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1.
PLoS One ; 15(4): e0232278, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32352997

RESUMO

Peanut (Arachis hypogaea) is mainly grown for oil extraction and the remaining oil-free seed referred as peanut meal (PM) leaves with high protein content which can be a possible substitute for fishmeal in aqua-diets. This study evaluates the suitability of three types of processed peanut seeds, namely untreated PM (UPM), fermented PM (FPM), and germinated PM (GPM) from peanut seeds to replace fishmeal in barramundi (Lates calcarifer) diets cultured under a commercial production environment. Nine formulated diets having 3 inclusion levels from the 3 different peanuts (15%, 30% and 60% fishmeal replacement) were evaluated against a control without PM. The performance of various types and levels of PMs was assessed by examining the growth, gut and liver condition and survival of fish after eight weeks of feeding the test diets. The immunological responses of juvenile barramundi were assessed by exposing the fish to the hypoxic conditions for 4 hours. The results showed that fermentation and germination significantly (P<0.05) reduced the tannins and alkaloid contents in the PMs. The fish fed 15% GPM diet grew faster and had higher survival than fish fed control diet, while fish fed diet including 60% GPM showed a significant reduction in growth and survival, and an increase in food conversion rate (FCR). FPM and UPM at any inclusion levels did not alter the growth, survival and FCR. Histology analysis revealed that fish fed 60% GPM and UPM showed higher amount of lipid droplets in liver, myodigeneration in fish muscle and a decrease number of acidic mucins in distal gut compare to all other test diets. Stress caused by reduced dissolved oxygen did not change the sodium, potassium, chlorides and alanine aminotransferase concentrations of plasma of fish fed any diet. However, the stress did increase plasma cortisol significantly (P<0.05) in fish fed 60% GPM, 30% and 60% UPM diets. These results suggest that the PMs can partly replace the fishmeal in juvenile barramundi diet and the processing further improves the PMs quality by reducing its antinutritional factors which in turn can increase either its inclusion level in the barramundi diets or improved growth and health status of the species.


Assuntos
Arachis/metabolismo , Fermentação/fisiologia , Germinação/fisiologia , Hipóxia/metabolismo , Perciformes/crescimento & desenvolvimento , Sementes/metabolismo , Ração Animal , Animais , Aquicultura/métodos , Dieta , Fígado/metabolismo , Refeições
2.
Nat Commun ; 11(1): 1783, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32286292

RESUMO

The microbial adaptations to the respiratory burst remain poorly understood, and establishing how the NADPH oxidase (NOX2) kills microbes has proven elusive. Here we demonstrate that NOX2 collapses the ΔpH of intracellular Salmonella Typhimurium. The depolarization experienced by Salmonella undergoing oxidative stress impairs folding of periplasmic proteins. Depolarization in respiring Salmonella mediates intense bactericidal activity of reactive oxygen species (ROS). Salmonella adapts to the challenges oxidative stress imposes on membrane bioenergetics by shifting redox balance to glycolysis and fermentation, thereby diminishing electron flow through the membrane, meeting energetic requirements and anaplerotically generating tricarboxylic acid intermediates. By diverting electrons away from the respiratory chain, glycolysis also enables thiol/disulfide exchange-mediated folding of bacterial cell envelope proteins during periods of oxidative stress. Thus, primordial metabolic pathways, already present in bacteria before aerobic respiration evolved, offer a solution to the stress ROS exert on molecular targets at the bacterial cell envelope.


Assuntos
Glicólise/fisiologia , NADPH Oxidases/metabolismo , Estresse Oxidativo/fisiologia , Salmonella typhimurium/enzimologia , Salmonella typhimurium/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Fermentação/genética , Fermentação/fisiologia , Glicólise/genética , NADPH Oxidases/genética , Oxirredução , Estresse Oxidativo/genética , Espécies Reativas de Oxigênio/metabolismo , Salmonella typhimurium/genética
3.
PLoS One ; 15(3): e0229556, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32196504

RESUMO

The heterotrophic microalgae Crypthecodinium cohnii was usually cultivated in complex medium containing glucose, yeast extract and sea salt. For the preparation of DHA with highest purity, a new defined medium without the yeast extract was developed. Different inoculated densities, C/N ratios, temperatures, culture volumes and glucose additions were investigated to optimize the algal growth rate and DHA production. The growth period in C. cohnii was shortened from 12-14 days to 7-8 days, the OD600 was enhanced from 2.0 to 3.0, the glucose consumption was accelerated and used up on day 3-4, and the DHA content in culture were increased from 10 to 45 nmoles/300 µl batch. It was found that C. cohnii had optimal growth and DHA accumulation in 25 °C, 0.2 inoculated density, 5-10 C/N ratio, 5:1 air/culture volume ratio. This is the first time DHA production using C.cohnii has been optimized in synthetic medium. This allows preparation of uniformly radiolabeled 13C- and 14C-DHA.


Assuntos
Meios de Cultura/química , Dinoflagelados/crescimento & desenvolvimento , Ácidos Docosa-Hexaenoicos/biossíntese , Biomassa , Dinoflagelados/metabolismo , Fermentação/fisiologia , Microalgas/crescimento & desenvolvimento
4.
Infect Immun ; 88(2)2020 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-31685547

RESUMO

The fungus Mucor circinelloides undergoes yeast-mold dimorphism, a developmental process associated with its capability as a human opportunistic pathogen. Dimorphism is strongly influenced by carbon metabolism, and hence the type of metabolism likely affects fungus virulence. We investigated the role of ethanol metabolism in M. circinelloides virulence. A mutant in the adh1 gene (M5 strain) exhibited higher virulence than the wild-type (R7B) and the complemented (M5/pEUKA-adh1 +) strains, which were nonvirulent when tested in a mouse infection model. Cell-free culture supernatant (SS) from the M5 mutant showed increased toxic effect on nematodes compared to that from R7B and M5/pEUKA-adh1 + strains. The concentration of acetaldehyde excreted by strain M5 in the SS was higher than that from R7B, which correlated with the acute toxic effect on nematodes. Remarkably, strain M5 showed higher resistance to H2O2, resistance to phagocytosis, and invasiveness in mouse tissues and induced an enhanced systemic inflammatory response compared with R7B. The mice infected with strain M5 under disulfiram treatment exhibited only half the life expectancy of those infected with M5 alone, suggesting that acetaldehyde produced by M. circinelloides contributes to the toxic effect in mice. These results demonstrate that the failure in fermentative metabolism, in the step of the production of ethanol in M. circinelloides, contributes to its virulence, inducing a more severe tissue burden and inflammatory response in mice as a consequence of acetaldehyde overproduction.


Assuntos
Fermentação/fisiologia , Mucor/metabolismo , Mucor/patogenicidade , Virulência/fisiologia , Álcool Desidrogenase/metabolismo , Animais , Linhagem Celular , Fermentação/efeitos dos fármacos , Proteínas Fúngicas/metabolismo , Peróxido de Hidrogênio/farmacologia , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mucor/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Fagocitose/fisiologia , Células RAW 264.7 , Virulência/efeitos dos fármacos
5.
Int J Food Microbiol ; 317: 108463, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-31809966

RESUMO

Paocai is a widely consumed Chinese traditional fermented vegetable product. To understand the effect of temperature on paocai fermentation flora, the bacterial community structure of paocai fermented at 10 °C, 15 °C, 25 °C and 35 °C was analyzed by culture-dependent and culture-independent methods. The results showed that increasing the fermentation temperature in a certain range is beneficial for rapid paocai acid production and shortening of the maturity period. Illumina Miseq sequencing was performed on 56 samples at different fermentation process temperatures using a culture-independent method. A total of 1,964,231 high-quality reads of 16S rRNA V3-V4 regions were obtained, and they were divided into 405 operational taxonomic units (OTUs) and identified as 213 bacterial genera. The bacterial diversity decreased with the progression of fermentation, and some spoiled samples had an increased diversity. The culture-independent method found that at 10 °C, Lactococcus appeared at the start of fermentation, Leuconostoc and Weissella appeared in the middle of fermentation, and Lactobacillus and Leuconostoc dominated fermentation in the late stage. At 15 °C, Lactococcus started fermentation, Leuconostoc appeared in the middle stage, and Lactobacillus was dominant in the late stage. At 25 °C, Lactococcus started fermentation, Weissella and Lactobacillus appeared in the middle stage, and Lactobacillus dominated fermentation in the late stage. Finally, at 35 °C, Lactococcus, Weissella, and Lactobacillus started fermentation, Weissella and Lactobacillus appeared in the middle stage, and Lactobacillus dominated fermentation in the late stage. A total of 647 strains of bacteria were isolated by culture-dependent methods and were divided into 12 genera and 19 species by randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) and 16S ribosomal RNA gene (rDNA) sequencing technology. More types of bacteria were isolated in the early stage of fermentation. At 10 °C, Lactococcus lactis began fermentation, and Lactobacillus brevis and Leuconostoc mesenteroides dominated acid production in the middle and late stages of paocai fermentation. At 15 °C, L. lactis initiates fermentation, while Lactobacillus plantarum dominates the acid fermentation of paocai. At 25 °C and 35 °C, there were a large number of Enterobacteriaceae bacteria in the start-up fermentation stage, and L. plantarum was dominant after 1-2 days of fermentation. Redundancy analysis (RDA) found that the lower the temperature, the more bacterial species that are produced, and the higher the temperature and the longer the time, the more obvious are the effects of L. plantarum on paocai. The results of dominant bacteria studied by culture-dependent and culture-independent methods are similar. The results indicate that most of the dominant microorganisms in the paocai fermentation system are culturable. This discovery can provide data and physical support for modernization and regulation of different types of paocai production.


Assuntos
Fermentação/fisiologia , Alimentos e Bebidas Fermentados/microbiologia , Lactobacillus plantarum/metabolismo , Lactococcus/metabolismo , Leuconostoc/metabolismo , Weissella/metabolismo , Temperatura Baixa , Técnicas de Cultura , DNA Bacteriano/genética , DNA Ribossômico/genética , Microbiologia de Alimentos/métodos , Temperatura Alta , Lactobacillus plantarum/genética , Lactococcus/genética , Leuconostoc/genética , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Weissella/genética
6.
Int J Food Microbiol ; 317: 108462, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-31794930

RESUMO

Yeasts involved in the spontaneous fermentation of traditional beverages like chicha (indigenous Andean beer) may have the potential to be used as starter cultures to improve the quality and microbiological safety of these products, but also as non-conventional alternatives to other food alcoholic fermentations. In this research, we isolated, identified and characterised yeast strains from four Ecuadorian chichas made by using four different raw materials: rice (RC), oat (OC), grape (GC) and a mixture of seven corn varieties (yamor, YC). Finally, 254 yeast isolates were obtained and identified by molecular methods. Eleven yeast genera and 16 yeast species were identified with relatively few isolates belonging to Saccharomyces cerevisiae (9.1% belonging to 6 strains) and Torulaspora delbrueckii (18.6% belonging to 2 strains). In order to select good candidates for fermentative starter production, different analyses were performed. The results of the stress response tests showed a wide variability between species and strains, and identified some yeasts displaying high stress tolerance, similarly to commercial wine strains. Amylase production was screened as being indicative of the capacity to degrade and ferment starch-rich substrates. A Cryptococcus sp. isolate showed the highest amylase activity. The growth rate and fermentative capacity in molasses medium was measured for three S. cerevisiae, T. delbrueckii and Candida sp. strains as tests for yield and performance in biomass production. Based on their excellent behaviour, three S. cerevisiae strains and one T. delbrueckii strain were selected for further analyses, including dehydration tolerance and invertase activity as additional desired traits for chicha starters. All the S. cerevisiae strains exhibited high invertase activity and one also displayed high resistance to dehydration. The yeasts selected in this study can thus be suitably used as dry starters for the microbiologically controlled production of traditional beverages, and also for other alcoholic fermentations.


Assuntos
Cerveja/microbiologia , Fermentação/fisiologia , Saccharomyces cerevisiae/metabolismo , Torulaspora/metabolismo , beta-Frutofuranosidase/metabolismo , Avena/microbiologia , Equador , Indústria Alimentícia , Oryza/microbiologia , Saccharomyces cerevisiae/isolamento & purificação , Torulaspora/isolamento & purificação , Vitis/microbiologia , Vinho/microbiologia , Leveduras/classificação , Leveduras/isolamento & purificação , Leveduras/metabolismo , Zea mays/microbiologia
7.
Int J Food Microbiol ; 312: 108362, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31669764

RESUMO

Stuck and sluggish fermentations are among the main problems in winemaking industry leading to important economic losses. Several factors have been described as causes of stuck and sluggish fermentations, being exposure to extreme temperatures barely studied. The objective of this study was to identify thermal conditions leading to stuck and sluggish fermentations, focusing on the impact of an abrupt and transient decrease/increase of temperature on fermentation performance and yeast viability/vitality. Different strains of Saccharomyces cerevisiae, SBB11, T73, and PDM were evaluated in synthetic grape must fermentations. Cold shocks (9 °C and 1.5 °C for 16 h) carried out on different days during the fermentation process were unable to alter fermentation performance. Conversely, shock temperatures higher than 32 °C, applied in early stages of the process, lead to sluggish fermentation showing a delay directly related to the temperature increase. Fermentation delay was associated with a decrease in cell vitality. The impact of the heat shock on fermentation performance was different depending on the strain evaluated and nitrogen supplementation (with or without diammonium phosphate addition). None of the conditions evaluated produced a stuck fermentation and importantly, in all cases must nutrition improved fermentation performance after a heat shock.


Assuntos
Temperatura Baixa , Fermentação/fisiologia , Temperatura Alta , Saccharomyces cerevisiae/metabolismo , Resposta ao Choque Frio/fisiologia , Resposta ao Choque Térmico/fisiologia , Fosfatos/farmacologia , Vitis/metabolismo , Vinho/análise
8.
J Food Sci ; 84(12): 3726-3734, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31834968

RESUMO

Ten probiotic cultures were screened for the ability to hydrolyze soy proteins and bile salt deconjugation (BSD) to select one lactobacilli and one bifidobacteria strain to produce fermented soy beverages (FSBs) containing acerola byproduct (ABP). Next, the effect of the strains and the ABP on the technological and sensory characteristics of these beverages was evaluated during refrigerated storage for up to 28 days. None of the tested strains presented any proteolytic activity against soy proteins. Among the probiotic strains, the best BSD activities were observed for Lactobacillus acidophilus LA-5 and Bifidobacterium longum BB-46, which were further employed, individually or combined, to produce FSB supplemented or not with ABP, using Streptococcus thermophilus TH-4 as a starter, and the effect of these strains and ABP on the technological and sensory acceptability of FSB was evaluated. The probiotic strains did not influence FBS texture parameters, but ABP increased firmness in the ready product. BB-46 increased acidity, therefore decreasing acceptance, whereas the presence of LA-5 and/or ABP increased acceptance, even though the appearance was negatively affected by ABP after 21 days of storage. Thus, the presence of LA-5 and ABP contributed for the sensory acceptance of the FSBs without affecting their technological features. PRACTICAL APPLICATION: Lactobacillus acidophilus LA-5, Bifidobacterium longum BB-46, and/or acerola byproduct (ABP) were applied in the production of fermented soy beverages (FSBs). Principal components analysis was used to evaluate the formulations of the 23 factorial design and the sensory attributes and the effect of storage independently and covariance was the matrix type used for mapping purposes. LA-5 and ABP contributed for the sensory acceptance of FSB, without affecting their technological features, and could be used by food processing companies after scaling up, also reducing the environmental impact by decreasing discarding byproducts, which are sources of bioactive compounds.


Assuntos
Alimentos e Bebidas Fermentados , Lactobacillus/metabolismo , Malpighiaceae/química , Probióticos/metabolismo , Alimentos de Soja , Fermentação/fisiologia , Alimentos e Bebidas Fermentados/análise , Alimentos e Bebidas Fermentados/microbiologia , Manipulação de Alimentos , Alimentos de Soja/análise , Alimentos de Soja/microbiologia
9.
PLoS One ; 14(12): e0214778, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31877130

RESUMO

Mathematical models that describe gas production are widely used to estimate the rumen degradation digestibility and kinetics. The present study presents a method to generate models by combining existing models and to propose the von Bertalanffy-Gompertz two-compartment model based on this method. The proposed model was compared with the logistic two-compartment one to indicate which best describes the kinetic curve of gas production through the semi-automated in vitro technique from different pinto peanut cultivars. The data came from an experiment grown and harvested at the Far South Animal Sciences station (Essul) in Itabela, BA, Brazil and gas production was read at 2, 4, 6, 8, 10, 12, 14, 17, 20, 24, 28, 32, 48, 72, and 96 h after the start of the in vitro fermentation process. The parameters were estimated by the least squares method using the iterative Gauss-Newton process in the software R version 3.4.1. The best model to describe gas accumulation was based on the adjusted coefficient of determination, residual mean squares, mean absolute deviation, Akaike information criterion, and Bayesian information criterion. The von Bertalanffy-Gompertz two-compartment model had the best fit to describe the cumulative gas production over time according to the methodology and conditions of the present study.


Assuntos
Arachis/crescimento & desenvolvimento , Arachis/metabolismo , Fermentação/fisiologia , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Animais , Teorema de Bayes , Brasil , Cinética , Modelos Biológicos , Modelos Teóricos , Rúmen/metabolismo
10.
Molecules ; 24(21)2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31694205

RESUMO

Leuconostoc lactis CCK940, which exhibits glycosyltransferase activity, produces oligosaccharides using sucrose and maltose as donor and receptor molecules, respectively. The oligosaccharides produced were purified by Bio-gel P2 chromatography and the purified oligosaccharides (CCK-oligosaccharides) consisted of only glucose. 1H-NMR analysis revealed that the CCK-oligosaccharides were composed of 77.6% α-1,6 and 22.4% α-1,4 glycosidic linkages, and the molecular weight of the CCK-oligosaccharides was found to be 9.42 × 102 Da. To determine the prebiotic effect of the CCK-oligosaccharides, various carbon sources were added in modified media. Growth of six probiotic strains, Lactobacillus casei, L. pentosus, L. plantarum, Weissella cibaria, Bifidobacterim animalis, and Saccharomyces cerevisiae, was better when the CCK-oligosaccharides were used as the sole carbon source compared to fructo-oligosaccharides, which are widely used as prebiotics. These results showed that the CCK-oligosaccharides produced from Leu. lactis CCK940 could serve as good candidates for novel prebiotics.


Assuntos
Leuconostoc/metabolismo , Oligossacarídeos/química , Bifidobacterium/metabolismo , Fermentação/fisiologia , Lactobacillus/metabolismo , Maltose/química , Prebióticos , Probióticos/química , Sacarose/química
11.
Pak J Pharm Sci ; 32(4(Supplementary)): 1913-1918, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31680092

RESUMO

Emerging resistance to existing antimicrobial agents is one of the growing concerns and a serious problem for public health globally. Currently available antimicrobial agents are potent and effective but surfacing resistance to these drugs has not been ruled out so far. Therefore, it is utmost important to explore new bioactive compounds from natural sources to meet future needs. The present study was designed to produce, optimize, characterize and evaluate antimicrobial, fibrinolytic and anti-coagulant potential of a new alkaline protease. Proteolytic strain from desert soils of Tharparkar, Pakistan was subjected to 16S rDNA sequencing and identified as Bacillus tequilensis ZMS-2(Genbank Accession No. MK101013). During submerged fermentation at 37ºC, maximum enzyme production (454 U/ml) was observed with 24h old inoculum. The best incubation time was 72h (544 U/ml), optimum inoculum size and pH was 10% at pH 8 with 494 and 506 U/ml, respectively. The best carbon source was starch (571 U/ml), while ideal substrate was wheat bran (536 U/ml). Optimal temperature and pH for proteolytic activity was 60ºC (420 U/ml) and 8 (332 U/ml). Alkaline protease showed antibacterial activity against Staphylococcus aureus (27mm), Bacillus licheniformis (20mm), Klebsiella pneumoniae (17mm) and Escherichia coli (15mm). The strain B. tequilensis ZMS-2 also exhibited anticoagulant, fibrinolytic and dehairing potential suggesting application of its protease in various industries.


Assuntos
Anti-Infecciosos/farmacologia , Anticoagulantes/farmacologia , Bacillus/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/farmacologia , Endopeptidases/metabolismo , Endopeptidases/farmacologia , Fibrinolíticos/farmacologia , Meios de Cultura/metabolismo , Fermentação/fisiologia , Concentração de Íons de Hidrogênio , Paquistão , Temperatura
12.
Appl Microbiol Biotechnol ; 103(21-22): 8763-8784, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31641815

RESUMO

Microbial xylanases have gathered great attention due to their biotechnological potential at industrial scale for many processes. A variety of lignocellulosic materials, such as sugarcane bagasse, rice straw, rice bran, wheat straw, wheat bran, corn cob, and ragi bran, are used for xylanase production which also solved the great issue of solid waste management. Both solid-state and submerged fermentation have been used for xylanase production controlled by various physical and nutritional parameters. Majority of xylanases have optimum pH in the range of 4.0-9.0 with optimum temperature at 30-60 °C. For biochemical, molecular studies and also for successful application in industries, purification and characterization of xylanase have been carried out using various appropriate techniques. Cloning and genetic engineering are used for commercial-level production of xylanase, to meet specific economic viability and industrial needs. Microbial xylanases are used in various biotechnological applications like biofuel production, pulp and paper industry, baking and brewing industry, food and feed industry, and deinking of waste paper. This review describes production, characteristics, and biotechnological applications of microbial xylanases.


Assuntos
Bactérias/enzimologia , Bactérias/metabolismo , Reatores Biológicos/microbiologia , Endo-1,4-beta-Xilanases/metabolismo , Lignina/metabolismo , Biocombustíveis/microbiologia , Endo-1,4-beta-Xilanases/química , Fermentação/fisiologia , Engenharia Genética/métodos
13.
Anim Sci J ; 90(12): 1537-1543, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31593366

RESUMO

We conducted two feeding experiments to evaluate the effects of supplementation with either cellooligosaccharide or kraft pulp on growth performance in grazing beef calves (Japanese Black) from 4 weeks pre-weaning to 12 to 16 weeks post-weaning. In Experiment 1 (20-week duration), nine calves (2.9-month-old females) were assigned to either a control group (CON) or an experimental group (CEL) fed cellooligosaccharide at a rate of 10 g/day mixed with concentrate. Average daily weight gain tended to be greater in CEL than in CON, especially after 1 month of weaning. In Experiment 2 (16-week duration), 10 calves (2.0-month-old females) were assigned to either a control group or an experimental group (KRA) fed kraft pulp at a rate of 10% replacement of total digestible nutrients with concentrate. The proportion of fibrolytic bacteria increased and that of methanogenic Archaea decreased in the rumen microbial community composition of KRA calves in Experiment 2, whereas the decrease in Fibrobacter and Archaea was observed in CEL calves at first 4 weeks in Experiment 1. We conclude that beta-glucan prebiotic supplementation to grazing calves at pre-weaning would affect rumen microbial composition and modified rumen fermentation characteristics, leading to a better rumen environment via different means.


Assuntos
Fermentação/efeitos dos fármacos , Prebióticos/administração & dosagem , Rúmen/efeitos dos fármacos , beta-Glucanas/farmacologia , Animais , Bovinos , Dieta/veterinária , Feminino , Fermentação/fisiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Masculino , Rúmen/microbiologia , Desmame , beta-Glucanas/administração & dosagem
14.
World J Microbiol Biotechnol ; 35(10): 158, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31595344

RESUMO

Presence of bacterial contaminants at levels > 107 colony forming units per milliliter (CFU/mL) during ethanol production processes reduces the alcoholic fermentation yield by 30%. Antibiotics are currently used to control contamination, but their residues may be detected in yeast extract, restricting this by-product trade to several countries. Thus, the objective of this study was to assess antimicrobial activity of the natural compounds hops extract, 4-hydroxybenzoic acid, nisin Z, and lysozyme against Lactobacillus fermentum, Leuconostoc mesenteroides, and Saccharomyces cerevisiae, aiming development of a formula. Minimum Inhibitory Concentration of each antimicrobial was determined for bacteria and subsequently, nisin (30 mg/L) and hops extract (5 mg/L) were tested together, showing inhibitory effects combining doses of each antimicrobial that were equivalent to an eightfold reduction of their original Minimum Inhibitory Concentrations (3.75 and 0.625 mg/L, respectively), resulting in a FICIndex of 0.25. Thereon, a formula containing both compounds was developed and tested in fermentation assays, promoting reductions on bacterial population and no severe interferences in yeast viability or population even at extreme doses. Therefore, these compounds have great potential to successfully substitute conventional antibiotics in the ethanol industry.


Assuntos
Anti-Infecciosos/farmacologia , Etanol/metabolismo , Fermentação/fisiologia , Humulus/química , Extratos Vegetais/farmacologia , Antibacterianos/farmacologia , Microbiologia Industrial , Lactobacillales/efeitos dos fármacos , Lactobacillus fermentum/efeitos dos fármacos , Leuconostoc mesenteroides/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Muramidase/farmacologia , Nisina/análogos & derivados , Nisina/farmacologia , Parabenos/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharum/química
15.
PLoS Pathog ; 15(10): e1008092, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31648290

RESUMO

The viral replication proteins of plus-stranded RNA viruses orchestrate the biogenesis of the large viral replication compartments, including the numerous viral replicase complexes, which represent the sites of viral RNA replication. The formation and operation of these virus-driven structures require subversion of numerous cellular proteins, membrane deformation, membrane proliferation, changes in lipid composition of the hijacked cellular membranes and intensive viral RNA synthesis. These virus-driven processes require plentiful ATP and molecular building blocks produced at the sites of replication or delivered there. To obtain the necessary resources from the infected cells, tomato bushy stunt virus (TBSV) rewires cellular metabolic pathways by co-opting aerobic glycolytic enzymes to produce ATP molecules within the replication compartment and enhance virus production. However, aerobic glycolysis requires the replenishing of the NAD+ pool. In this paper, we demonstrate the efficient recruitment of pyruvate decarboxylase (Pdc1) and alcohol dehydrogenase (Adh1) fermentation enzymes into the viral replication compartment. Depletion of Pdc1 in combination with deletion of the homologous PDC5 in yeast or knockdown of Pdc1 and Adh1 in plants reduced the efficiency of tombusvirus replication. Complementation approach revealed that the enzymatically functional Pdc1 is required to support tombusvirus replication. Measurements with an ATP biosensor revealed that both Pdc1 and Adh1 enzymes are required for efficient generation of ATP within the viral replication compartment. In vitro reconstitution experiments with the viral replicase show the pro-viral function of Pdc1 during the assembly of the viral replicase and the activation of the viral p92 RdRp, both of which require the co-opted ATP-driven Hsp70 protein chaperone. We propose that compartmentalization of the co-opted fermentation pathway in the tombusviral replication compartment benefits the virus by allowing for the rapid production of ATP locally, including replenishing of the regulatory NAD+ pool by the fermentation pathway. The compartmentalized production of NAD+ and ATP facilitates their efficient use by the co-opted ATP-dependent host factors to support robust tombusvirus replication. We propose that compartmentalization of the fermentation pathway gives an evolutionary advantage for tombusviruses to replicate rapidly to speed ahead of antiviral responses of the hosts and to outcompete other pathogenic viruses. We also show the dependence of turnip crinkle virus, bamboo mosaic virus, tobacco mosaic virus and the insect-infecting Flock House virus on the fermentation pathway, suggesting that a broad range of viruses might induce this pathway to support rapid replication.


Assuntos
Álcool Desidrogenase/metabolismo , Piruvato Descarboxilase/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/virologia , Tombusvirus/crescimento & desenvolvimento , Replicação Viral/fisiologia , Trifosfato de Adenosina/biossíntese , Fermentação/fisiologia , Glicólise/fisiologia , Proteínas de Choque Térmico HSP70/metabolismo , Interações Hospedeiro-Patógeno/fisiologia , NAD/metabolismo , RNA Viral/biossíntese , Saccharomyces cerevisiae/metabolismo , Tabaco/virologia , Tombusvirus/genética , Replicação Viral/genética
16.
Artigo em Inglês | MEDLINE | ID: mdl-31652708

RESUMO

The effects of Cd, Cd + Fe, and Cd + Ni on the thermophilic anaerobic fermentation of corn stover and cow manure were studied in pilot experiments by investigating the biogas properties, process stability, substrate biodegradation, and microbial properties. The results showed that the addition of Fe and Ni into the Cd-containing fermentation system induced higher cumulative biogas yields and NH4+-N concentrations compared with the only Cd-added group. Ni together with Cd improved and brought forward the peak daily biogas yields, and increased the CH4 contents to 80.76%. Taking the whole fermentation process into consideration, the promoting impact of the Cd + Ni group was mainly attributed to better process stability, a higher average NH4+-N concentration, and increased utilization of acetate. Adding Fe into the Cd-containing fermentation system increased the absolute abundance of Methanobrevibacter on the 13th day, and Methanobrevibacter and Methanobacterium were found to be positively correlated with the daily biogas yield. This research was expected to provide a basis for the reuse of biological wastes contaminated by heavy metals and a reference for further studies on the influence of compound heavy metals on anaerobic fermentation.


Assuntos
Biocombustíveis , Cádmio/metabolismo , Fermentação/fisiologia , Ferro/metabolismo , Esterco , Níquel/metabolismo , Zea mays , Anaerobiose/fisiologia , Animais , Biodegradação Ambiental , Biocombustíveis/análise , Bovinos , Esterco/análise , Esterco/microbiologia , Metano/análise , Metano/metabolismo , Zea mays/metabolismo , Zea mays/microbiologia
17.
Appl Microbiol Biotechnol ; 103(21-22): 8689-8709, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31612269

RESUMO

Syngas fermentation has been successfully implemented in commercial-scale plants and can enable the biochemical conversion of the driest fractions of biomass through synthesis gas (H2, CO2, and CO). The process relies on optimized acetogenic strains able to reach and maintain high productivity of ethanol and acetate. In parallel, microbial communities have shown to be the best choice for the production of valuable medium-chain carboxylates through anaerobic fermentation of biomass, demanding low technical complexity and being able to realize simultaneous hydrolysis of the substrate. Each of the two technologies benefits from different strong points and has different challenges to overcome. This review discusses the rationales for merging these two seemingly disparate technologies by analyzing previous studies and drawing opinions based on the lessons learned from such studies. For keeping the technical demands of the resulting process low, a case is built for using microbial communities instead of pure strains. For that to occur, a shift from conventional syngas-based to "syngas-aided" anaerobic fermentation is suggested. Strategies for tackling the intricacies of working simultaneously with communities and syngas, such as competing pathways, and thermodynamic aspects are discussed as well as the stoichiometry and economic feasibility of the concept. Overall, syngas-aided anaerobic fermentation seems to be a promising concept for the biorefinery of the future. However, the effects of process parameters on microbial interactions have to be understood in greater detail, in order to achieve and sustain feasible medium-chain carboxylate and alcohol productivity.


Assuntos
Acetatos/metabolismo , Bactérias Anaeróbias/metabolismo , Reatores Biológicos/microbiologia , Ácidos Carboxílicos/metabolismo , Etanol/metabolismo , Anaerobiose , Monóxido de Carbono/metabolismo , Fermentação/fisiologia , Microbiota
18.
Nat Rev Gastroenterol Hepatol ; 16(12): 733-747, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31520080

RESUMO

The inner workings of the intestines, in which the body and microbiome intersect to influence gut function and systemic health, remain elusive. Carbon dioxide, hydrogen, methane and hydrogen sulfide, as well as a variety of trace gases, are generated by the chemical interactions and microbiota within the gut. Profiling of these intestinal gases and their responses to dietary changes can reveal the products and functions of the gut microbiota and their influence on human health. Indeed, different tools for measuring these intestinal gases have been developed, including newly developed gas-sensing capsule technology. Gases can, according to their type, concentration and volume, induce or relieve abdominal symptoms, and might also have physiological, pathogenic and therapeutic effects. Thus, profiling and modulating intestinal gases could be powerful tools for disease prevention and/or therapy. As the interactions between the microbiota, chemical constituents and fermentative substrates of the gut are principally influenced by dietary intake, altering the diet, which, in turn, changes gas profiles, is the main therapeutic approach for gastrointestinal disorders. An improved understanding of the complex interactions within the intestines that generate gases will enhance our ability to prevent, diagnose, treat and monitor many gastrointestinal disorders.


Assuntos
Dieta , Gases/metabolismo , Gastroenteropatias/fisiopatologia , Testes Respiratórios/métodos , Técnicas de Diagnóstico do Sistema Digestório , Fermentação/fisiologia , Gases/análise , Gastroenteropatias/microbiologia , Microbioma Gastrointestinal/fisiologia , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/microbiologia , Homeostase/fisiologia , Humanos
19.
Arch Anim Nutr ; 73(6): 485-504, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31544530

RESUMO

The same food formulation processed to obtain two different starch gelatinisations (SG) and resistant starch (RS) contents was evaluated in old and adult dogs, regarding apparent total tract digestibility (ATTD) of nutrients, fermentation products in faeces, and postprandial glucose and insulin responses. A diet with corn was ground and extruded in two different ways, obtaining Low RS (2.2 g/kg DM; 99.9% of SG) and High RS (15.3 g/kg DM; 62.6% of SG). Each diet was fed to adults (4.0 ± 0.7 years) or old beagle dogs (11.5 ± 0.4 years) in a 2 (ages) x 2 (RS amounts) factorial arrangement with 8 dogs per food. Data were evaluated by analysis of variance, and postprandial responses by analysis of variance of repeated measurements over time (p < 0.05). Diet × age interaction was observed for protein ATTD, with lower values for old dogs fed High RS than those for the other treatments (p < 0.05). No age or diet effect was verified for the ATTD of other nutrients and faecal score. Faecal moisture and pH were higher for adults than that for old dogs (p < 0.05). The High RS food increased acetate, propionate and butyrate concentrations in faeces, regardless of age (p < 0.01). Old dogs presented lower acetate and total short-chain fatty acids (SCFA) and higher lactate and ammonia than adults (p < 0.05). Only for old dogs the intake of the High RS food reduced ammonia and increased faecal lactate (p < 0.05). An age × diet interaction was verified for glucose postprandial response, with lower values for old dogs fed High RS food (p < 0.05), while no differences were found for the other treatments. Old dogs had higher postprandial insulin secretion regardless of the diet (p < 0.05), and lower insulin increment at 180 min after the meal when fed the Low RS than when fed the High RS food (p < 0.05). In conclusion, the diet with lower SG and higher RS improved the intestinal microenvironment, with higher butyrate and total SCFA without altering faeces production or score. Old dogs presented less acetate and total SCFA and higher lactate and ammonia in faeces than adults. The High RS food increased lactate and reduced ammonia in faeces of old dogs, with possible positive influences for gut health. Old dogs had higher postprandial insulin secretion than that of adults to maintain blood glucose, and the diet with higher RS content reduced the postprandial glucose response of old dogs.


Assuntos
Carboidratos da Dieta/metabolismo , Digestão/fisiologia , Cães/fisiologia , Fezes/química , Fermentação/fisiologia , Amido/metabolismo , Fatores Etários , Fenômenos Fisiológicos da Nutrição Animal , Animais , Glicemia/metabolismo , Digestão/efeitos dos fármacos , Feminino , Fermentação/efeitos dos fármacos , Insulina/sangue , Masculino , Período Pós-Prandial , Amido/administração & dosagem , Amido/química
20.
Mol Biol Rep ; 46(6): 5995-6002, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31432358

RESUMO

A consistent kojic acid producing fungal strain has been isolated from rice husk using glucose-peptone medium. The isolate was identified as Aspergillus sojae SSC-3 on 18S rDNA analysis. A. sojae was capable of producing substantially good amount of kojic acid, however the production was varying from batch to batch. In order to obtain consistent, repeated and high levels of kojic acid, monospore isolation procedures was adopted. The highest production of kojic acid obtained was 12 ± 2 g/L in 120 h with sucrose (10%) and yeast extract (0.5%) as carbon and nitrogen source respectively. The process was scale up to 10 L fermenter size which repeatedly resulted in the production of 18 ± 2 g/L of kojic acid in 96 h. Kojic acid was recovered (> 82%) from the fermentation broth with > 99% purity. Best to our knowledge this is the first report were kojic acid production is reported from Aspergillus sojae strain.


Assuntos
Aspergillus/metabolismo , Pironas/isolamento & purificação , Pironas/metabolismo , Aspergillus/isolamento & purificação , Carbono/metabolismo , Fermentação/fisiologia , Glucose/metabolismo , Nitrogênio/metabolismo , Oryza/microbiologia , Peptonas/metabolismo , Sacarose/metabolismo
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