From simple and specific zymographic detections to the annotation of a fungus Daldinia caldariorum D263 that encodes a wide range of highly bioactive cellulolytic enzymes

Biotechnology for Biofuels

Hsion-Wen Kuo¹  Su-May Yu²  Mu-Rong Kao³  Tuan-Hua David Ho³  Meng-Chun Lin³  Wen-Dar Lin³  Kuo-Sheng Hung³  Chen-Wei Li³  Sheng-Chih Yang⁴ 

[1] Department of Environmental Science and Engineering, Tunghai University;Institute of Molecular Biology, Academia Sinica;Institute of Plant and Microbial Biology, Academia Sinica;Institute of Tropical Plant Science, National Cheng Kung University;

关键词: Zymography;    Genomic annotation;    Biomass degradation;    Cellulolytic enzymes;   

DOI  :  10.1186/s13068-021-01959-1

来源: DOAJ

【 摘 要 】

Abstract Background Lignocellulolytic enzymes are essential for agricultural waste disposal and production of renewable bioenergy. Many commercialized cellulase mixtures have been developed, mostly from saprophytic or endophytic fungal species. The cost of complete cellulose digestion is considerable because a wide range of cellulolytic enzymes is needed. However, most fungi can only produce limited range of highly bioactive cellulolytic enzymes. We aimed to investigate a simple yet specific method for discovering unique enzymes so that fungal species producing a diverse group of cellulolytic enzymes can be identified. Results The culture medium of an endophytic fungus, Daldinia caldariorum D263, contained a complete set of cellulolytic enzymes capable of effectively digesting cellulose residues into glucose. By taking advantage of the unique product inhibition property of β-glucosidases, we have established an improved zymography method that can easily distinguish β-glucosidase and exoglucanase activity. Our zymography method revealed that D263 can secrete a wide range of highly bioactive cellulases. Analyzing the assembled genome of D263, we found over 100 potential genes for cellulolytic enzymes that are distinct from those of the commercially used fungal species Trichoderma reesei and Aspergillus niger. We further identified several of these cellulolytic enzymes by mass spectrometry. Conclusions The genome of Daldinia caldariorum D263 has been sequenced and annotated taking advantage of a simple yet specific zymography method followed by mass spectrometry analysis, and it appears to encode and secrete a wide range of bioactive cellulolytic enzymes. The genome and cellulolytic enzyme secretion of this unique endophytic fungus should be of value for identifying active cellulolytic enzymes that can facilitate conversion of agricultural wastes to fermentable sugars for the industrial production of biofuels.

【 授权许可】

Unknown