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

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.

Enzymatic Potential of Filamentous Fungi as a Biological Pretreatment for Acidogenic Fermentation of Coffee Waste

“…Other studies also reported cellulose degradation when treating the biomass with T. versicolor , leading to significant decreases in SCOA production [ 63 , 64 ]. This could justify the low SCOA production of PvSSF, since P. variotii is known to have high cellulosic and hemicellulosic activities [ 65 ].…”

Lignocellulolytic Biocatalysts: The Main Players Involved in Multiple Biotechnological Processes for Biomass Valorization

“…In order to obtain an efficient cocktail, some parameters must be taken into account, such as microorganisms’ behavior when cultivated on different substrates, identifying the types of enzymes they produce in each case, and which enzymes are necessary for every kind of substrate degradation [ 60 ]. Various approaches can be used for enzymatic cocktails production, such as combinations of distinct species of fungi [ 248 , 249 , 250 , 251 ], bacteria [ 252 , 253 , 254 ], or even fungi and bacteria [ 255 , 256 , 257 ]. Furthermore, strategies for optimizing an enzymatic cocktail may include supplementation with a specific enzyme, be it hydrolytic or not, or supplementation with surfactants or other chemicals [ 247 ].…”

“…Several studies have already shown the efficiency of bioprospecting in searching for lignocellulolytic microorganisms aiming at producing enzymatic cocktails. To date, metagenomic analyses have also resulted in the identification of numerous potential lignocellulolytic enzymes [ 233 , 249 , 380 , 382 , 383 , 384 , 385 , 386 ]. Shotgun analysis of a bacterial consortium enriched with carboxymethylcellulose, for example, resulted in the reconstruction of six complete genomes, four of which were new, including Bacillus thermozeamaize , Geobacillus thermoglucosidasiu , and Caldibacillus debillis .…”

Production of Different Biochemicals by Paenibacillus polymyxa DSM 742 From Pretreated Brewers’ Spent Grains

“…Glucose and xylose are the main carbohydrates that can be obtained after pretreatment of residual lignocellulosic raw materials. The choice of the pretreatment method greatly influences the concentration of the aforementioned fermentable sugars (Mar detko et al, 2018(Mar detko et al, , 2021. Bacterium P. polymyxa can use glucose and xylose for its metabolic needs (Okonkwo et al, 2021).…”