Valorization of Sugarcane Bagasse into Fermentable Sugars by Efficient Fungal Cellulolytic Enzyme Complex

The study aimed to identify an efficient cellulase producing fungus and to evaluate its potential for saccharification of sugarcane bagasse. A total of 17 fungi were isolated and among these, five isolates (JS4, JS5, JS6, JS8 and JS17) showed high cellulolytic index and were tentatively identified to be belonging to genera, i.e., Aspergillus and Penicillium . The fungal isolate JS7 exhibited significantly high total cellulase (43.52 U/L), endoglucanase (171.98 U/L) and β-glucosidase (78.65 U/L) activities, when grown under liquid shake flask conditions. BLAST analysis, multiple sequences and phylogenetic analysis showed that the isolate JS7 was highly similar with fungal strain Penicillium mallochii from gene bank. The enzyme extract from P. mallochii was concentrated using tangential ultrafiltration with 67.39% recovery of filter paper activity (total cellulase activity) and 1.75-fold purification. The saccharification of alkali pre-treated sugarcane bagasse with cellulase resulted in maximum reducing sugar yield of 651.60 mg/g with saccharification efficiency of 78.29%. Graphical Abstract