酒醅中高产纤维素酶菌株的筛选及其酶学性质

纤维素酶具有广阔的应用前景,不同来源的纤维素酶具有各自的特点。本研究以浓香型酒醅为材料筛选产纤维素酶微生物,以期望用于酒糟纤维素的降解和利用。研究以羧甲基纤维素钠刚果红培养基对产酶菌株进行筛选,获得一株高产纤维素酶菌株XWS-1,生理生化和分子生物学鉴定结果表明该菌株属于枯草芽孢杆菌（Bacillus subtilis）。在含1%CMC-Na液体培养基中,对该菌株的产酶性能进行研究。结果表明:最佳产酶条件为温度35℃,培养基初始pH5.5,培养时间72 h;进一步对其酶学性质进行研究,结果表明:粗酶液最适反应温度是40℃,最适反应pH为5.5。综上所述,XWS-1所产的纤维素酶为中温酸性纤维素酶,较适合用于酒糟等酸性纤维素原料的降解,从而为进一步酒糟纤维素的降解奠定了一定基础,也为重组降解酒糟的纤维素复合酶提供了基因材料。 

Study on screening of high-yield cellulase strains in the fermented grains and its enzymatic properties

Cellulase has broad application prospects, and has respective characteristics according to the different sources. The cellulase microbes were screened from Luzhou-flavor fermented grains, and further plan to use for the degradation and utilization of cellulose in distiller's grains. Sodium carboxymethyl cellulose culture medium containing Congo red was used to screen for producing enzyme strains, a highly cellulose-secreted strain XWS-1 was obtained. The strain was identified as Bacillus subtilis.The optimum conditions in 1% CMC-Na medium were as follows: 35 ℃, initial pH5.5, cultivate 72 h. The enzymatic activity properties of XWS-1 strains was further studied.The results showed that the optimum reaction temperature of crude enzyme fluid was 40 ℃, and the optimum reaction pH was 5.5. In summary, the cellulase produced by XWS-1 is a medium-temperature and acidic cellulase, which is suitable for the degradation of acidic cellulosesuch as distiller's grains.This work not only provide a foundation for degradation of cellulose in distiller's grains, but also provide a genetic material for recombinant complex cellulasethatcan using degradation of cellulose in distiller's grains.