高产纤维素酶的木霉菌株筛选及发酵条件优化  

Screening high cellulase production Trichoderma strains and optimization of fermentation conditions

作　　者：周礼 庄文颖[1] ZHOU Li;ZHUANG Wenying(State Key Laboratory of Mycology,Institute of Microbiology,Chinese Academy of Sciences,Beijing 100101,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院微生物研究所真菌学国家重点实验室,北京100101 [2]中国科学院大学,北京100049

出　　处：《菌物学报》2023年第9期1966-1980,共15页Mycosystema

基　　金：国家自然科学基金(31570018,31750001)。

摘　　要：纤维素是由β-1,4糖苷键链接而成的葡萄糖单体聚合物,广泛分布于自然界,是一类易获取且廉价的可再生资源。自然界含纤维素材料的利用和处理是目前亟待解决的问题,筛选产纤维素酶的优良菌株并实现纤维素的有效利用具有重要意义。利用纤维素酶降解纤维素是绿色、高效和可持续的利用方式,广泛应用于工业和农业领域(养殖、能源、纺织等)。因此,实现高效低成本的纤维素酶生产成为研究和发展的目标。木霉属真菌是重要的纤维素酶产生菌,具有产酶量大、酶系全和酶活性高等优点,分泌的胞外酶易于工业生产中的分离提纯。本研究以课题组前期积累和保存的25种木霉150个菌株为材料,通过刚果红平板法筛选、滤纸酶活测定和天然纤维素降解等测试,筛选出14株产纤维素酶能力较强的菌株(优于对照菌株里氏木霉QM9414),从中选取3株进行最佳产酶条件探索,如接种量、吐温80添加量、发酵培养基pH值等。初步测试结果表明,贵州木霉菌株8705在20℃条件下、摇瓶发酵9 d、在优化后的发酵培养基中产酶效果最佳,其上清液酶活可达到6.63 IU/mL。通过优化发酵温度、发酵时间和培养基成分配比等发酵条件,为资源利用打下物质基础并提供理论依据。Cellulose is a polymer of glucose monomers linked byβ-1,4 glycosidic bonds.It is widely distributed in nature,which is an easy-to-obtain and inexpensive renewable resource.The treatment and utilization of natural cellulose is an urgent problem to be solved.Therefore,screening excellent cellulase-producing strains and enabling effective utilization of cellulose is an important task.Nowadays cellulase is widely used in industrial and agricultural fields like stockbreeding,energy,textile,etc.Therefore,selection of high-efficiency and low-cost cellulase production fungal strains becomes the goal of this research.Trichoderma species are one of the groups of high-level cellulase producing fungi,which have the advantages of rich enzyme production,complete enzyme system,and high enzyme activity.Their extracellular enzymes are easy to separate and purify.In this study,150 Trichoderma strains belonging to 25 species obtained in our previous research were used as the materials.Among them,14 strains appeared to possess relatively high cellulase-producing ability as screened by the Congo red plate method,filter paper enzyme activity assay,and natural cellulose degradation tests.Three of them were further explored to optimal conditions for enzyme production,such as inoculation amount of spore suspension,required amount of Tween 80,and pH of fermentation,etc.Our results showed that Trichoderma guizhouense strain 8705 expressed the best enzyme production ability,and its supernatant enzyme activity reached 6.63 IU/mL when fermented in shake flasks in the optimized fermentation medium at 20°C for 9 days.This indicates that temperature,time and medium significantly influence the fermentation efficacy of the Trichoderma strain.

关 键 词：木霉 纤维素酶 酶活测定 发酵条件优化 

分 类 号：TQ920.6[轻工技术与工程—发酵工程]