Anli Geng
BioEnergy Society of Singapore, Singapore
Title: Hyper cellulase-producing fungus Talaromyces pinophilus EMM development through random mutagenesis and genetic engineering
Biography
Biography: Anli Geng
Abstract
Talaromyces pinophilus UTA1 and EMM are cellulase hyper-producing mutants that originated from T. pinophilus OPC4-1 through UV irradiation and chemical mutagenesis by NTG and EMS. Full genome sequencing of these two mutants and the parent strain was conducted and 73 genes were identified with either SNPs or InDels. Functions of the 73 genes were identified using NCBI GenBank database. Among the 73 genes, 3 transcription factors were identified. They might be responsible for the enhancement of cellulase activity in mutant strains, UTA1 and EMM. Genes encoding the 3 transcription factors were successfully cloned to further confirm their enhancement in cellulase and hemicellulase production in mutant strains. Further genetic engineering of the mutant strain EMM was conducted to further enhance its enzyme production. A uracil auxotroph strain T. pinophilus EMU was isolated through random mutagenesis. A wild-type pyrF gene encoding orotate phosphoribosyl transferase (OPRTase, EC 2.4.2.10) isolated from T. pinophilus OPC4-1, the parent strain can be used as the selection marker for genetic engineering of strain T. pinophilus EMM. A marker recycle system was developed and was used for the knock-out of creA gene, the gene mediating catabolite repression. A creA gene knock-out strain, A creA 21 was successfully isolated. It demonstrated enhanced cellulase and xylanase production and higher resistance to the increased glucose concentration. The genetic engineering tools were successfully developed for strain T. pinophilus EMM and disruption of creA gene in strain EMM was effective for enhanced enzyme production.