Optimization of the production of trichoderma reesei endoglucanase I in pichia pastoris

Abstract

The aim of this study is to produce Trichoderma reesei endoglucanase I in Pichia pastoris. Pichia pastoris is the host of the production since it has many advantages like high level production of foreign proteins and possession of a tightly regulated promoter, alcohol oxidase I. Pichia cells expressing heterologous endoglucanase I was grown in fermenter with different strategies. The effects of temperature and methanol concentration on EG I production were tried to be understood. Especially the effect of methanol level in fermenter was investigated since the induction of the promoter needs methanol. Batch and fed-batch fermentations were performed and analyses of the samples were done. Sorbitol was used as a co-substrate to methanol to keep cells growing during production. Protein concentrations, activity analysis of EG I, SDS-PAGE and growth rate results were compared and high level production of endoglucanase I in Pichia pastoris was tried to be optimized. For the production of EG I in Pichia pastoris, less methanol level and low fermentation temperature were found to be best conditions. Results obtained in this study can be used for further studies and applications especially in detergent, pulp and paper industry.