高产碱性纤维素酶丝状真菌筛选及产酶研究

Isolation,identification and enzymology properties research of a high-yield alkaline cellulase filamentous fungi

采取广西凭祥市原始森林土样为原料,以羧甲基纤维素钠(CMC-Na)为唯一碳源,分离纯化后用刚果红染色法进行初筛,得到两株产纤维素酶能力较强的菌株(PX-10与PX-14)。PX-14有相对较强的产纤维素酶能力,其葡聚糖内切酶活达到5.3 U/mL、滤纸酶活达到5.9 U/mL,根据PX-14菌株形态特征和分子鉴定,鉴定为产黄青霉。对其所产的葡聚糖内切酶的酶学性质进行研究,结果显示,PX-14的葡聚糖内切酶最适温度为50℃,在40～50℃有较高的温度稳定性;最适pH值为8.9,在pH值为8～10之间有较高的pH值稳定性;Co^(2+)、Cu^(2+)对该酶有促进作用,Zn^(2+)、Fe^(2+)等对该酶有抑制作用。该菌具有较强的蔗渣降解能力。

The original forest soil samples from Pingxiang City, Guangxi were used as raw materials, and sodium carboxymethyl cellulose(CMC-Na) was used as the sole carbon source. After separation and purification, the Congo red staining method was used for preliminary screening to obtain two cellulase-producing enzymes,i.e. the more capable strains PX-10 and PX-14. PX-14 has relatively strong cellulase-producing ability, the CMC enzyme activity reaches 5.3 U/mL,and the filter paper activity reaches 5.9 U/mL. The morological characteristics and molecular identification of the strain were identified as Penicillium chrysogenum. The enzymatic properties of the CMC enzyme produced by the study showed that the optimum temperature of the CMC enzyme of PX-14 was 50 ℃, and the temperature stability was higher at 40~50 ℃;the optimum pH was 8.9. It had high pH stability between pH 8~10;Co^2+ and Cu^2+ promoted the enzyme, and Zn^2+ and Fe2+inhibited the enzyme. The bacterium has a strong ability to degrade bagasse.