The Hemicellulase Activity Change Of Piptoporus Betulinus And Its Transcriptome Induced By Birch Sawdust

The activity of three major hemicellulases produced by Piptoporus betulinus in seven different culture media were measured. The enzymatic properties were also partly screened. To investigate the number and structure of lignocellulose-degrading genes in P. Betulinus, and their different regulation ways in wood-degradating process, we induced fungi using different carbon source for 20 days (birch sawdust induced for YLX-B and none for YLX-A), and then analyzed and sequenced the transcriptome of fungi, in order to lay a foundation for study the molecular mechanism of lignocellulose degradation.To research the activity changes of three hemicellulases, seven different carbon sources were used in different culture media, including sawdust from spruce, mongolian pine, birch, com stover, grass meal of L chinensis, wheat bran and corn flour. The results showed that corn flour and wheat bran had the highest induced function for xylanase, the effect s of grass meal and corn stover are better than the others for mannase. Straw induced higher a-glycosidase enzyme activity than the medium with woody lignocellulose. The optimum reaction temperature for three hemicellulase were all 50℃, and the optimum pH values were 5.0,6.0, and 7.0 for xylanase, mannose and a-glycosidase, respectively.To research the molecular mechanism of lignocellulose degradation, the transcriptome were sequenced using Solexa method for differentlly cultured P. betulinus (induced by birch sawdust for YLX-B and none for YLX-A). The results wre as follows:21882 genes were obtained. Among them,21255 genes matched with Nr database, and 6256 involved in 309 different known metabolism and signaling pathways.7955 genes annotated in COG database with 24 different functions.3351 unigenes could be found in GO database. Two samples had significant differences in gene expression. There were 776 differentially expressed genes, which 444 genes up-regulated in YLX-B and 332 down-regulated, compairing to YLX-A. The founding demonstrated that the expression of lignocellulose degrading-related genes will significantly change with different carbon source, suggesting that these genes could be induced.