文献类型：期刊文献

英文题名：Enhancement of cellulase production in Trichoderma reesei RUT-C30 by comparative genomic screening

作者：Liu, Pei[1];Lin, Aibo[1];Zhang, Guoxiu[1];Zhang, Jiajia[1];Chen, Yumeng[1];Shen, Tao[2];Zhao, Jian[1];Wei, Dongzhi[1];Wang, Wei[1]

机构：[1]East China Univ Sci & Technol, State Key Lab Bioreactor Engn, POB 311,130 Meilong Rd, Shanghai 200237, Peoples R China;[2]Sunson Ind Grp Co Ltd, Beijing, Peoples R China

年份：2019

卷号：18

外文期刊名：MICROBIAL CELL FACTORIES

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000467651200001)】；

基金：This research was supported by the Open Funding Project of the State Key Laboratory of Bioreactor Engineering.

语种：英文

外文关键词：Trichoderma reesei; RUT-C30; Genome sequencing; Cellulase production; tre108642; tre56839; Alcohol dehydrogenase; CRE1

摘要：BackgroundCellulolytic enzymes produced by the filamentous fungus Trichoderma reesei are commonly used in biomass conversion. The high cost of cellulase is still a significant challenge to commercial biofuel production. Improving cellulase production in T. reesei for application in the cellulosic biorefinery setting is an urgent priority.ResultsTrichoderma reesei hyper-cellulolytic mutant SS-II derived from the T. reesei NG14 strain exhibited faster growth rate and more efficient lignocellulosic biomass degradation than those of RUT-C30, another hyper-cellulolytic strain derived from NG14. To identify any genetic changes that occurred in SS-II, we sequenced its genome using Illumina MiSeq. In total, 184 single nucleotide polymorphisms and 40 insertions and deletions were identified. SS-II sequencing revealed 107 novel mutations and a full-length wild-type carbon catabolite repressor 1 gene (cre1). To combine the mutations of RUT-C30 and SS-II, the sequence of one confirmed beneficial mutation in RUT-C30, cre1(96), was introduced in SS-II to replace full-length cre1, forming the mutant SS-II-cre1(96). The total cellulase production of SS-II-cre1(96) was decreased owing to the limited growth of SS-II-cre1(96). In contrast, 57 genes mutated only in SS-II were selected and knocked out in RUT-C30. Of these, 31 were involved in T. reesei growth or cellulase production. Cellulase activity was significantly increased in five deletion strains compared with that in two starter strains, RUT-C30 and SS-II. Cellulase production of T. reesei 108642 and 56839 was significantly increased by 83.7% and 70.1%, respectively, compared with that of RUT-C30. The amount of glucose released from pretreated corn stover hydrolyzed by the crude enzyme from 108642 increased by 11.9%.ConclusionsThe positive attribute confirmed in one cellulase hyper-producing strain does not always work efficiently in another cellulase hyper-producing strain, owing to the differences in genetic background. Genome re-sequencing revealed novel mutations that might affect cellulase production and other pathways indirectly related to cellulase formation. Our strategy of combining the mutations of two strains successfully identified a number of interesting phenotypes associated with cellulase production. These findings will contribute to the creation of a gene library that can be used to investigate the involvement of various genes in the regulation of cellulase production.