Isolation and screening for cellulase producing fungi from sugarcane bagasses using submerged fermentation conditions

Agro-industrial residues, particularly sugarcane bagasse, pose significant environmental challenges due to their underutilization and the pollution resulting from open-field burning. Nevertheless, these residues are rich in sugars, minerals, and proteins, making them valuable raw materials for diverse industrial applications, including enzyme production. The current aimed to isolate filamentous fungi from sugarcane bagasse and assess their potential for cellulase production under submerged fermentation conditions. Eleven fungal species related to two genera (Aspergillus and Fusarium) were recovered from the experimented sugarcane baggase samples direct-plating technique. Aspergillus (10 species) was the most frequently occurring genus accounting the highest population, whereas Fusarium (F. solani) was the lowest frequency of occurrence. Aspergillus flavus emerged as the most dominant isolate, recording the highest colony-forming units (CFU) as well as the highest frequency of occurrence. The investigated fungal isolates exhibited variable potentials in producing extracellular cellulases, indicating differences in their enzymatic efficiency concerning the hydrolysis of carboxymethyl cellulose. Notably, several isolates of Aspergillus flavus demonstrated a high cellulase production, whereas Fusarium solani showed comparatively low enzymatic activity. Under submerged fermentation, the secondary screening for exoglucanase production revealed that Aspergillus flavus isolate no. 40 yielded 0.816 U/mL of exoglucanase activity, while Aspergillus foetidus isolate no. 32 exhibited significant production, with a specific activity of 2.199 U/mg protein, indicating strong enzymatic potential. The current study highlights the feasibility of utilizing sugarcane bagasse as a renewable resource for enzyme production, promoting both waste valorization and sustainable biotechnological applications in various industries.