高产纤维素酶菌株的筛选

该研究从农田土壤中分离得到67株细菌,并从中选出一株高产纤维素酶菌株。将这些菌株接种到纤维素培养基上,在p H 5.5和28℃的条件下,利用刚果红染色溶液进行染色后,测其水解透明圈与菌落的比值的大小,进行初步筛选。将这些初筛的菌株接种到培养基中进行摇床培养后,制得粗酶液,并分析羧甲基纤维素酶(CMC)活力测定和滤纸酶(FP)活力及β-葡萄糖苷酶(BG)。在不同温度的条件下,对纤维素酶活力测定,最终筛选出曲霉A25(Aspergillus sp.)这一株菌株,最适酶活温度为50℃。产纤维素酶酶活力分别为:CMC酶活达2 340.92 U/m L;FP酶活达2.66U/m L;BG酶活达164.72U/m L。

Screening of Strains for High-yielding Cellulase

67 strains of soil bacteria were isolated form farmland,from which a high-yielding cellulase strain was screened.These strains were inoculated on the cellulose medium,and a preliminary screening was conducted,in which we measured hydrolysis transparent circle and the ratio of the size of the colony under pH5.5 and 28℃condi?tions by using the Congo Red staining.Furthermore,these selected strains were cultured,and a crude enzyme liquid was extracted for analyzing the activities of carboxymethyl cellulose(CMC),filter paper enzyme(FP)andβ-glucosi?dase(BG).Under different temperature conditions,the activity of cellulase was determined,and ultimately this one strain of Aspergillus A25 was obtained.Its great activity is under the condition of optimum temperature for 50℃.Pro?ducing cellulose enzyme activity was as following:CMC amounted to 2 340.92 U/mL,FP activity amounted to 2.66 U/mL,and BG activity amounted to 164.72 U/mL.