63 research outputs found
L-lactic acid production from D-xylose with Candida sonorensis expressing a heterologous lactate dehydrogenase encoding gene
A truncated form of the Carbon catabolite repressor 1 increases cellulase production in Trichoderma reesei
Expression of Trichoderma reesei cellulases CBHI and EGI in Ashbya gossypii
To explore the potential of Ashbya gossypii as a
host for the expression of recombinant proteins and to
assess whether protein secretion would be more similar to
the closely related Saccharomyces cerevisiae or to other
filamentous fungi, endoglucanase I (EGI) and cellobiohydrolase
I (CBHI) from the fungus Trichoderma reesei were
successfully expressed in A. gossypii from plasmids
containing the two micron sequences from S. cerevisiae,
under the S. cerevisiae PGK1 promoter. The native signal
sequences of EGI and CBHI were able to direct the
secretion of EGI and CBHI into the culture medium in A.
gossypii. Although CBHI activity was not detected using 4-
methylumbelliferyl-ÎČ-D-lactoside as substrate, the protein
was detected by Western blot using monoclonal antibodies.
EGI activity was detectable, the specific activity being
comparable to that produced by a similar EGI producing S.
cerevisiae construct. More EGI was secreted than CBHI, or
more active protein was produced. Partial characterization
of CBHI and EGI expressed in A. gossypii revealed
overglycosylation when compared with the native T. reesei
proteins, but the glycosylation was less extensive than on
cellulases expressed in S. cerevisiae.Fundação para a CiĂȘncia e a Tecnologia (FCT
Evidence of cAMP involvement in cellobiohydrolase expression and secretion by Trichoderma reesei in presence of the inducer sophorose
Simulated Atmospheric N Deposition Alters Fungal Community Composition and Suppresses Ligninolytic Gene Expression in a Northern Hardwood Forest
High levels of atmospheric nitrogen (N) deposition may result in greater terrestrial carbon (C) storage. In a northern hardwood ecosystem, exposure to over a decade of simulated N deposition increased C storage in soil by slowing litter decay rates, rather than increasing detrital inputs. To understand the mechanisms underlying this response, we focused on the saprotrophic fungal community residing in the forest floor and employed molecular genetic approaches to determine if the slower decomposition rates resulted from down-regulation of the transcription of key lignocellulolytic genes, by a change in fungal community composition, or by a combination of the two mechanisms. Our results indicate that across four Acer-dominated forest stands spanning a 500-km transect, community-scale expression of the cellulolytic gene cbhI under elevated N deposition did not differ significantly from that under ambient levels of N deposition. In contrast, expression of the ligninolytic gene lcc was significantly down-regulated by a factor of 2â4 fold relative to its expression under ambient N deposition. Fungal community composition was examined at the most southerly of the four sites, in which consistently lower levels of cbhI and lcc gene expression were observed over a two-year period. We recovered 19 basidiomycete and 28 ascomycete rDNA 28S operational taxonomic units; Athelia, Sistotrema, Ceratobasidium and Ceratosebacina taxa dominated the basidiomycete assemblage, and Leotiomycetes dominated the ascomycetes. Simulated N deposition increased the proportion of basidiomycete sequences recovered from forest floor, whereas the proportion of ascomycetes in the community was significantly lower under elevated N deposition. Our results suggest that chronic atmospheric N deposition may lower decomposition rates through a combination of reduced expression of ligninolytic genes such as lcc, and compositional changes in the fungal community
Enzymatic process optimization for the in vitro production of isoprene from mevalonate
Engineering towards a complete heterologous cellulase secretome in Yarrowia lipolytica reveals its potential for consolidated bioprocessing
Kinetic transcriptome analysis reveals an essentially intact induction system in a cellulase hyper-producer Trichoderma reesei strain
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