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ISSN
1672-9145
Acta Biochim Biophys Sin
2004, 36(10): 667–672
CN 31-1940/Q
Novel Cellulase Profile of Trichoderma reesei Strains
Constructed by cbh1 Gene Replacement with eg3 Gene Expression Cassette
Tian-Hong WANG*, Ti
LIU, Zhi-Hong WU, Shi-Li LIU, Yi LU, and Yin-Bo QU
The State Key
Laboratory of Microbial Technology, Shandong University, Jinan 250100, China
Abstract To construct strains of
the filamentous fungus Trichoderma reesei with low cellobiohydrolases
while high endoglucanase activity, the Pcbh1-eg3-Tcbh1 cassette was constructed and the coding sequence of the
cellobiohydrolase I (CBHI) gene was replaced with the coding sequence of the eg3
gene by homologous recombination. Disruption of the cbh1 gene was
confirmed by PCR, Southern dot blot and Western hybri-dization analysis in two
transforments denoted as L13 and L29. The filter paper-hydrolyzing activity of
strain L29 was 60% of the parent strain Rut C30, and the CMCase activity was
increased by 33%. This relatively modest increase suggested that the eg3
cDNA under the control of the cbh1 promoter was not efficiently
transcribed as the wild type cbhl gene. However our results confirmed
that homologous recombination could be used to construct strains of the
filamentous fungus Trichoderma reesei with novel cellulase profile. Such
strains are of interest from the basic science perspective and also have
potential industrial applications.
Key words Trichoderma reesei;
gene replacement; gene disruption; cbh1; eg3
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Received: June 14, 2004 Accepted: August 14,
2004
This work was supported by the grants from the National Natural
Science Foundation of China (No. 30070014), the Natural Science Foundation of
Shandong Province (No. Y2000D12) and the Major State Basic Research Development
Program of China (No. 2003CB716006)
*Corresponding author: Tel, 86-531-8364384-8109; Fax, 86-531-8565234; E-mail,
[email protected]