Production and characterization of thermostable cellulases from Streptomyces transformant T3-1

A total of 26 thermophilic isolates, selected from a compost of agricultural waste, which was mostly composed of vegetable, corncob and rice straw, were cultivated at 50 °C for further studies of thermostable cellulase production. The thermostable cellulase gene from the chromosomal DNA of actinomycetes isolate no. 10 was shotgun-cloned and transformed into Streptomyces sp. IAF 10-164. A transformant, T3-1, was found to be a good strain for the production of thermostable cellulases. Cultivation of T3-1 in modified Mandels–Reese broth containing 1% carboxymethylcellulose (CMC)-sodium salt and the optimal condition for microbial growth were studied. Batch cultivation in a flask revealed that CMCase and Avicelase production reached the maximum between the third to fifth day, whereas maximum -glucosidase production occurred on the ninth day. Microbial biomass increased from the first day to the fifth day and then decreased. The crude enzyme had the highest activity at 50 °C and at pH 6.5. The enzyme was shown to be a thermostable cellulase whose activities were stable at 50 °C for more than 7 days.     

The effect of the red wine polyphenol resveratrol on a rat model of biliary obstructed cholestasis: involvement of anti-apoptotic signalling, mitochondrial biogenesis and the induction of autophagy

Mitochondria are known to be involved in cholestatic liver injury. The potential protective effect of resveratrol in cholestatic liver injury and the possible roles of autophagy and apoptosis induction in this process are not yet clear. The aim of this study is to determine whether resveratrol administration after bile duct ligation can reduce cholestasis-induced liver injury through modulating apoptosis, mitochondrial biogenesis and autophagy. A rat model of cholestasis was established by bile duct ligation (BDL) and compared with a sham group receiving laparotomy without BDL, with resveratrol or control treatments following BDL. The expression of proteins involved in the apoptotic and autophagic pathways were analyzed by western blotting. Apoptosis was examined by TUNEL staining. In the resveratrol/BDL group LC3-II upregulation persisted for 1-7 days, Bax was downregulated and catalase was upregulated at 3-7 days after resveratrol treatment. The decline in mitochondrial DNA copy number was reversed at 3-7 days. Caspase 3 expression was significantly downregulated at 3-7 days in the resveratrol group. TUNEL staining showed significant numbers of apoptotic liver cells appeared in livers 3-7 days after BDL and that was decreased by resveratrol treatment. Our results indicate that early resveratrol treatment reverses impaired liver function within hours of BDL.