<i>laeA</i> Gene Introduction Strategy Enabling the Construction of a Prolific Fungal Secondary Metabolite Library

LaeA is a putative nuclear methyltransferase protein that epigenetically influences secondary metabolite production in fungi. LaeA has drawn attention as one of the promising approaches to activate fungal chemical production, and the <i>laeA</i> gene has been introduced into some fungal strains with the aim of producing secondary metabolic changes mainly based on the evaluation of mycotoxicity. However, these studies were applied for limited fungal species, and its utility and versatility for broad fungal species remained unclear. In this study, 47 strains were selected composed of three different genera, <i>Pochonia</i> spp., <i>Gamszarea kalimantanensis</i>, and <i>Lecanicillium</i> spp., which have never been modified with the <i>laeA</i> gene. We obtained a total of 125 mutants with <i>laeA</i> genes for our fungal strain library. The chemical productivity and the biological activity of the library were analyzed, and two natural products, radicicol (<b>1</b>) and sch210972 (<b>2</b>), were isolated in more than 10-fold the yield of the parent strains.