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The effects of disruption of phosphoglucose isomerase gene on carbon utilisation and cellulase production in Trichoderma reesei Rut-C30.
Microb Cell Fact. 2011 May 24; 10:40.MC

Abstract

BACKGROUND

Cellulase and hemicellulase genes in the fungus Trichoderma reesei are repressed by glucose and induced by lactose. Regulation of the cellulase genes is mediated by the repressor CRE1 and the activator XYR1. T. reesei strain Rut-C30 is a hypercellulolytic mutant, obtained from the natural strain QM6a, that has a truncated version of the catabolite repressor gene, cre1. It has been previously shown that bacterial mutants lacking phosphoglucose isomerase (PGI) produce more nucleotide precursors and amino acids. PGI catalyzes the second step of glycolysis, the formation of fructose-6-P from glucose-6-P.

RESULTS

We deleted the gene pgi1, encoding PGI, in the T. reesei strain Rut-C30 and we introduced the cre1 gene in a Δpgi1 mutant. Both Δpgi1 and cre1+Δpgi1 mutants showed a pellet-like and growth as well as morphological alterations compared with Rut-C30. None of the mutants grew in media with fructose, galactose, xylose, glycerol or lactose but they grew in media with glucose, with fructose and glucose, with galactose and fructose or with lactose and fructose. No growth was observed in media with xylose and glucose. On glucose, Δpgi1 and cre1+Δpgi1 mutants showed higher cellulase activity than Rut-C30 and QM6a, respectively. But in media with lactose, none of the mutants improved the production of the reference strains. The increase in the activity did not correlate with the expression of mRNA of the xylanase regulator gene, xyr1. Δpgi1 mutants were also affected in the extracellular β-galactosidase activity. Levels of mRNA of the glucose 6-phosphate dehydrogenase did not increase in Δpgi1 during growth on glucose.

CONCLUSIONS

The ability to grow in media with glucose as the sole carbon source indicated that Trichoderma Δpgi1 mutants were able to use the pentose phosphate pathway. But, they did not increase the expression of gpdh. Morphological characteristics were the result of the pgi1 deletion. Deletion of pgi1 in Rut-C30 increased cellulase production, but only under repressing conditions. This increase resulted partly from the deletion itself and partly from a genetic interaction with the cre1-1 mutation. The lower cellulase activity of these mutants in media with lactose could be attributed to a reduced ability to hydrolyse this sugar but not to an effect on the expression of xyr1.

Authors+Show Affiliations

VTT, P,O, Box 1000, (Tietotie 2, Espoo), FIN-02044 VTT, Finland. carmenlimon@us.esNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

21609467

Citation

Limón, M Carmen, et al. "The Effects of Disruption of Phosphoglucose Isomerase Gene On Carbon Utilisation and Cellulase Production in Trichoderma Reesei Rut-C30." Microbial Cell Factories, vol. 10, 2011, p. 40.
Limón MC, Pakula T, Saloheimo M, et al. The effects of disruption of phosphoglucose isomerase gene on carbon utilisation and cellulase production in Trichoderma reesei Rut-C30. Microb Cell Fact. 2011;10:40.
Limón, M. C., Pakula, T., Saloheimo, M., & Penttilä, M. (2011). The effects of disruption of phosphoglucose isomerase gene on carbon utilisation and cellulase production in Trichoderma reesei Rut-C30. Microbial Cell Factories, 10, 40. https://doi.org/10.1186/1475-2859-10-40
Limón MC, et al. The Effects of Disruption of Phosphoglucose Isomerase Gene On Carbon Utilisation and Cellulase Production in Trichoderma Reesei Rut-C30. Microb Cell Fact. 2011 May 24;10:40. PubMed PMID: 21609467.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The effects of disruption of phosphoglucose isomerase gene on carbon utilisation and cellulase production in Trichoderma reesei Rut-C30. AU - Limón,M Carmen, AU - Pakula,Tiina, AU - Saloheimo,Markku, AU - Penttilä,Merja, Y1 - 2011/05/24/ PY - 2010/09/02/received PY - 2011/05/24/accepted PY - 2011/5/26/entrez PY - 2011/5/26/pubmed PY - 2011/9/14/medline SP - 40 EP - 40 JF - Microbial cell factories JO - Microb. Cell Fact. VL - 10 N2 - BACKGROUND: Cellulase and hemicellulase genes in the fungus Trichoderma reesei are repressed by glucose and induced by lactose. Regulation of the cellulase genes is mediated by the repressor CRE1 and the activator XYR1. T. reesei strain Rut-C30 is a hypercellulolytic mutant, obtained from the natural strain QM6a, that has a truncated version of the catabolite repressor gene, cre1. It has been previously shown that bacterial mutants lacking phosphoglucose isomerase (PGI) produce more nucleotide precursors and amino acids. PGI catalyzes the second step of glycolysis, the formation of fructose-6-P from glucose-6-P. RESULTS: We deleted the gene pgi1, encoding PGI, in the T. reesei strain Rut-C30 and we introduced the cre1 gene in a Δpgi1 mutant. Both Δpgi1 and cre1+Δpgi1 mutants showed a pellet-like and growth as well as morphological alterations compared with Rut-C30. None of the mutants grew in media with fructose, galactose, xylose, glycerol or lactose but they grew in media with glucose, with fructose and glucose, with galactose and fructose or with lactose and fructose. No growth was observed in media with xylose and glucose. On glucose, Δpgi1 and cre1+Δpgi1 mutants showed higher cellulase activity than Rut-C30 and QM6a, respectively. But in media with lactose, none of the mutants improved the production of the reference strains. The increase in the activity did not correlate with the expression of mRNA of the xylanase regulator gene, xyr1. Δpgi1 mutants were also affected in the extracellular β-galactosidase activity. Levels of mRNA of the glucose 6-phosphate dehydrogenase did not increase in Δpgi1 during growth on glucose. CONCLUSIONS: The ability to grow in media with glucose as the sole carbon source indicated that Trichoderma Δpgi1 mutants were able to use the pentose phosphate pathway. But, they did not increase the expression of gpdh. Morphological characteristics were the result of the pgi1 deletion. Deletion of pgi1 in Rut-C30 increased cellulase production, but only under repressing conditions. This increase resulted partly from the deletion itself and partly from a genetic interaction with the cre1-1 mutation. The lower cellulase activity of these mutants in media with lactose could be attributed to a reduced ability to hydrolyse this sugar but not to an effect on the expression of xyr1. SN - 1475-2859 UR - https://www.unboundmedicine.com/medline/citation/21609467/The_effects_of_disruption_of_phosphoglucose_isomerase_gene_on_carbon_utilisation_and_cellulase_production_in_Trichoderma_reesei_Rut_C30_ L2 - https://microbialcellfactories.biomedcentral.com/articles/10.1186/1475-2859-10-40 DB - PRIME DP - Unbound Medicine ER -