一株产纤维素酶放线菌的分离鉴定及酶学性质研究  

Isolation, Identification and Enzymatic Properties of a Cellulose-producing Actinomyces

作　　者：任大明[1] 赵钰[1] 白炜琪 陈红漫[1] 阚国仕[1] 佡思涵 张聪[1] 

机构地区：[1]沈阳农业大学生物科学技术学院,沈阳110161

出　　处：《沈阳农业大学学报》2016年第6期667-672,共6页Journal of Shenyang Agricultural University

基　　金：沈阳市科技攻关项目(F13-141-3-00)

摘　　要：为探究产纤维素酶放线菌的生物学特征及其酶学性质,从土壤中筛选产纤维素酶放线菌,试验采用平板稀释法并结合刚果红染色法对土壤中的纤维素分解菌进行初筛,通过酶活测定复筛,筛得产纤维素酶能力较高的放线菌一株,对该菌株进行形态学、分子生物学及生理生化鉴定,并对酶学性质进行研究。结果表明:该菌在液体发酵中的内切酶、外切酶、β-葡萄糖苷酶及滤纸酶活分别为30.06,10.40,8.05和13.88U·m L^(-1);通过对该菌株基因组中编码16S r RNA的DNA序列测序,得到一段1401bp的碱基序列,通过进化树分析可确认该菌为链霉菌属;在酶学性质研究中,该菌所产内切酶、外切酶、β-葡萄糖苷酶及滤纸酶的最适pH值为4.5,外切酶、β-葡萄糖苷酶及滤纸酶的最适反应温度均为50℃,内切酶的最适反应温度为55℃;金属离子Mg^(2+),Ca^(2+),Mn^(2+)对纤维素酶均有激活作用,其中内切酶在pH值4.0~6.5间及在30~60℃的反应温度下,其相对酶活能在70%以上。试验获得的放线菌所产内切酶的酶活和酶适应性较好,为酸性纤维素酶,可为进一步研究放线菌纤维素酶及其生产利用提供理论依据。To study biology characteristics and enzymology properties of cellulose-producing Actinomycetes, screening of cellulose- producing Actinomycetes from the soil. The cellulose produced by Actinomyces generally has better characteristics of alkali resistance and heat resistance, it is easy to modify and analyse gene, Actinomycetes exist widely in nature, and the value of it is very high in its production and development. The cellulose-producing strain was screened from the soil by plate dilution method, Congo red staining method and enzymatic analysis. The strain was identified by morphology, molecular biology, physiological and biochemical analysis, and the enzymatic properties of the strain was studied. The results showed that the enzyme activities of en d o - ^6-glucanase, exo-6-glucanase, β-glucanase and FPase in the liquid fermentation were 30.06 U·mL-1, 10.40 U·mL-1, 8.05 U·mL-1 and 13.88 U·mL-1,respectively. The 1401bp base sequence was obtained by 16S rDNA sequencing, and the phylogenetic tree analysis of the sequence can identify that the strain is Streptomyces. In the study of enzymatic properties, the optimum pH of endo-6-glucanase, exo-6-glucanase, ^6-glucanase and FPase is pH 4.5, the optimum reaction temperature of exo-6-glucanase,茁- glucanase and FPase is 50益, and the en d o -6 -g lu c an a s is 55益,the Mg2＋,Ca2＋,Mn2＋ have active effect on cellulase. The e n d o -6 - glucanas under the environment of pH 4.0 -6.5 and 30-60益, the relative enzyme activity was over 7 0%. In this study, the cellulose is acidic. And we also found that the enzymatic activity and adaptability of endo -6 -glucanas was better. This study could provide a theoretical basis for further study of Actinomycetes cellulase and utilization.

关 键 词：纤维素酶 放线菌 筛选鉴定 酶学性质 

分 类 号：Q556.2[生物学—生物化学]