Isolation, screening and identification of ligno-cellulolytic fungi from northern central Morocco

Abstract

Description of the subject. Extracellular enzymes from filamentous fungi are increasingly used in eco-friendly biotransformation processes. Their relevant technological role and their stability towards extreme process conditions make of them the first sustainable solution for the elaboration of bio-based products from biomass conversion. Objectives. This paper describes the isolation of filamentous fungi from decaying plant material in the region of Meknes (northern central Morocco) and the assessment of their ability to breakdown lignocellulose. The objective is to select performant fungi with enzymatic machinery adapted to local environment and with potential for the breakdown of the regional specific lignocellulosic by-products into potentially high-value molecules. Method. Cereals, decaying wood, olive-pomace and -pulp and their composts were used to isolate lignocellulolytic fungi. One hundred twenty-seven pure strains were isolated and screened at 25 °C on selective media with cellulose or lignin as the sole carbon source. Performant strains were validated for the production of ligno-cellulolytic enzymes and identified using molecular technique. Results. Twenty-eight fungi had mycelial diameter on cellulose ≥ 6 cm and cellulolytic index ≥ 0.9. Twenty-two strains had the same profile on lignin medium. The production of endoglucanase, lignin peroxidase and manganese peroxidase enzymes was confirmed in performant strains using qualitative assay and molecular identification revealed that the best performing fungi were Mucor circinelloides, Mucor racemosus, Penicillium brasilianum, Penicillium crustosum, Paecilomyces sp., Fusarium oxysporum, Fusarium solani, Aspergillus fischeri, Curvularia spicifera, Humicola grisea, Trichoderma atroviride and Cosmospora viridescens. Measurement of ligno-cellulolytic activities revealed that Penicillium and Fusarium strains mainly from wood decay and compost had the best profiles among performing strains. Conclusions. Isolated fungi are high decomposers of biomass and represent a prominent solution to develop green bioprocesses in the region.