Abstract
In the search for suitable cellulase combinations for industrial biofinishing of cotton, five different types of Trichoderma reesei
strains were constructed for elevated cellobiohydrolase production:
CBHI overproducers with and without endoglucanase I (EGI), CBHII
overproducers with and without endoglucanase II (EGII) and strains
overproducing both CBHI and CBHII without the major endoglucanases I and
II. One additional copy of cbh1 gene increased production of
CBHI protein 1.3-fold, and two copies 1.5-fold according to ELISA
(enzyme-linked immunosorbent assay). The level of total secreted
proteins was increased in CBHI transformants as compared to the host
strain. One copy of the cbh2 expression cassette in which the cbh2 was expressed from the cbh1 promoter increased production of CBHII protein three- to four-fold when compared to the host strain. T. reesei strains producing elevated amounts of both CBHI and CBHII without EGI and EGII were constructed by replacing the egl1 locus with the coding region of the cbh1 gene and the egl2 locus with the coding region of cbh2. The cbh1 was expressed from its own promoter and the cbh2 gene using either the cbh1 or cbh2
promoter. Production of CBHI by the CBH-transformants was increased up
to 1.6-fold and production of CBHII up to 3.4-fold as compared with the
host strain. Approximately similar amounts of CBHII protein were
produced by using cbh1 or cbh2 promoters. When the
enzyme preparation with elevated CBHII content was used in biofinishing
of cotton, better depilling and visual appearance were achieved than
with the wild type preparation; however, the improvement was not as
pronounced as with preparations with elevated levels of endoglucanases
(EG).
Original language | English |
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Pages (from-to) | 305 - 317 |
Number of pages | 13 |
Journal | Journal of Biotechnology |
Volume | 116 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2005 |
MoE publication type | A1 Journal article-refereed |
Keywords
- Cellobiohydrolase
- T. reesei
- Overproduction
- Biofinishing