Isolation of fungal strains for biodegradation and saccharification of microalgal biomass

Products from microalgae have multiple commercial applications including for nutrition, health and fuel uses, but the breakage and release of products from biomass remains a challenge, particularly for microalgal strains with thick cell walls. Fungal strains were isolated due to their ability to degrade microalgal biomass of Parachlorella hussii, Hindakia tetrachotoma and Jaagichlorella luteoviridis that was buried in soil at 25°C for 8 weeks. Fungal isolates were identified by sequencing, with the three most ubiquitous strains identified as Fusarium solani, Doratomyces nanus and Actinomucor elegans. Crude enzyme extracts from these strains were used to quantify the saccharification of intact or lipid-extracted Chlorella vulgaris biomass. The D. nanus extract gave the highest saccharification efficiency of 57% from the intact biomass and 76% from the lipid-extracted biomass, without need for any pre-treatment. Outcomes of this study can improve the design of microbial enzymes to efficiently degrade microalgal biomass for various industrial applications.