Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Poult Sci ; 101(9): 102040, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35917674

RESUMEN

This study was conducted to investigate the effect of PUFA-enriched rubber (Hevea brasiliensis) seed oil (RSO) supplementation in diets on the productive performance, plasma biochemical parameters, immune response, and inflammation in lipopolysaccharide (LPS)-challenged laying hens. Two hundred and forty 25-wk-old Lohmann Brown laying hens were randomly divided into 5 treatments, each including 4 replicates with 12 birds per replicate. The control group and LPS-challenged group were fed a corn-soybean-basal diet; 3 RSO-supplemented groups were fed experimental diets containing 1, 2, and 4% RSO for a feeding period of 4 wk. On the 15, 18, 21, 24, and 27 d of the RSO supplementation period of 4 wk, hens were injected intraperitoneally with LPS at 1 mg/kg body weight (challenge group and RSO-supplemented groups) or with the same amount of saline (control group). The results showed that the addition of RSO promoted laying performance by increasing egg production, total egg weight, daily egg mass, and feed intake in comparison to the LPS-challenged laying hens (P < 0.05). In addition, compared with laying hens stimulated with LPS, the analysis of blood cell and plasma parameters revealed that hens in RSO-supplemented groups had significantly lower levels (P < 0.05) of white blood cells (WBC), lymphocytes (LYM), aspartate aminotransferase (AST) activity, immunoglobulin A (IgA), triiodothyronine (T3), interleukin-2 (IL-2), and tumor necrosis factor-α (TNF-α). Further, RSO supplementation significantly reduced the mRNA expression of toll-like receptor 4 (TLR4), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), interleukin-6 (IL-6), and interleukin-1ß (IL-1ß) of the ileum, spleen, and liver in LPS-challenged laying hens (P < 0.05), suggesting that the anti-inflammatory mechanism of RSO is related to the TLR4/NF-κB signaling pathway. In conclusion, RSO supplementation in diets could improve laying performance, attenuate immunological stress, and inhibit the inflammatory response in LPS-challenged laying hens, especially at the dietary inclusion of 4% RSO. This study will provide an insight into the application of RSO to positively contribute to overall health and welfare in laying hens.


Asunto(s)
Fenómenos Fisiológicos Nutricionales de los Animales , Hevea , Alimentación Animal/análisis , Animales , Pollos/fisiología , Dieta/veterinaria , Suplementos Dietéticos/análisis , Femenino , Lipopolisacáridos , FN-kappa B/metabolismo , Aceites de Plantas/metabolismo , Goma/metabolismo , Receptor Toll-Like 4/metabolismo
2.
Food Nutr Res ; 662022.
Artículo en Inglés | MEDLINE | ID: mdl-35721808

RESUMEN

Background: Obesity has become a global epidemic recognized by the World Health Organization. Probiotics supplementation has been shown to contribute to improve lipid metabolism. However, mechanisms of action of probiotics against obesity are still not clear. Lactobacillus plantarum FRT4, a probiotic previously isolated from a kind of local yogurt, had good acid and bile salt tolerance and lowered cholesterol in vitro. Objective: This study aimed to evaluate the effect of L. plantarum FRT4 on serum and liver lipid profile, liver metabolomics, and gut microbiota in mice fed with a high-fat diet (HFD). Design: Mice were fed with either normal diet or HFD for 16 weeks and administered 0.2 mL of 1 × 109 or 1 × 1010 CFU/mL dosage of L. plantarum FRT4 during the last 8 weeks of the diet. Cecal contents were analyzed by 16S rRNA sequencing. Hepatic gene expression and metabolites were detected by real-time quantitative polymerase chain reaction (PCR) and metabolomics, respectively. Results: L. plantarum FRT4 intervention significantly reduced the HFD-induced body weight gain, liver weight, fat weight, serum cholesterol, triglyceride, and alanine aminotransferase (ALT) levels in the liver (P < 0.05). Liver metabolomics demonstrated that the HFD increased choline, glycerophosphocholine, and phosphorylcholine involved in the glycerophospholipid metabolism pathway. All these changes were reversed by FRT4 treatment, bringing the levels close to those in the control group. Further mechanisms showed that FRT4 favorably regulated gut barrier function and pro-inflammatory biomediators. Furthermore, FRT4 intervention altered the gut microbiota profiles and increased microbial diversity. The relative abundances of Bacteroides, Parabateroides, Anaerotruncus, Alistipes, Intestinimonas, Butyicicoccus, and Butyricimonas were significantly upregulated. Finally, Spearman's correlation analysis revealed that several specific genera were strongly correlated with glycerophospholipid metabolites (P < 0.05). Conclusions: These findings suggested that L. plantarum FRT4 had beneficial effects against obesity in HFD-induced obese mice and can be used as a potential functional food for the prevention of obesity.

3.
Nutrients ; 14(7)2022 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-35405962

RESUMEN

Rubber seed oil (RSO) is a typical PUFA-enriched plant oil, but it has not been widely used as a healthy edible oil resource due to the lack of understanding of its nutritional values, health biological effects, and action mechanisms. This work was conducted to characterize the basic physicochemical properties, evaluate the antioxidant and anti-inflammatory properties, and explore the involved mechanisms of RSO in LPS-induced RAW 264.7 cells. In the present study, the basic physicochemical parameters of RSO indicated that RSO has good qualities as a potential edible plant oil resource. In LPS-induced macrophages, RSO supplementation displayed a significant antioxidant effect by decreasing ROS and MDA levels as well as elevating T-AOC. In addition, RSO supplementation showed an anti-inflammatory effect by reducing the production of NO, IL-1ß, IL-6, and TNF-α while promoting the production of IL-10. Moreover, RSO supplementation decreased the mRNA expression of IL-6, IL-1ß, TNF-α, iNOS, and MCP-1 genes while increasing the mRNA expression of the IL-10 gene. Furthermore, RSO supplementation increased Nrf2 protein expression and up-regulated antioxidant genes (HO-1 and NQO-1), which was accompanied by the decrease in TLR4 protein expression and NF-κB p65 phosphorylation as well as IκBα phosphorylation. This study provided some insight into the applications of RSO as a healthy edible oil resource.


Asunto(s)
Antioxidantes , Lipopolisacáridos , Animales , Antiinflamatorios/uso terapéutico , Antioxidantes/metabolismo , Grasas Insaturadas , Inflamación/tratamiento farmacológico , Interleucina-10/metabolismo , Interleucina-6/metabolismo , Lipopolisacáridos/efectos adversos , Macrófagos/metabolismo , Ratones , FN-kappa B/metabolismo , Células RAW 264.7 , ARN Mensajero/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo
4.
Foods ; 11(2)2022 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-35053915

RESUMEN

Lactobacillus plantarum is considered a potential probiotic supplementation for treating obesity. However, the underlying molecular mechanism is poorly understood. Our previous study displayed that L. plantarum FRT4 alleviated obesity in mice fed a high-fat diet (HFD) through ameliorating the HFD-induced gut microbiota dysbiosis. To explore the roles of FRT4 in obesity prevention, in this study, we investigated changes in serum metabolomic phenotype by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS) and analyzed the pathway of HFD-fed Kunming female mice orally administered with FRT4 for eight weeks. Using orthogonal partial least squares discriminant analysis (OPLS-DA), metabolite patterns with significant changes were observed. 55 metabolites including phosphatidylcholine, lysophophatidylcholine, sphingomyelin, serotonin, indole-3-methyl aceta, indole-3-carbinol, indole-5,6-quino, 11,12-DHET, prostaglandin B2, leukotriene B4, and 3-hydroxybenzoic acid were identified as potential biomarkers associated with obesity, which were mainly involving in glycerophospholipid metabolism, tryptophan metabolism, and arachidonic acid metabolism. Perturbations of 14 biomarkers could be regulated by FRT4 intervention. These metabolites may serve as valuable biomarkers to understand the mechanisms by which intake of diets containing FRT4 contributes to the treatment or prevention of obesity. Thus, FRT4 can be a promising dietary supplement for the prevention of HFD-induced obesity.

5.
Food Chem ; 301: 125198, 2019 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-31374533

RESUMEN

The experiment was conducted to evaluate the effects of five rubber seed oil (RSO) levels (0, 1%, 2%, 4%, and 6%) on hens laying performance, egg quality, and yolks fatty acid composition and cholesterol contents. Three hundred and sixty 30-week-old Lohmann Brown laying hens were allotted to 5 groups. The results showed that the egg production was increased in 4% RSO group (P < 0.05), but egg quality parameters and the contents of dry matter, lipid, and protein in yolks were not influenced among treatments (P > 0.05). Yolk cholesterol contents were reduced in RSO supplemental groups (P < 0.05). The concentration of total n-3 PUFA in yolks increased gradually while the ratio of n-6/n-3 decreased gradually with increasing dietary RSO levels (P < 0.001). In conclusion, dietary RSO supplementation increased yolk n-3 PUFA levels, improved yolk color, and reduced yolk cholesterol contents without negative influence on laying performance parameters.


Asunto(s)
Alimentación Animal , Pollos , Colesterol/metabolismo , Yema de Huevo/química , Grasas Insaturadas/farmacología , Ácidos Grasos Omega-3/metabolismo , Animales , Pollos/metabolismo , Colesterol/análisis , Suplementos Dietéticos , Yema de Huevo/metabolismo , Ácidos Grasos Omega-3/análisis , Femenino , Calidad de los Alimentos , Almacenamiento de Alimentos , Lípidos/análisis
6.
Biomed Chromatogr ; 33(12): e4687, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31441946

RESUMEN

In recent years, the fingerprint of high-performance liquid chromatography has been extensively applied in the identification and quality control of traditional Chinese medicine. It can be a potential protocol for assessing the authenticity, stability and consistency of traditional Chinese medicine and guaranteeing the expected biological activity. In this paper, a method using high-performance liquid chromatography to identify and control the quality of the extract of Taraxacum mongolicum Hand.-Mazz. (TME) was established. With this method, the correlation coefficients of the similarity of 10 batches were ≥0.994. The TME displayed a steady proliferative effect in Lactobacillus plantarum. In brief, this study successfully built a reliable, simple and efficient method to control and confirm the quality and the stability of biological activity of the TME.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Lactobacillus plantarum/efectos de los fármacos , Extractos Vegetales , Taraxacum/química , Cromatografía Líquida de Alta Presión , Extractos Vegetales/análisis , Extractos Vegetales/química , Extractos Vegetales/farmacología , Extractos Vegetales/normas , Control de Calidad , Reproducibilidad de los Resultados
7.
Food Funct ; 10(5): 2340-2346, 2019 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-31020296

RESUMEN

Disinhibition of antibiotics promotes the use of probiotics, prebiotics, immune enhancers, and plant extracts. We investigated the effects of stevioside on growth performance, nutrient digestibility, serum parameters, and intestinal microflora in broilers. Eight hundred ninety-six one-day-old male Arbor Acres broiler chicks (average body weight 48.36 ± 0.21 g) were allotted to 1 of 7 experimental treatments. Treatments consisted of: (1) control (basal diet without supplemental stevioside), (2) 100 mg kg-1 supplemental stevioside (S100), (3) 200 mg kg-1 supplemental stevioside (S200), (4) 400 mg kg-1 supplemental stevioside (S400), (5) 800 mg kg-1 supplemental stevioside (S800), (6) 1600 mg kg-1 supplemental stevioside (S1600), and (7) 3200 mg kg-1 supplemental stevioside (S3200). Performance was not affected by stevioside concentration. Dietary stevioside supplementation increased the digestibility of calcium (P < 0.05) and tended to improve phosphorus digestibility (P = 0.0730). There was a linear effect of dietary stevioside on the concentration of serum glucose (P < 0.05). The serum IgG and IgA levels were linearly increased by stevioside supplementation (P < 0.05). In the ileal digesta, the concentration of E. coli decreased with increasing dietary stevioside supplementation (P < 0.05). On the contrary, dietary stevioside supplementation increased the concentration of Bifidobacteria (P < 0.01) and tended to improve the concentration of Lactobacillus (P = 0.0791). In conclusion, our data suggest that stevioside supplementation could improve the calcium and phosphorus digestibility and decrease blood glucose levels of broilers. Additionally, dietary stevioside supplementation significantly increased Bifidobacteria in the cecal digesta, and decreased E. coli.


Asunto(s)
Pollos/crecimiento & desarrollo , Suplementos Dietéticos/análisis , Diterpenos de Tipo Kaurano/administración & dosificación , Microbioma Gastrointestinal/efectos de los fármacos , Glucósidos/administración & dosificación , Alimentación Animal/análisis , Animales , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Pollos/sangre , Pollos/microbiología , Digestión/efectos de los fármacos , Femenino , Íleon/efectos de los fármacos , Íleon/metabolismo , Íleon/microbiología , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Masculino , Prebióticos/análisis
8.
Biomed Chromatogr ; 32(12): e4354, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30074251

RESUMEN

Similarity evaluation of complicated chromatographic profiles is a potential protocol for the identification and quality control of herbal medicinal products to ensure their biological activity. In this work, a high-performance liquid chromatography method was established for controlling the batch quality of the extract from Portulaca oleracea L. Using this method, the coefficients of correlation of the similarity of 10 batches extract of P. oleracea L. were ≥ 0.97. The 10 batch extracts from P. oleracea L. possessed stable antiproliferative activity in Aspergillus flavus. The antiproliferative activity stability is correlated with the stability quality of the of the extract from P. oleracea L. Therefore, the present study successfully set up a sensitive and efficient method which might be used to guarantee stable biological activity of the extract from P. oleracea L.


Asunto(s)
Antifúngicos/normas , Aspergillus flavus/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Extractos Vegetales/normas , Portulaca/química , Antifúngicos/química , Antifúngicos/farmacología , Extractos Vegetales/química , Extractos Vegetales/farmacología , Plantas Medicinales/química , Control de Calidad , Reproducibilidad de los Resultados
9.
Food Chem ; 188: 569-75, 2015 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26041232

RESUMEN

Polygalacturonase is one of the most important industrial pectinases. To enrich the genetic resources and develop new enzyme candidates, three polygalacturonase genes (Nfpg I-III) of glycosyl hydrolase family 28 were cloned from Neosartorya fischeri P1 and functionally expressed in Pichia pastoris. The purified recombinant proteins exhibited some distinguished properties. In comparison with other counterparts, NfPG I showed the highest specific activity (40, 123 U/mg), NfPG II had the highest temperature optimum (65 °C), and the pH optimum of NfPG III was the lowest (3.5). The orders of their thermostability and resistance to chemicals tested were NfPG II>NfPG III>NfPG I and NfPG II>NfPG I>NfPG III, respectively. Combinations of these enzymes showed better performance than individuals in the processing and clarification of apple and strawberry juice. These results suggest that N. fischeri polygalacturonases have great application potentials in the food industry for juice production.


Asunto(s)
Jugos de Frutas y Vegetales/análisis , Neosartorya/enzimología , Pectinas/química , Poligalacturonasa/química
10.
J Agric Food Chem ; 62(52): 12686-94, 2014 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-25494480

RESUMEN

Thermophilic endo-polygalacturonases with high catalytic efficiency are of great interest in the food and feed industries. This study identified an endo-polygalacturonase gene (pg7fn) of glycoside hydrolase family 28 in the thermophilic fungus Thielavia arenaria XZ7. Recombinant PG7fn produced in Pichia pastoris is distinguished from other enzyme counterparts by its high functional temperature (60 °C) and specific activity (34382 ± 351 U/mg toward polygalacturonic acid). The enzyme exhibited good pH stability (pH 3.0-8.0) and resistance to pepsin and trypsin digestion and had a significant effect on disaggregation of soybean meal. Addition of 1 U/g PG7fn increased the pectin bioavailability by 19.33%. The excellent properties described above make PG7fn valuable for applications in the food and feed industries. Furthermore, a comparative study showed that N-glycosylation improved the thermostability and catalytic efficiency of PG7fn.


Asunto(s)
Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Poligalacturonasa/química , Poligalacturonasa/genética , Sordariales/enzimología , Secuencia de Aminoácidos , Alimentación Animal/análisis , Biocatálisis , Clonación Molecular , Estabilidad de Enzimas , Industria de Alimentos , Proteínas Fúngicas/metabolismo , Cinética , Modelos Moleculares , Datos de Secuencia Molecular , Pectinas/metabolismo , Pichia/genética , Poligalacturonasa/metabolismo , Alineación de Secuencia , Sordariales/química , Sordariales/genética
11.
Appl Microbiol Biotechnol ; 98(11): 5019-28, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24584459

RESUMEN

A multimodular pectinase of glycoside hydrolase family 28, S6A, was identified in Penicillium oxalicum SX6 that consists of an N-terminal catalytic domain of pectin methylesterase, a Thr/Ser-rich linker region, and a C-terminal catalytic domain of polygalacturonase. Recombinant S6A and its two derivatives, S6PE (the catalytic domain of pectin methylesterase) and S6PG (the catalytic domain of polygalacturonase), were produced in Pichia pastoris. S6A was a bifunctional protein and had both pectin methylesterase and polygalacturonase activities. Three enzymes showed similar biochemical properties, such as optimal pH and temperature (pH 5.0 and 50 °C) and excellent stability at pH 3.5-6.0 and 40 °C. Most metal ions tested (Na(+), K(+), Ca(2+), Li(+), Co(2+), Cr(3+), Ni(2+), Cu(2+), Mn(2+),Mg(2+), Fe(3+), Zn(2+), and Pb(2+)) enhanced the pectin methylesterase activities of S6PE and S6A, but had little or inhibitory effects on the polygalacturonase activities of S6A and S6PG. In comparison with most fungal pectin methylesterases, S6A had higher specific activity (271.1 U/mg) towards 70 % DM citrus pectin. When S6PE and S6PG were combined at the activity ratio of 1:4, the most significant synergistic effect was observed in citrus pectin degradation and degumming of sisal fiber, which is comparable with the performance of S6A (95 v.s. 100 % and 16.9 v.s. 17.2 %, respectively). To the best of our knowledge, this work represents the first report of gene cloning, heterologous expression, and biochemical characterization of a bifunctional pectinase with separate catalytic domains.


Asunto(s)
Hidrolasas de Éster Carboxílico/genética , Hidrolasas de Éster Carboxílico/metabolismo , Penicillium/enzimología , Poligalacturonasa/genética , Poligalacturonasa/metabolismo , Hidrolasas de Éster Carboxílico/química , Hidrolasas de Éster Carboxílico/aislamiento & purificación , Dominio Catalítico , Citrus/química , Clonación Molecular , ADN de Hongos/química , ADN de Hongos/genética , Activadores de Enzimas/metabolismo , Estabilidad de Enzimas , Expresión Génica , Concentración de Iones de Hidrógeno , Metales/metabolismo , Datos de Secuencia Molecular , Pectinas/metabolismo , Penicillium/genética , Poligalacturonasa/química , Poligalacturonasa/aislamiento & purificación , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Análisis de Secuencia de ADN , Temperatura
12.
PLoS One ; 7(7): e40940, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22815874

RESUMEN

BACKGROUND: Efficient degradation of pectin in the rumen is necessary for plant-based feed utilization. The objective of this study was to characterize the diversity, abundance, and functions of pectinases from microorganisms in the sheep rumen. METHODOLOGY/PRINCIPAL FINDINGS: A total of 103 unique fragments of polygalacturonase (PF00295) and pectate lyase (PF00544 and PF09492) genes were retrieved from microbial DNA in the rumen of a Small Tail Han sheep, and 66% of the sequences of these fragments had low identities (<65%) with known sequences. Phylogenetic tree building separated the PF00295, PF00544, and PF09492 sequences into five, three, and three clades, respectively. Cellulolytic and noncellulolytic Butyrivibrio, Prevotella, and Fibrobacter species were the major sources of the pectinases. The two most abundant pectate lyase genes were cloned, and their protein products, expressed in Escherichia coli, were characterized. Both enzymes probably act extracellularly as their nucleotide sequences contained signal sequences, and they had optimal activities at the ruminal physiological temperature and complementary pH-dependent activity profiles. CONCLUSION/SIGNIFICANCE: This study reveals the specificity, diversity, and abundance of pectinases in the rumen ecosystem and provides two additional ruminal pectinases for potential industrial use under physiological conditions.


Asunto(s)
Variación Genética , Poligalacturonasa/genética , Polisacárido Liasas/genética , Rumen/microbiología , Animales , Clonación Molecular , ADN Bacteriano/genética , Ecosistema , Escherichia coli/metabolismo , Concentración de Iones de Hidrógeno , Modelos Genéticos , Pectinas/metabolismo , Filogenia , Análisis de Secuencia de ADN , Ovinos , Oveja Doméstica/fisiología
13.
Curr Microbiol ; 63(5): 408-15, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21853317

RESUMEN

Microbial phytases play a major role in the mineralization of organic phosphorous, especially in symbiotic plants and animals. In this study, we identified two types of phytases in Serratia sp. TN49 that was harbored in the gut of Batocera horsfieldi (Coleoptera) larvae. The two phytases, an acidic histidine acid phosphatase (PhyH49) and an alkaline ß-propeller phytase (PhyB49), shared low identities with known phytases (61% at most). PhyH49 and PhyB49 produced in Escherichia coli exhibited maximal activities at pH 5.0 (60°C) and pH 7.5-8.0 (45°C), respectively, and are complementary in phytate degradation over the pH range 2.0-9.0. Serratia sp. TN49 harboring both PhyH49 and PhyB49 might make it more adaptive to environment change, corresponding to the evolution trend of microorganism.


Asunto(s)
6-Fitasa/metabolismo , Proteínas Bacterianas/metabolismo , Escarabajos/microbiología , Serratia/enzimología , 6-Fitasa/química , 6-Fitasa/genética , Secuencia de Aminoácidos , Animales , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Escarabajos/crecimiento & desarrollo , Estabilidad de Enzimas , Tracto Gastrointestinal/microbiología , Larva/microbiología , Datos de Secuencia Molecular , Alineación de Secuencia , Serratia/química , Serratia/genética , Serratia/aislamiento & purificación , Especificidad por Sustrato
14.
Environ Microbiol ; 13(3): 747-57, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21105982

RESUMEN

A novel class of cysteine phytase showing ability to degrade phytate has recently been isolated from rumen bacteria. To expand our knowledge of this enzyme class, a total of 101 distinct cysteine phytase gene fragments were identified from the ruminal genomic DNA of Bore goats and Holstein cows, and most of them shared low identities (< 50%) with known sequences. By phylogenetic analysis, these sequences were separated into three clusters that showed substantial diversity. The two most abundant cysteine phytase genes of goat rumens were cloned and their protein products were characterized. Four findings were revealed based on our results. (i) Compared with soil and water environment, where ß-propeller phytase is the most important phytate-degrading enzyme, cysteine phytase is the major phytate-degrading enzyme in the anaerobic ruminal environment. (ii) Cysteine phytase fragments in the rumen contents of goat and cow have the same diversity profile, although most of the sequences and their abundance differ in the two species. (iii) Each species has their respective high-abundance genes, which may play major roles for phytate degradation. (iv) Compared with previously reported cysteine phytases that have pH optimum at 4.5, the pH optima of the two most abundant secreted goat cysteine phytases are 6.5 and 6.0, which are within the pH range found in the rumens. This study provides valuable information about the diversity, abundance and enzymatic properties of the ruminal cysteine phytases and emphasizes the important role(s) of these cysteine phytases probably in the terrestrial cycle of phosphorus.


Asunto(s)
6-Fitasa/genética , Bacterias/enzimología , Ácido Fítico/metabolismo , Rumen/microbiología , 6-Fitasa/química , 6-Fitasa/metabolismo , Secuencia de Aminoácidos , Animales , Bovinos , Cisteína/análisis , Cabras , Datos de Secuencia Molecular , Fósforo/metabolismo , Microbiología del Suelo
15.
Appl Environ Microbiol ; 75(6): 1508-16, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19151187

RESUMEN

Phytate is the most abundant organic phosphorus compound in nature, and microbial mineralization of phytate by phytase is a key process for phosphorus recycling in the biosphere. In the present study, beta-propeller phytase (BPP) gene fragments were readily amplified from the intestinal contents of grass carp (Ctenopharyngodon idellus) directly or from phytate-degrading isolates from the same source, confirming the widespread occurrence of BPP in aquatic communities. The amounts of sequences collected using these two methods differed (88 distinct genes versus 10 isolates), but the sequences showed the same general topology based on phylogenetic analysis. All of the sequences fell in five clusters and were distinct from those of Anabaena, Gloeobacter, Streptomyces, Flavobacterium, Prosthecochloris, and Desulfuromonas, which have never been found in the grass carp intestine. Analysis of the microbial diversity by denaturing gradient gel electrophoresis demonstrated that unculturable bacteria were dominant bacteria in the grass carp intestine and thus the predominant phytate-degrading organisms. The predominant cultured species corresponding to the phytate-degrading isolates, Pseudomonas, Bacillus and Shewanella species, might be the main source of known BPPs. A phytase from Brevundimonas was first obtained from cultured species. Combining our results with Lim et al.'s inference that phytate-mineralizing bacteria are widely distributed and highly diverse in nature (B. L. Lim, P. Yeung, C. Cheng, and J. E. Hill, ISME J. 1:321-330, 2007), we concluded that BPP is the major phytate-degrading enzyme in nature, that most of this enzyme might originate from unculturable bacteria, and that the distribution of BPP may be related to the type of niche. To our knowledge, this is the first study to experimentally estimate BPP diversity in situ.


Asunto(s)
6-Fitasa/genética , Bacterias/clasificación , Bacterias/enzimología , Carpas/microbiología , Contenido Digestivo/microbiología , Fósforo/metabolismo , Ácido Fítico/metabolismo , Secuencia de Aminoácidos , Animales , Bacterias/genética , Bacterias/aislamiento & purificación , Análisis por Conglomerados , Datos de Secuencia Molecular , Filogenia , Alineación de Secuencia , Análisis de Secuencia de ADN , Homología de Secuencia
16.
Sheng Wu Gong Cheng Xue Bao ; 25(12): 1844-51, 2009 Dec.
Artículo en Chino | MEDLINE | ID: mdl-20352959

RESUMEN

Enzymes can degrade the anti-nutrient factors in feedstuff, increase nutrient digestibility, and reduce pollution to environment, and have been widely supplemented in animal feedstuff. However, the use of enzymes is limited because of their undesirable properties, such as thermoliability and susceptibility against protease digestions. And its commercialization is also limited by low production efficiency and high cost. Therefore, the focuses for future enzyme development will be: (1) to obtain novel enzymes with better properties by high-throughput screening of enzyme encoding genes, especially those from extreme and special environments; (2) to improve enzyme properties using directed mutagenesis and protein engineering methods; (3) to achieve high-level fermentation of enzymes by heterogonous expression and optimization of codons, vectors and fermentation conditions; (4) to determine the effect of enzymes to animals and utilize enzymes efficiently.


Asunto(s)
6-Fitasa , Alimentación Animal , Péptido Hidrolasas , 6-Fitasa/genética , 6-Fitasa/metabolismo , 6-Fitasa/farmacología , Animales , Suplementos Dietéticos , Lipasa/genética , Lipasa/metabolismo , Lipasa/farmacología , Péptido Hidrolasas/genética , Péptido Hidrolasas/metabolismo , Péptido Hidrolasas/farmacología , Ingeniería de Proteínas
17.
Biotechnol Lett ; 29(4): 659-67, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17206370

RESUMEN

The gene, xynB, from Streptomyces olivaceoviridis A1 encoding xylanase, XYNB, with a high specific activity for xylan, was transformed into potato (Solanum tuberosum L.) by Agrobacterium tumefaciens. The integration of xynB into genomic DNA was confirmed by PCR and reverse transcriptase-PCR. The gene was expressed under the control of a constitutive double cauliflower mosaic virus (CaMV) 35S promoter. Both SDS-PAGE and western blot analysis showed high levels of expression of the 21 kDa and 31 kDa XYNB proteins in transgenic potato plants transformed by the binary vectors pBinXy and signal peptide contained pBinSPXy, respectively. The recombinant XYNB protein was present at up to 5% of total soluble leaf protein in the cytoplasm. In transgenic leaf and tuber extracts, xylanase activity was up to 87 micromol min(-1) g(-1) fresh leaf (9.7 micromol min(-1) mg(-1) total soluble protein). The xylanase was stable at 60 degrees C and 70 degrees C in buffers (pH 5.2) for 5 min. Furthermore, the xylanase enzymatic activity remained virtually unchanged over several generations of potato. These results demonstrate that the transgenic potato can be used to produce recombinant xylanase with high specific enzyme activity and can potentially be an alternative to present-day xylanase additives to animal feed.


Asunto(s)
Endo-1,4-beta Xilanasas/química , Plantas Modificadas Genéticamente/enzimología , Solanum tuberosum/enzimología , Streptomyces/enzimología , Endo-1,4-beta Xilanasas/genética , Endo-1,4-beta Xilanasas/metabolismo , Activación Enzimática , Regulación Enzimológica de la Expresión Génica/fisiología , Regulación de la Expresión Génica de las Plantas/fisiología , Solanum tuberosum/genética , Streptomyces/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA