果胶裂解酶产生真菌的选育及酶学性质研究  

Breeding and Enzymatic Properties of Fungi Produce Pectin Lyase

作　　者：周力[1] 陈华萍[1] 李哲[1] 黄乾明[1] 

机构地区：[1]四川农业大学理学院,雅安625014

出　　处：《基因组学与应用生物学》2016年第11期3076-3082,共7页Genomics and Applied Biology

基　　金：四川省教育厅重点科研项目(No.08ZA053);四川农业大学科技创新基金项目(No.00731200)共同资助

摘　　要：果胶裂解酶(pectin lyase)具有降解果胶物质的能力,在工业、医药等领域有着重要作用,目前主要由果胶裂解酶功能菌株进行工业发酵生产,但现已开发的能用于工业生产的菌株资源十分有限。本实验采用刚果红染色法从雅安果园富含果胶土壤中筛选果胶裂解酶产生菌株,旨在为果胶裂解酶工业生产开发新的菌株资源。实验最终筛选出一株果胶裂解酶产生真菌菌株,经形态学和分子生物学鉴定为丛梗孢目曲霉属(Aspergillus monilia)的黄曲霉(Aspergillus flavus)。发酵条件研究表明,其最佳培养基的组成为(g/L):桔皮粉3,麸皮5,K_2HPO_4 0.05,Mg SO40.05,在此组合下酶活可达1.48 U/m L;最适培养条件为:初始p H 8.0,接种量8%,温度30℃,摇床转速200 r/min,培养时间48 h。酶学性质研究表明:该酶的最适p H为8.0,在p H 7.0~9.0范围内稳定性良好;最适温度为50℃,在40~50℃范围内稳定性较好;Ca^(2+)、Mg^(2+)对酶有较明显的激活作用,Mn^(2+)、Cu^(2+)、Zn^(2+)等对酶有不同程度的抑制作用。本研究成功对筛选菌株进行了发酵条件优化、酶学性质的研究,为果胶裂解酶工业生产菌株的选育以及实际应用提供实验依据。Pectin lyase has the ability of degrading pectic, and plays an important role in industry, medicine industry, etc, which is mainly produced by industrial fermentation of pectin lyase functional strain, but the strains that has been developed to be used for industrial production of strain resources is limited. This study adopted the Congo red staining method to screen out pectin lyase functional strain from Ya＇an orchard soil that was rich in pectin. It aimed to develop new strains resources for pectin lyase industrial production. The study finally got a fungi strain which could produce pectin lyase, whose morphological and molecular biology identification is Aspergillus flavus ofAspergillus monilia. Studies showed that fermentation conditions, the optimum composition of medium was （g/L）： orange peel powder 3, wheat bran 5, K2HPO4 0.05, MgSO4 0.05. In this combination, the enzyme activity reached to 1.48 U/mL; The optimum culture conditions was that： initial pH was 8.0, inoculum size was 8%, the temperature was 30~C, table rotate speed was 200 r/min, incubation time was 48 h. The study of enzymatic properties of pectin lyase produced by the strains showed that its optimal pH was 8.0, and it had a good stability within the scope of pH 7.0-9.0; Besides, the optimal temperature of this enzyme was 50 ℃, it had a good stability within the scope of temperature 40-50℃ ; Ca^2＋ and Mg^2＋ had a obvious activation on the enzyme, while Mn^2＋, Cu^2＋ and Zn^2＋ had a inhibition with different degree on it. In this study, we successfully carried out the optimization of fermentation conditions and the study on enzymatic properties of the strains screening, which provided the experimental basis for selection, breeding and practical application of industrial production strain on pectin lyase.

关 键 词：果胶裂解酶 黄曲霉 酶学性质 发酵条件 

分 类 号：Q939.9[生物学—微生物学]