Distinct lignocellulolytic enzymes produced by Trichoderma harzianum in response to different pretreated substrates

In order to optimize the composition of enzyme cocktail for improving the hydrolytic efficiency of lignocellulose, different substrates were tested as inducers for producing lignocellulolytic enzymes by Trichoderma harzianum EM0925 in this study. As results, ultrafine grinding or steam explosion pretreated substrates can induce T. harzianum EM0925 to secret holo lignocellulolytic enzymes; acid treated substrate can induce cellobiohy-drolase; while alkali or sodium chlorite treated substrates can induce beta-xylosidase specifically. Furthermore, the combination of enzyme cocktails with different hydrolysis characteristics can further improve the hydrolysis efficiency, since 100% yields of glucose and xylose were obtained simultaneously from ultrafine grinding treated corn stover at low enzyme dosage (1.2 mg proteins/g substrate). This study for the first time demonstrated an effective solution that specific-pretreated substrates can be used as inducers for specific enzyme production by T. harzianum, which provided new idea and potential strategy for the construction of highly-efficient ligno-cellulolytic enzyme cocktails.

Automated summary

This study investigated the use of different substrates as inducers to optimize the composition of enzyme cocktails for improving the hydrolytic efficiency of lignocellulose. It was found that ultrafine grinding or steam explosion pretreated substrates could induce T. harzianum EM0925 to produce complete lignocellulolytic enzymes, acid treated substrates could induce cellobiohydrolase production, and alkali or sodium chlorite treated substrates could induce beta-xylosidase production specifically. The combination of enzyme cocktails with different hydrolysis characteristics further improved the hydrolysis efficiency. This study provides a new and effective solution for the construction of highly-efficient lignocellulolytic enzyme cocktails.