexpression of transporters further increased 1-hexanol and hexyl acetate production. The optimal strain G23E-MPAscTP produced 93.8 mg/L 1-hexanol and 160.5 mg/L hexyl acetate, with a yield of 63.1%. The engineered strain is applicable for C6-C10 fatty alcohols and their acetate ester production. This study lays a foundation for P. putida being used as a microbial cell factory for sustainable synthesis of a broad range of products based on medium-chain-length fatty alcohols.


Assuntos
Pseudomonas putida , Pseudomonas putida/genética , Pseudomonas putida/metabolismo , Ácidos Graxos/genética , Ácidos Graxos/metabolismo , Engenharia Metabólica , Ésteres/metabolismo , Álcoois Graxos/metabolismo , Acetatos/metabolismo
5.
PeerJ ; 10: e14309, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36536626

RESUMO

Mulberry flavonoids can modulate the composition of rumen microbiota in ruminants to improve nutrient digestibility, owing to their strong biological activities. This study aimed to explore the effect of mulberry leaf flavonoids (MLF) on rumen bacteria, fermentation kinetics, and metagenomic functional profile in water buffalo. Forty buffaloes (4 ± 1 lactations) with almost same body weight (av. 600 ± 50 Kg) and days in milk (90 ± 20 d) were randomly allocated to four treatments having different levels of MLF: 0 g/d (control), 15 g/d (MLF15), 30 g/d (MLF30), and 45 g/d (MLF45) supplemented in a basal diet. After 35 days of supplementation, rumen contents were collected to determine rumen fermentation parameters. The 16S rRNA gene sequencing was performed to elucidate rumen bacteria composition. The obtained taxonomic data were analyzed to explore the rumen bacteriome and predict the associated gene functions and metabolic pathways. Results demonstrated a linear increase (p < 0.01) in rumen acetate, propionate, and total VFAs in the MLF45 group as compared to control. No effect of treatment was observed on rumen pH and butyrate contents. Acetate to propionate ratio in the MLF45 group linearly and quadratically decreased (p = 0.001) as compared to MLF15 and control groups. Similarly, MLF45 linearly increased (p < 0.05) the microbial protein (MCP) and NH3-N as compared to other treatments. Treatment adversely affected (p < 0.01) almost all alpha diversity parameters of rumen bacteria except Simpson index. MLF promoted the abundance of Proteobacteria while reducing the relative abundances of Actinobacteria, Acidobacteria, Chloroflexi, and Patescibacteria. The MLF supplementation tended to substantially reduce (0.05 < p < 0.1) the abundance of Actinobacteria, and Patescibacteria while completely eliminating Acidobacteria (p = 0.029), Chloroflexi (p = 0.059), and Gemmatimonadetes (p = 0.03) indicating the negative effect of flavonoids on the growth of these bacteria. However, MLF45 tended to substantially increase (p = 0.07) the abundance (~21.5%) of Acetobacter. The MLF treatment exhibited negative effect on five genera by significantly reducing (Sphingomonas) or eliminating (Arthobactor, unclassified_c__Actinobacteria, norank_c__Subgroup_6, norank_o__Saccharimonadales, and Nocardioides) them from the rumen microbiota. Pearson correlation analysis revealed 3, 5 and 23 positive correlations of rumen bacteria with milk yield, rumen fermentation and serum antioxidant parameters, respectively. A positive correlation of MCP was observed with three bacterial genera (Acetobacter, Enterobacter, and Klebsiella). The relative abundance of Pseudobutyrivibrio and Empedobacter also showed a positive correlation with the ruminal acetate and propionate. The present study indicated 45 g/d as an appropriate dose of MLF which modulated rumen bacteria and its functional profile in water buffalo.


Assuntos
Búfalos , Morus , Animais , Feminino , Acetatos/metabolismo , Bactérias , Búfalos/genética , Fermentação , Morus/genética , Propionatos/metabolismo , RNA Ribossômico 16S/genética , Rúmen
6.
Int J Mol Sci ; 23(20)2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36293284

RESUMO

Altitude is the main external environmental pressure affecting the production performance of Tibetan sheep, and the adaptive evolution of many years has formed a certain response mechanism. However, there are few reports on the response of ruminal microbiota and host genomes of Tibetan sheep to high-altitude environments. Here, we conducted an integrated analysis of volatile fatty acids (VFAs), microbial diversity (16S rRNA), epithelial morphology, and epithelial transcriptome in the rumen of Tibetan sheep at different altitudes to understand the changes in ruminal microbiota-host interaction in response to high altitude. The differences in the nutritional quality of forage at different altitudes, especially the differences in fiber content (ADF/NDF), led to changes in rumen VFAs of Tibetan sheep, in which the A/P value (acetic acid/propionic acid) was significantly decreased (p < 0.05). In addition, the concentrations of IgA and IgG in Middle-altitude (MA) and High-altitude Tibetan sheep (HA) were significantly increased (p < 0.05), while the concentrations of IgM were significantly increased in MA (p < 0.05). Morphological results showed that the width of the rumen papilla and the thickness of the basal layer increased significantly in HA Tibetan sheep (p < 0.05). The 16S rRNA analysis found that the rumen microbial diversity of Tibetan sheep gradually decreased with increasing altitude, and there were some differences in phylum- and genus-level microbes at the three altitudes. RDA analysis found that the abundance of the Rikenellaceae RC9 gut group and the Ruminococcaceae NK4A214 group increased with altitudes. Furthermore, a functional analysis of the KEGG microbial database found the "lipid metabolism" function of HA Tibetan sheep to be significantly enriched. WGCNA revealed that five gene modules were enriched in "energy production and conversion", "lipid transport and metabolism", and "defense mechanisms", and cooperated with microbiota to regulate rumen fermentation and epithelial immune barrier function, so as to improve the metabolism and immune level of Tibetan sheep at high altitude.


Assuntos
Microbiota , Rúmen , Ovinos , Animais , Rúmen/química , Propionatos/metabolismo , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Altitude , Interações entre Hospedeiro e Microrganismos , Tibet , Ácidos Graxos Voláteis/metabolismo , Acetatos/metabolismo , Imunoglobulina A/metabolismo , Imunoglobulina G/metabolismo , Imunoglobulina M/metabolismo
7.
Food Res Int ; 161: 111763, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36192929

RESUMO

Higher alcohols (HAs) and acetate esters (AEs) produced by yeasts are two important volatile flavor substances in fermented alcoholic beverages (FABs). To improve the FABs overall quality, lab-scale huangjiu brewing and systematic evaluation were performed using 171 Saccharomyces cerevisiae strains. Finally, two S. cerevisiae strains that produced lower HAs and higher AEs were obtained and named jiangnan1# and jiangnan3#, respectively. The results of production-scale huangjiu fermentation indicated that HAs produced by jiangnan1# sample decreased by 24.99 %, and AEs produced by jiangnan1# increased by 36.35 %. Sensory evaluation showed that the acidic taste, honey aroma attribute intensity were higher in 85# huagnjiu, and the fruity aroma attribute intensity was higher in jiangnan1# huangjiu (P < 0.01). Moreover, urea and ethyl carbamate produced by jiangnan1# strain were degraded by 13.89 % and 45.51 % compared with those of the control strain 85#, indicating the positive effects of jiangnan1# strain on health and safety. Thus, the obtained S. cerevisiae strains in this study can better enhance the flavor and improve the drinking safety and comfort of huangjiu.


Assuntos
Álcoois , Saccharomyces cerevisiae , Acetatos/metabolismo , Álcoois/metabolismo , Ésteres/metabolismo , Saccharomyces cerevisiae/metabolismo , Ureia/metabolismo , Uretana/metabolismo
8.
Microbiologyopen ; 11(5): e1322, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36314758

RESUMO

Geobacter species have great application potential in remediation processes and electrobiotechnology. In all applications, understanding the metabolism will enable target-oriented optimization of the processes. The typical electron donor and carbon source of the Geobacter species is acetate, while fumarate is the usual electron acceptor. Here, we could show that depending on the donor/acceptor ratio in batch cultivation of Geobacter sulfurreducens different product patterns occur. With a donor/acceptor ratio of 1:2.5 malate accumulated as an intermediate product but was metabolized to succinate subsequently. At the end of the cultivation, the ratio of fumarate consumed and succinate produced was approximately 1:1. When fumarate was added in excess, malate accumulated in the fermentation broth without further metabolization. After the addition of acetate to stationary cells, malate concentration decreased immediately and additional succinate was synthesized. Finally, it was shown that also resting cells of G. sulfurreducens could efficiently convert fumarate to malate without an additional electron donor. Overall, it was demonstrated that by altering the donor/acceptor ratio, targeted optimization of the metabolite conversion by G. sulfurreducens can be realized.


Assuntos
Geobacter , Geobacter/metabolismo , Malatos/metabolismo , Transporte de Elétrons , Ácido Succínico/metabolismo , Fumaratos/metabolismo , Acetatos/metabolismo , Oxirredução
9.
J Microbiol ; 60(12): 1139-1152, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36279104

RESUMO

Acetyl-CoA synthetase (ACS) is the enzyme that irreversibly catalyzes the synthesis of acetyl-CoA from acetate, CoA-SH, and ATP via acetyl-AMP as an intermediate. In this study, we demonstrated that AcsA1 (MSMEG_6179) is the predominantly expressed ACS among four ACSs (MSMEG_6179, MSMEG_0718, MSMEG_3986, and MSMEG_5650) found in Mycobacterium smegmatis and that a deletion mutation of acsA1 in M. smegmatis led to its compromised growth on acetate as the sole carbon source. Expression of acsA1 was demonstrated to be induced during growth on acetate as the sole carbon source. The acsA1 gene was shown to be negatively regulated by Crp1 (MSMEG_6189) that is the major cAMP receptor protein (CRP) in M. smegmatis. Using DNase I footprinting analysis and site-directed mutagenesis, a CRP-binding site (GGTGA-N6-TCACA) was identified in the upstream regulatory region of acsA1, which is important for repression of acsA1 expression. We also demonstrated that inhibition of the respiratory electron transport chain by inactivation of the major terminal oxidase, aa3 cytochrome c oxidase, led to a decrease in acsA1 expression probably through the activation of CRP. In conclusion, AcsA1 is the major ACS in M. smegmatis and its gene is under the negative regulation of Crp1, which contributes to some extent to the induction of acsA1 expression under acetate conditions. The growth of M. smegmatis is severely impaired on acetate as the sole carbon source under respiration-inhibitory conditions.


Assuntos
Proteína Receptora de AMP Cíclico , Mycobacterium smegmatis , Mycobacterium smegmatis/genética , Proteína Receptora de AMP Cíclico/genética , Proteína Receptora de AMP Cíclico/metabolismo , Acetilcoenzima A/genética , Acetilcoenzima A/metabolismo , Regulação Bacteriana da Expressão Gênica , Proteínas de Bactérias/metabolismo , Acetatos/metabolismo , Carbono/metabolismo , Ligases/genética , Ligases/metabolismo
10.
Appl Microbiol Biotechnol ; 106(22): 7627-7642, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36264306

RESUMO

The study was conducted to evaluate the rumen microbiota as well as the milk composition and milk component yields of Holstein cows supplemented with fermented soybean meal (FSBM). Eighteen Holstein cows in their 2nd parity with 54.38 ± 11.12 SD days in milking (DIM) were divided into two dietary groups (CON and TRT) of nine cows per group. The cows in the TRT group received 300 g of FSBM per cow per day in addition to the conventional diet, while each cow in the CON group was supplemented with 350 g of soybean meal (SBM) in their diet daily throughout the 28-day feeding trial. Rumen bacterial composition was detected via 16S rRNA sequencing, and the functional profiles of bacterial communities were predicted. Milk composition, milk yield, as well as rumen fermentation parameters, and serum biochemistry were also recorded. The inclusion of FSBM into the diets of Holstein cows increased the milk urea nitrogen (MUN), milk protein yield, fat corrected milk (FCM), and milk fat yield while the milk somatic cell count (SCC) was decreased. In the rumen, the relative abundances of Fibrobacterota, and Spirochaetota phyla were increased in the TRT group, while the percentage of Proteobacteria was lower. In addition, the supplementation of FSBM to Holstein cows increased the acetate percentage, rumen pH, and acetate to propionate ratio, while the proportion of propionate and propionate % was observed to decrease in the TRT group. The KEGG pathway and functional prediction revealed an upregulation in the functional genes associated with the biosynthesis of amino acids in the TRT group. This enrichment in functional genes resulted in an improved synthesis of several essential amino acids including lysine, methionine, and branch chain amino acids (BCAA) which might be responsible for the increased milk protein yield. Future studies should employ shotgun metagenomics, transcriptomics, and metabolomics technology to investigate the effects of FSBM on other rumen microbiomes and milk protein synthesis in the mammary gland in Holstein cows. KEY POINTS: • The supplementation of fermented soybean meal (FSBM) to Holstein cows modified the proportion of rumen bacteria. • Predicted metabolic pathways and functional genes of rumen bacteria revealed an enrichment in pathway and genes associated with biosynthesis of amino acids in the group fed FSBM. • The cows supplemented with FSBM record an improved rumen fermentation. • Cows supplemented with FSBM recorded an increased yield of milk protein and milk fat.


Assuntos
Alimentos Fermentados , Microbiota , Animais , Bovinos , Feminino , Gravidez , Acetatos/metabolismo , Ração Animal , Dieta/veterinária , Suplementos Nutricionais , Fermentação , Lactação , Metionina/metabolismo , Proteínas do Leite/metabolismo , Proteínas do Leite/farmacologia , Propionatos/metabolismo , RNA Ribossômico 16S/metabolismo , Rúmen/microbiologia , Soja/metabolismo
11.
Int J Food Microbiol ; 383: 109938, 2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36202011

RESUMO

Fungal spoilage limits the shelf life of fermented dairy products. To address the problem, this study explores the potential of lactic acid bacteria as antifungal adjunct cultures in dairy matrices. Strains of lactic acid bacteria (113) representing 19 species were screened for their activity against Penicillium caseifulvum, Aspergillus clavatus and Mucor racemosus in modified MRS medium, milk, and yogurt. Strains of Lactiplantibacillus plantarum, Furfurilactobacillus milii, and Lentilactobacillus parabuchneri inhibited the growth of mycelial fungi. The inhibitory effects of lactic acid bacteria against yeasts were also determined in yogurt with Candida sake, Saccharomyces bayanus, and Torulaspora delbrueckii as challenge strains. The inhibition of yeasts by lactic acid bacteria was strain-specific and unrelated to the activity towards mycelial fungi. Organic acids and hydroxy fatty acids were quantified by liquid chromatograph coupled with refractive index detector and tandem mass spectrometry, respectively. Principal component analysis indicated 10-OH 18: 1 fatty acids and acetate are the main antifungal metabolites and explained over 50 % of the antifungal activity. The correlation analysis of metabolites and mold-free shelf life of milk and yogurt confirmed the role of these compounds. The genomic study analysed genes related to the production of major antifungal metabolites and predicted the formation of 1,2-propanediol and acetate but not of hydroxy unsaturated fatty acids. The findings provide new perspectives on the selection of antifungal strains, the characterization of antifungal metabolites and the exploration of antifungal mechanisms among different species.


Assuntos
Lactobacillales , Lactobacillales/metabolismo , Antifúngicos/farmacologia , Fermentação , Propilenoglicol/metabolismo , Lactobacillaceae/metabolismo , Leveduras/metabolismo , Acetatos/metabolismo , Ácidos Graxos/metabolismo
12.
Metab Eng ; 74: 98-107, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36244545

RESUMO

Rising concerns about climate change and sustainable energy have attracted efforts towards developing environmentally friendly alternatives to fossil fuels. Biosynthesis of n-butane, a highly desirable petro-chemical, fuel additive and diluent in the oil industry, remains a challenge. In this work, we first engineered enzymes Tes, Car and AD in the termination module to improve the selectivity of n-butane biosynthesis, and ancestral reconstruction and a synthetic RBS significantly improved the AD abundance. Next, we did ribosome binding site (RBS) calculation to identify potential metabolic bottlenecks, and then mitigated the bottleneck with RBS engineering and precursor propionyl-CoA addition. Furthermore, we employed a model-assisted strain design and a nonrepetitive extra-long sgRNA arrays (ELSAs) and quorum sensing assisted CRISPRi to facilitate a dynamic two-stage fermentation. Through systems engineering, n-butane production was increased by 168-fold from 0.04 to 6.74 mg/L. Finally, the maximum n-butane production from acetate was predicted using parsimonious flux balance analysis (pFBA), and we achieved n-butane production from acetate produced by electrocatalytic CO reduction. Our findings pave the way for selectively producing n-butane from renewable carbon source.


Assuntos
Escherichia coli , Engenharia Metabólica , Escherichia coli/genética , Escherichia coli/metabolismo , Butanos/metabolismo , Acetatos/metabolismo
13.
J Agric Food Chem ; 70(37): 11520-11530, 2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36066388

RESUMO

The goal of this study was to evaluate how grape composition modifications linked to maturity level could affect the wine ester composition and aromatic expression. An experimental design has been developed from grapes of Vitis vinifera cv Merlot and cv Tempranillo. On each vine plot, grapes have been harvested at two maturity levels and have been fermented using a commercial yeast strain under standardized conditions, specifically after having the sugar and nitrogen concentrations adjusted to the same target values. Tempranillo wine ester content was not impacted by the maturity level, whereas Merlot wines from the highest maturity level showed lower concentrations for fatty acid ethyl esters and higher alcohol acetates but higher concentrations for substituted ethyl esters. Sensory analysis corroborated these analytical results: when Merlot maturity increased, wine fruity aromatic expression decreased (particularly its global intensity and the fresh, red-berry, and fermentative fruit characters). In addition, aromatic reconstitution experiments showed that esters were not, alone, responsible for the sensory differences linked to grapes' maturity. Globally, our results highlight the role of esters in the overall wine fruity aromatic expression associated to Merlot ripeness and show that their levels are impacted by other parameters than the grape content in sugars and amino acids, well known as being their precursors.


Assuntos
Vitis , Vinho , Acetatos/metabolismo , Aminoácidos/metabolismo , Ésteres/análise , Frutas/química , Nitrogênio/metabolismo , Saccharomyces cerevisiae , Açúcares/metabolismo , Vitis/química , Vinho/análise
14.
Sci Rep ; 12(1): 15932, 2022 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-36151241

RESUMO

Elevated levels of ruminal lipopolysaccharides (LPS) have been linked to ruminal acidosis; however, they result in reduced endotoxicity compared to LPS derived from species like Escherichia coli. Additionally, there is a knowledge gap on the potential effect of LPS derived from ruminal microbiome on ruminal bacteria species whose abundance is associated with ruminal acidosis. The objective of this study was to evaluate the effects of LPS-free anaerobic water (CTRL), E. coli-LPS (E. COLI), ruminal-LPS (RUM), and a 1:1 mixture of E. coli and ruminal-LPS (MIX) on the growth characteristics and fermentation end products of lactate-producing bacteria (Streptococcus bovis JB1, Selenomonas ruminantium HD4) and lactate-utilizing bacterium (Megasphaera elsdenii T81). The growth characteristics were predicted based on the logistic growth model, the ammonia concentration was determined by the phenolic acid/hypochlorite method and organic acids were analyzed with high performance liquid chromatography. Results indicate that, compared to the CTRL, the maximum specific growth rate of S. bovis JB1 decreased by approximately 19% and 23% when RUM and MIX were dosed, respectively. In addition, acetate and lactate concentrations in Se. ruminantium HD4 were reduced by approximately 30% and 18%; respectively, in response to MIX dosing. Compared to CTRL, lactate concentration from S. bovis JB1 was reduced approximately by 31% and 22% in response to RUM and MIX dosing; respectively. In summary, RUM decreased the growth and lactate production of some lactate-producing bacteria, potentially mitigating the development of subacute ruminal acidosis by restricting lactate availability to some lactate-utilizing bacteria that metabolize lactate into VFAs thus further contributing to the development of acidosis. Also, RUM did not affect Megasphaera elsdenii T81 growth.


Assuntos
Acidose , Rúmen , Acetatos/metabolismo , Acidose/metabolismo , Amônia/metabolismo , Animais , Bactérias/metabolismo , Escherichia coli/metabolismo , Fermentação , Concentração de Íons de Hidrogênio , Ácido Hipocloroso/metabolismo , Ácido Láctico/metabolismo , Lipopolissacarídeos/metabolismo , Rúmen/microbiologia , Água/metabolismo
15.
Biomolecules ; 12(9)2022 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-36139028

RESUMO

The cerebellum, or "little brain", is often overlooked in studies of brain metabolism in favour of the cortex. Despite this, anomalies in cerebellar amino acid homeostasis in a range of disorders have been reported. Amino acid homeostasis is central to metabolism, providing recycling of carbon backbones and ammonia between cell types. Here, we examined the role of cerebellar amino acid transporters in the cycling of glutamine and alanine in guinea pig cerebellar slices by inhibiting amino acid transporters and examining the resultant metabolism of [1-13C]d-glucose and [1,2-13C]acetate by NMR spectroscopy and LCMS. While the lack of specific inhibitors of each transporter makes interpretation difficult, by viewing results from experiments with multiple inhibitors we can draw inferences about the major cell types and transporters involved. In cerebellum, glutamine and alanine transfer is dominated by system A, blockade of which has maximum effect on metabolism, with contributions from System N. Inhibition of neural system A isoform SNAT1 by MeAIB resulted in greatly decreased metabolite pools and reduced net fluxes but showed little effect on fluxes from [1,2-13C]acetate unlike inhibition of SNAT3 and other glutamine transporters by histidine where net fluxes from [1,2-13C]acetate are reduced by ~50%. We interpret the data as further evidence of not one but several glutamate/glutamine exchange pools. The impact of amino acid transport inhibition demonstrates that the cerebellum has tightly coupled cells and that glutamate/glutamine, as well as alanine cycling, play a major role in that part of the brain.


Assuntos
Amônia , Glutamina , Acetatos/metabolismo , Alanina/metabolismo , Alanina/farmacologia , Amônia/metabolismo , Animais , Carbono/metabolismo , Cerebelo/metabolismo , Glucose/metabolismo , Glutamatos/metabolismo , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Cobaias , Histidina/metabolismo
16.
Biomolecules ; 12(9)2022 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-36139076

RESUMO

Bilirubin (BR) is a tetrapyrrolic compound stemming from heme catabolism with diverse physiological functions. It can be oxidized by H2O2 to form several degradation products, some of which have been detected in vivo and may contribute to the pathogenesis of certain diseases. However, the oxidative degradation of BR is complex and the conditions that BR degradation occurs pathophysiologically remain obscure. Neutrophils are known to generate large amounts of reactive oxygen species, including H2O2, upon activation and they are mobilized to inflammatory sites; therefore, we hypothesized that activated neutrophils could cause BR degradation, which could occur at inflammatory sites. In the present study, we investigated BR degradation by H2O2 and identified hematinic acid (BHP1) and a new product BHP2, whose structure was characterized as 2,5-diformyl-4-methyl-1H-pyrrole-3-propanoic acid. An LC-MS/MS method for the quantitation of the two compounds was then established. Using the LC-MS/MS method, we observed the concentration-dependent formation of BHP1 and BHP2 in mouse neutrophils incubated with 10 and 30 µM of BR with the yields being 16 ± 3.2 and 31 ± 5.9 pmol/106 cells for BHP1, and 25 ± 4.4 and 71 ± 26 pmol/106 cells for BHP2, respectively. After adding phorbol 12-myristate 13-acetate, a neutrophil agonist, to 30 µM of BR-treated cells, the BHP1 yield increased to 43 ± 6.6 pmol/106 cells, whereas the BHP2 one decreased to 47 ± 9.2 pmol/106 cells. The two products were also detected in hemorrhagic skins of mice with dermal inflammation and hemorrhage at levels of 4.5 ± 1.9 and 0.18 ± 0.10 nmol/g tissue, respectively, which were significantly higher than those in the non-hemorrhagic skins. BHP2 was neurotoxic starting at 0.10 µM but BHP1 was not, as assessed using Caenorhabditis elegans as the animal model. Neutrophil-mediated BR degradation may be a universally pathophysiological process in inflammation and can be particularly important under pathological conditions concerning hemorrhage.


Assuntos
Neutrófilos , Propionatos , Acetatos/metabolismo , Animais , Bilirrubina , Cromatografia Líquida , Heme/metabolismo , Peróxido de Hidrogênio/metabolismo , Inflamação/metabolismo , Camundongos , Miristatos/metabolismo , Neutrófilos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Espectrometria de Massas em Tandem , Acetato de Tetradecanoilforbol/farmacologia
17.
Molecules ; 27(18)2022 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-36144867

RESUMO

Distiller's grain is rich in natural active ingredients and can be used as an excellent antioxidant feed for goats. The current study aimed to assess the feeding value of four different types of distiller's grains with an in vitro gas production trial. The chemical composition, total phenols, total anthocyanins, dry matter degradability, methane, hydrogen, and rumen fermentation parameters were evaluated. The results indicated that red distiller's grain and glutinous rice distiller's grain had higher (p < 0.05) levels of crude protein than the other two types. There were significantly (p < 0.05) higher concentrations of dry matter, ether extract, hemicellulose, and total carbohydrate in corn distiller's grain than in the other three types of distiller's grain. In addition, red distiller's grain showed a higher (p < 0.05) gas production rate constant (c) and ruminal outflow rate, as well as higher (p < 0.05) concentrations of total phenol, total anthocyanins and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, than the other three types of distiller's grains. In contrast, red distiller's grain displayed the lowest (p < 0.05) immediately soluble fraction (a) and half the time of maximum gas production relative to the other samples. In particular, the levels of methane (%) in white distiller's grain and glutinous rice distiller's grain were greater (p < 0.05) than that in red distiller's grain. Moreover, the ammonia nitrogen content in red distiller's grain was greater (p < 0.05) than that in white distiller's grain and corn distiller's grain. In contrast, red distiller's grain exhibited a lower (p < 0.05) level of ruminal fluid acetic acid relative to that found in white distiller's grain and corn distiller's grain. Taken together, the results showed that red distiller's grain and glutinous rice distiller's grain could be used as protein feed, red distiller's grain had higher levels of total phenols and total anthocyanins and a high DPPH scavenging activity; corn distiller's grain might be considered as an alternative energy source feed, and white distiller's grain exhibited higher total gas production.


Assuntos
Ração Animal , Rúmen , Acetatos/metabolismo , Amônia , Ração Animal/análise , Animais , Antocianinas/metabolismo , Antioxidantes/metabolismo , Dieta/veterinária , Grão Comestível/metabolismo , Éteres , Fermentação , Hidrogênio/metabolismo , Metano/metabolismo , Nitrogênio/metabolismo , Fenol/metabolismo , Extratos Vegetais/metabolismo , Rúmen/metabolismo , Zea mays/metabolismo
18.
Bioprocess Biosyst Eng ; 45(11): 1857-1864, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36153378

RESUMO

To simulate acetate consumption and electricity generation in a cycle of a microbial fuel cell (MFC) treating synthetic acetate-based wastewater with low concentration, nonelectrogenic bacteria (NEB), which had no contribution in electricity generation, was incorporated with methanogen's kinetic parameters into a previous biofilm model proposed by Marcus et al. (Biotechnol Bioeng 98:1171-1182, 2007). However, the Coulombic efficiency was estimated to be 40.1%, whereas the experiment showed 13.6%, as the presence of NEB was obviously underestimated. Thus, the maximum NEB reaction rate (qmaxC) was temporarily calibrated, and a sensitivity analysis was then conducted. As a result, the growth parameters of NEB, the growth of the exoelectrogenic bacteria, and the biofilm detachment were identified as influential parameters. qmaxC and a half rate constant of NEB (KsC) were selected as potential calibration parameters. The two sets of calibrated parameters (0.342 mmol-acetate (Ac)/mg-volatile solids (VS)/d of qmaxC and 33.8 mg-carbon (C)/L of KsC; 0.274 mmol-Ac/mg-VS/d of qmaxC and 16.9 mg-C/L of KsC) showed a good agreement with the experimental results at 100 mg-C/L of initial acetate. However, the calibrated parameter values obviously differed from those in previous models. The calibrated model also showed good agreement with the experimental results at 50 and 200 mg-C/L of the initial acetate. In view of the different values of qmaxC and KsC from those of methanogenic bacteria in previous models and the previous findings on anode microbial community, which showed that NEB are not only methanogenic bacteria, we concluded that the diversity of NEB should be considered to simulate performances in a cycle of MFC treating low organic matter concentrations.


Assuntos
Fontes de Energia Bioelétrica , Fontes de Energia Bioelétrica/microbiologia , Eletricidade , Bactérias/metabolismo , Eletrodos , Acetatos/metabolismo
19.
J Biotechnol ; 359: 29-34, 2022 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-36150604

RESUMO

Isopropanol has a good potential as a new fuel substitution. In the model biosynthesis pathway of isopropanol synthesis, acetoacetyl-CoA is converted to acetoacetate by acetoacetyl-CoA transferases, which requires an acetate molecule as a substrate. Herein, a novel isopropanol synthesis pathway based on mammalian ketone metabolic pathway was developed. In this pathway, acetoacetyl-CoA is condensed with acetyl-CoA to generate 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) by HMG-CoA synthase, and then catalyzed by HMG-CoA lyase to generate acetoacetate. This process is acetate-independent. Under the same experimental system using glycerol as carbon source, the E. coli strain MG::ISOP1 containing the novel pathway produced 11.7 times more isopropanol than the strain MG::ISOP0 containing the model pathway. The pta-ackA knockout mutant strain MG∆pta-ackA::ISOP1, which reduced the conversion of acetyl-CoA to acetate, further increased the production from 76 mg/L to 360 mg/L. In another strategy, knocking out atoDA to block the acetoacetate degradation pathway in strain MG∆atoDA::ISOP1 increased the production to 680 mg/L. By knocking out both of pta-ackA and atoDA, strain MGΔpta-ackAΔatoDA::ISOP1 produced 964 mg/L of isopropanol, which was 12.7 times that of MG::ISOP1. This study indicated that the novel pathway is competent for isopropanol synthesis, and provides a new perspective for biosynthesis of isopropanol.


Assuntos
2-Propanol , Escherichia coli , Escherichia coli/genética , Escherichia coli/metabolismo , 2-Propanol/metabolismo , Acetoacetatos/metabolismo , Acetilcoenzima A/metabolismo , Coenzima A-Transferases/metabolismo , Hidroximetilglutaril-CoA Sintase/genética , Hidroximetilglutaril-CoA Sintase/metabolismo , Glicerol/metabolismo , Acetatos/metabolismo , Carbono/metabolismo
20.
Int J Mol Sci ; 23(18)2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-36142400

RESUMO

This study explores the effects of the coevolution of the host genome (the first genome) and gut microbiome (the second genome) on nutrition stress in Tibetan sheep during the cold season. The rumen epithelial tissue of six Tibetan sheep (Oula-type) was collected as experimental samples during the cold and warm seasons and the study lasted for half a year. The cDNA library was constructed and subjected to high-throughput sequencing. The circRNAs with significant differential expression were identified through bioinformatics analysis and functional prediction, and verified by real-time quantitative PCR (qRT-PCR). The results showed that a total of 56 differentially expressed (DE) circRNAs of rumen epithelial tissue were identified using RNA-seq technology, among which 29 were significantly upregulated in the cold season. The circRNA-miRNA regulatory network showed that DE circRNAs promoted the adaptation of Tibetan sheep in the cold season by targeting miR-150 and oar-miR-370-3p. The results of correlation analysis among circRNAs, microbiota, and metabolites showed that the circRNA NC_040275.1:28680890|28683112 had a very significant positive correlation with acetate, propionate, butyrate, and total volatile fatty acid (VFA) (p < 0.01), and had a significant positive correlation with Ruminococcus-1 (p < 0.05). In addition, circRNA NC_040256.1:78451819|78454934 and metabolites were enriched in the same KEGG pathway biosynthesis of amino acids (ko01230). In conclusion, the host genome and rumen microbiome of Tibetan sheep co-encoded a certain glycoside hydrolase (ß-glucosidase) and coevolved efficient VFA transport functions and amino acid anabolic processes; thus, helping Tibetan sheep adapt to nutrient stress in the cold season in high-altitude areas.


Assuntos
Celulases , MicroRNAs , Microbiota , Acetatos/metabolismo , Aminoácidos/metabolismo , Animais , Butiratos/metabolismo , Celulases/metabolismo , Ácidos Graxos Voláteis/metabolismo , Glicosídeo Hidrolases/metabolismo , MicroRNAs/genética , Propionatos/análise , RNA Circular/genética , Rúmen/química , Estações do Ano , Ovinos/genética , Tibet
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