Identification of the pigment and its role in UV resistance in Paecilomyces variotii, a Chernobyl isolate, using genetic manipulation strategies

Fungi produce secondary metabolites that are not directly involved in their growth, but often contribute to adaptation extreme environmental stimuli and enable survival. Conidial pigment or melanin is one of the produced naturally by a polyketide synthesis (PKS) gene cluster several filamentous fungi known protect these from radiation conditions. Several pigmented melanized have been shown grow under conditions at Chernobyl nuclear accident site. Some fungi, including Paecilomyces variotii, were observed towards source radiation. Therefore, this study, we wanted identify if P. contributes providing protection against condition. We first identified PKS responsible for variotii confirmed its role UV irradiation through CRISPR-Cas9 mediated deletion. This report describes use CRISPR methodology create deletions variotii. Further, showed fungus, was inhibited DHN-melanin pathway inhibitors, indicating fungus does melanin. then synthesized as naptho-pyrone Ywa1, heterologously expressing Aspergillus nidulans. The results obtained will further aid understanding mechanistic basis resistance.