Introduction

The cellulase research laboratory of the Shanghai Institute of Plant Physiology has been interested in cellulose conversion by enzymes from Trichoderma pseudokoningii，particularly the isolation and characterization of hyper producing cellulase mutants，for several years.Several papers on this work have been published in Chinese.［1-9］This review summarizes these papers in English.

Cellulose，which is a photosynthetic product and a renewable energy resource，occurs in nature in vast quantity as an agricultural，industrial and urban waste.The annual production of rice straw，wheat stem，corn cob and shells of cotton seed in China alone has been estimated to be 4×108 tons.Therefore，cellulose is a very important potential food and energy resource.Several approaches have been made to increase cellulase production in our laboratory.The first was to find the hypercellulolytic Trichoderma strains by screening of wild types and selection of further induced mutants.The second was to investigate the induction and regulatory mechanism of cellulase synthesis in Trichoderma.This knowledge is the basis of increasing cellulase production by a change of culture conditions as well as by genetic manipulations.This paper presents results obtained from the study of cellulase induction and regulation using two Trichoderma mutants.The approaches include ①cellulase induction by sophorose，②　catabolite repression，③inductive effect of glucose molasses，④ changes in the regulatory mechanisms of cellulase synthesis in two mutants，⑤ separation，purification and characterization of cellulase induced by sophorose and ⑥ isolation of a PolyA-RNA induced by sophorose in washed mycelium of Trichoderma.(https://www.daowen.com)