Disruption of <it>Trichoderma reesei cre2</it>, encoding an ubiquitin C-terminal hydrolase, results in increased cellulase activity

• Main Authors: Denton Jai A, Kelly Joan M
• Format: Article
• Language: English
• Published: BMC 2011-11-01
• Series: BMC Biotechnology
• Online Access: http://www.biomedcentral.com/1472-6750/11/103

<p>Abstract</p> <p>Background</p> <p>The filamentous fungus <it>Trichoderma reesei </it>(<it>Hypocrea jecorina) </it>is an important source of cellulases for use in the textile and alternative fuel industries. To fully understand the regulation of cellulase production in <it>T. reesei</it>, the role of a gene known to be involved in carbon regulation in <it>Aspergillus nidulans</it>, but unstudied in <it>T. reesei</it>, was investigated.</p> <p>Results</p> <p>The <it>T. reesei </it>orthologue of the <it>A. nidulans creB </it>gene, designated <it>cre2</it>, was identified and shown to be functional through heterologous complementation of a <it>creB </it>mutation in <it>A. nidulans</it>. A <it>T. reesei </it>strain was constructed using gene disruption techniques that contained a disrupted <it>cre2 </it>gene. This strain, JKTR2-6, exhibited phenotypes similar to the <it>A. nidulans creB </it>mutant strain both in carbon catabolite repressing, and in carbon catabolite derepressing conditions. Importantly, the disruption also led to elevated cellulase levels.</p> <p>Conclusions</p> <p>These results demonstrate that <it>cre2 </it>is involved in cellulase expression. Since the disruption of <it>cre2 </it>increases the amount of cellulase activity, without severe morphological affects, targeting <it>creB </it>orthologues for disruption in other industrially useful filamentous fungi, such as <it>Aspergillus oryzae</it>, <it>Trichoderma harzianum </it>or <it>Aspergillus niger </it>may also lead to elevated hydrolytic enzyme activity in these species.</p>