产纤维素酶菌株的筛选、鉴定及产酶特性的研究

Study on Screening,Identification and Enzyme Production Characteristics of Cellulase-producing Strains

纤维素作为各种植物秸秆的主要组成物质广泛存在于自然界中,纤维素酶是一种催化纤维素降解产生葡萄糖的酶,可通过不同方式减少环境中纤维素的富集。为获得产酶能力高的降解纤维素菌株,利用刚果红平板法,从腐殖土中分离筛选出一株具有高产纤维素酶能力的菌株CTE1-1,经鉴定为芽孢杆菌(Bacillus sp.)。通过培养时间、培养温度、初始pH及NaCl浓度的单因素实验,确定该菌在含1%CMCA-Na的产酶培养基中培养,温度30℃,初始pH 7.0、NaCl浓度1.5%,经108h培养CMCA酶酶活可达42.59 U/mL,经96h培养FPA酶酶活可达45.66U/mL。该菌株所产纤维素酶在pH 6.0、50℃均表现很强的酶活力,Fe^(3+)、K^(+)对该菌所产纤维素酶具有激活能力,Mg^(2+)对该菌所产纤维素酶无影响,Cu^(2+)、Zn^(2+)对其具有一定的抑制能力。该菌株产纤维素酶能力强,可用于纤维素酶制剂的生产。

Cellulose,as a main constituent of various plant straws,widely exists in nature,and cellulase,an enzyme that catalyzes the degradation of cellulose to produce glucose,can be used in different ways to reduce the enrichment of cellulose in the environment.In order to obtain cellulose-degrading strains with high enzyme-producing capacity,a strain with high cellulase-producing capacity,CTE1-1,was isolated and screened from humus using the Congo red plate method and identified as Bacillus sp.Through the one-factor experiments of incubation time,incubation temperature,initial pH and NaCl concentration,it was determined that the bacterium was cultured in enzyme-producing medium containing 1% CMCA-Na at 30℃,initial pH 7.0 and NaCl concentration 1.5%,and the enzyme activity of CMCA enzyme could be up to 42.59 U/mL after 108h incubation,and the enzyme activity of FPA enzyme could be up to 45.66 U/mL after 96h incubation.The cellulase produced by this strain showed strong enzyme activity at pH 6.0 and 50℃,Fe^(3+) and K^(+) had activation ability for the cellulase produced by this strain,Mg^(2+) had no effect on the cellulase produced by this strain,and Cu^(2+) and Zn^(2+) had certain inhibitory ability for it.This strain has a strong ability to produce cellulase and can be used for the production of cellulase preparations.rain has a strong ability to produce cellulase and can be used for the production of cellulase preparations.