Generating the mutants of Phanerochaete chrysoporium RP 78 resistant to wood extractives for functional characterization of the detoxification system of white rot fungi

During the wood degradation process, wood decaying fungi develop different strategies to cope with wood extractives, which contain often antifungal compounds [1]. The aim of this work is to improve our understanding of those detoxification systems using the white rot Phanerochaete chrysoporium as model. For that, we have generated mutants of the monokaryotic strain Phanerochaete chrysoporium RP 78 by UV light exposure and then test their ability to grow in presence of wood extractives. The selected extractives were from wood of Bagassa guianensis Aubl., and Andira coriacea, species found in tropical forest (French Guiana) which are well-known for their high durability [2]. Dichloromethane extracts from wood of Prunus avium L. also have been selected since they contain several antifungal compounds [3].

Mutations in fungi have been generated by exposure of fungal conidia to ultraviolet radiation. Screening of mutants was carried out by selection of conidia able to grow on Malt Agar medium mixed with wood extractives.

Collections of 39 bag, 38 chy and 35 sam mutants which are able to germinate and grow in presence of acetonic extracts of Bagassa guianensis Aubl., dichloromethane extracts of Prunus avium L. and Andira coriacea respectively, were obtained. These mutants are able to germinate in the liquid medium containing a lethal concentration of extractives for the wild type RP 78.

To pursue this work, these obtained mutants will be characterized through, in particular, a scan genomic approach in order to identify the major genes involved in the detoxification mechanism in this fungus.

Key words: Phanerochaete chrysoporium, wood extractives, detoxification systems

References:

[1] Nicolas VALETTE, Fungal Biology Review, 2017

[2] Mariana Royer, International Biodeterioration & Biodegradation, 2012, 70, 55

[3] James McNulty, Phytochemistry, 2009, 70, 2040