Identification of laccase genes in Trichoderma asperellum Ts93

Although extensive research efforts have been dedicated to characterizing the laccase from white-rot fungus, little information is available on laccases from Trichoderma spp. A copper-tolerant strain with the ability to produce laccase was isolated and identified as Trichoderma asperellum Ts93. Under optimized conditions, the maximum laccase activity was 1.96 U/ml. The genome-wide survey of Ts93 revealed the presence of seven putative laccase genes that all contained the conserved domain and were divided into three different phylogenetic groups. Among these genes, three contained the four copper-binding conserved regions. The expression profiles acquired through real-time quantitative PCR analysis showed that five of the seven genes were significantly upregulated in response to laccase activity. Seven laccase genes in T. asperellum were identified for the first time by whole-genome sequencing followed by phylogenetic analysis. The findings of this work provide valuable information for the functional analysis of laccase genes in Trichoderma spp.