Characterization of a novel swollenin from Penicillium oxalicum in facilitating enzymatic saccharification of cellulose

BMC Biotechnology

Research Article

Miao Xing¹  Shaowen Wang¹  Guohong Lai¹  Gang Liu¹  Kang Kang² 

[1]College of Life Science, Shenzhen Key Laboratory of Microbial Genetic Engineering, Shenzhen University, 518060, Shenzhen, China

[2]College of Life Science, Shenzhen Key Laboratory of Microbial Genetic Engineering, Shenzhen University, 518060, Shenzhen, China

[3]College of Animal Science and Technology, Northwest A&F University, 712100, Yangling, Shaanxi, China

关键词: Cellulase;    Cellulose;    Expansin;    Swollenin;    Penicillium oxalicum;    Trichoderma reesei;   

DOI  :  10.1186/1472-6750-13-42

 received in 2013-02-15, accepted in 2013-05-16,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundPlant expansins and fungal swollenin that can disrupt crystalline cellulose have great potential for applications in conversion of biomass. Recent studies have been mainly focused on Trichoderma reesei swollenin that show relatively low activity in the promotion of cellulosic hydrolysis. Our aim was to isolate a novel swollenin with greater disruptive activity, to establish an efficient way of producing recombinant swollenin, and to optimize the procedure using swollenin in facilitation of cellulosic hydrolysis.ResultsA novel gene encoding a swollenin-like protein, POSWOI, was isolated from the filamentous fungus Penicillium oxalicum by Thermal Asymmetric Interlaced PCR (TAIL-PCR). It consisted of a family 1 carbohydrate-binding module (CBM1) followed by a linker connected to a family 45 endoglucanase-like domain. Using the cellobiohydrolase I promoter, recombinant POSWOI was efficiently produced in T. reesei with a yield of 105 mg/L, and showed significant disruptive activity on crystalline cellulose. Simultaneous reaction with both POSWOI and cellulases enhanced the hydrolysis of crystalline cellulose Avicel by approximately 50%. Using a POSWOI-pretreatment procedure, cellulases can produce nearly twice as many reducing sugars as without pretreatment. The mechanism by which POSWOI facilitates the saccharification of cellulose was also studied using a cellulase binding assay.ConclusionWe present a novel fungal swollenin with considerable disruptive activity on crystalline cellulose, and develop a better procedure for using swollenin in facilitating cellulosic hydrolysis. We thus provide a new approach for the effective bioconversion of cellulosic biomass.

【 授权许可】

Unknown   
© Kang et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.