摘要
引言里氏木霉（Trichoderma reesei）是目前常用的纤维素酶生产菌种,其分泌的纤维素酶是一个多组分的复合体系,主要包括5种内切型-β-葡聚糖酶（endo-β-glucanase,EG,EC3.2.1.4）,
Cellobiase（CB）is an important component in the cellulase system.At present,the cellulase preparation produced by Trichoderma reesei is poor in cellobiase and restricts the conversion of cellobiose to glucose.In this study,the CB gene of 2526bp from Aspergillus niger was cloned by the reverse transcription PCR method,and was inserted between the strong promoter Pcbh1（including secreting signal peptide sequence）and the terminator Tcbh1 from T.reesei to construct a recombinant plasmid pHB9 including the hygromycin B resistance marker.The plasmid pHB9 was transformed into the conidia of T.reesei by using the PEG-CaCl2 method to obtain 387 positive transformants.Ten fast growth transformants were isolated by the rescreening culture plates using cellobiose as sole carbon source.It was confirmed that the CB gene from A.niger was integrated into the chromosomal DNA of T.reesei by the PCR test.Cellulase production by the recombinant transformants was performed in shaking flasks,and five high CB activity transformants were obtained.After 48h fermentation,the CB activity in culture broth could reach 5.3 IU·ml-1,which was 106 times that of the host strain.It demonstrated that CB gene from A.niger was efficiently expressed and the enzyme was successfully secreted.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2011年第2期452-457,共6页
CIESC Journal
基金
国家高技术研究发展计划项目(2007AA05Z401)
国家科技支撑计划项目(2007BAD66B02)
浙江省自然科学基金重大资助项目(Z407010)~~
关键词
纤维二糖酶
黑曲霉
里氏木霉
纤维素酶
胞外分泌
cellobiase
Aspergillus niger
Trichoderma reesei
cellulase
extracellular secretion
