Screening of Lignocellulolytic Enzyme Activities in Fungal Species and Sequential Solid-State and Submerged Cultivation for the Production of Enzyme Cocktails

Nenad Marđetko; Antonija Trontel; Mario Novak; Mladen Pavlečić; Blanka Didak Ljubas; Marina Grubišić; Vlatka Petravić Tominac; Roland Ludwig; Božidar Šantek

doi:10.3390/polym13213736

Screening of Lignocellulolytic Enzyme Activities in Fungal Species and Sequential Solid-State and Submerged Cultivation for the Production of Enzyme Cocktails

Polymers (Basel). 2021 Oct 28;13(21):3736. doi: 10.3390/polym13213736.

Authors

Nenad Marđetko¹, Antonija Trontel¹, Mario Novak¹, Mladen Pavlečić¹, Blanka Didak Ljubas¹, Marina Grubišić¹, Vlatka Petravić Tominac¹, Roland Ludwig², Božidar Šantek¹

Affiliations

¹ Laboratory for Biochemical Engineering, Industrial Microbiology and Malting and Brewing Technology, Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, 10000 Zagreb, Croatia.
² Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, BOKU-University of Natural Resources and Life Sciences, 1190 Vienna, Austria.

Abstract

Various fungal species can degrade lignocellulolytic materials with their enzyme cocktails composed of cellulolytic and lignolytic enzymes. In this work, seven fungal species (Mucor indicus DSM 2185, Paecilomyces variotii CBS 372.70, Myceliophthora thermophila CBS 663.74, Thielavia terrestris CBS 456.75, Botryosphaeria dothidea JCM 2738, Fusarium oxysporum f.sp. langenariae JCM 9293, and Fusarium verticillioides JCM 23107) and four nutrient media were used in the screening for effective lignocellulose degrading enzymes. From the seven tested fungi, F. oxysporum and F. verticilliodes, along with nutrient medium 4, were selected as the best medium and producers of lignocellulolytic enzymes based on the determined xylanase (>4 U mg^-1) and glucanase activity (≈2 U mg^-1). Nutrient medium 4 supplemented with pretreated corn cobs was used in the production of lignocellulolytic enzymes by sequential solid-state and submerged cultivation of F. oxysporum, F. verticilliodes, and a mixed culture of both strains. F. oxysporum showed 6 times higher exoglucanase activity (3.33 U mg^-1) after 5 days of cultivation in comparison with F. verticillioides (0.55 U mg^-1). F. oxysporum also showed 2 times more endoglucanase activity (0.33 U mg^-1). The mixed culture cultivation showed similar endo- and exoglucanase activities compared to F. oxysporum (0.35 U mg^-1; 7.84 U mg^-1). Maximum xylanase activity was achieved after 7 days of cultivation of F. verticilliodes (≈16 U mg^-1), while F. oxysporum showed maximum activity after 9 days that was around 2 times lower compared to that of F. verticilliodes. The mixed culture achieved maximum xylanase activity after only 4 days, but the specific activity was similar to activities observed for F. oxysporum. It can be concluded that both fungal strains can be used as producers of enzyme cocktails for the degradation of lignocellulose containing raw materials, and that corn cobs can be used as an inducer for enzyme production.

Keywords: Fusarium sp.; different fungal species; lignocellulolytic enzymes; pretreated corn cobs; sequential solid state and submerged cultivation; single and mixed fungal species cultivation.

Abstract

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