产自Aspergillus sp.DLCS-F18的嗜酸嗜热纤维素酶及其酶学性质

纤维素酶在饲料、造纸、纺织和纤维素乙醇生产等领域有重要用途,因而备受关注.使用稻草为唯一碳源进行纤维素降解微生物的富集,从云南大理苍山地区的土壤样品中筛选获得1株纤维素降解真菌DLCS-F18,其适宜生长温度为15-40℃、pH 2.0-13.0.通过形态学和ITS rRNA分子生物学鉴定,菌株DLCS-F18被鉴定为...

Thermoacidophilic cellulase produced by Aspergillus sp.DLCS-F18 and its cellulose-hydrolytic characteristics

Cellulase has attracted much attention because of its important applications in feed, paper making, textile and cellulosic ethanol production. In this study, straw was used as the sole carbon source for enrichment of cellulose degrading microorganisms, and a cellulose degrading fungus Aspergillussp. DLCS-F18 was obtained from soil sample in Cangshan mountain, Dali City, Yunnan Province. Its growth temperature and pH range were 15-40°C and 2.0-13.0, respectively. The strain was identified based on morphology and ITS rRNA molecular data. The optimum pH and temperature of cellulase production was 4.0 and 65°C, respectively. The cellulase maintained its activity of 85% at pH 3.0 and reached the maximum activity of over 70% at 75°C. The activity was stable under the condition of the presence of most metal ions and enzyme inhibitors. The highest activity of 84h-fermented supernatant degrading sodium carboxymethyl cellulose (CMC-Na) was (5.4±0.2)U/mL. These indicate that the cellulase secreted by DLCS-F18 are thermoacidophilic, and the strain has a broad application prospect in lignocellulosic hydrolysis and animal feed.