Valorization of cassava waste for pullulan production by Aureobasidium pullulans MTCC 1991

The interest in pullulan produced from industrial wastes has substantially increased due to its industrial applications. The major constraint in pullulan production is expensive and low yield. In this study, attempts were made on the evaluation of media components for maximum pullulan production from Aureobasidium pullulans MTCC 1991 using cassava waste in solid-state fermentation. A statistical approach was scrutinized to evaluate the effects of yeast extract, K₂HPO₄, (NH₄)₂SO4, MgSO₄⋅7H₂O, and NaCl on pullulan production. The optimal conditions eliciting the maximum pullulan yield (6.45 g pullulan/L of culture broth) were found to be 0.6 g/L yeast extract, 3 g/L K₂HPO₄, 0.2 g/L (NH₄)₂SO₄, 0.3 g/L MgSO₄⋅7H₂O, and 1 g/L NaCl. The produced pullulan was extracted using the solvent precipitation method and characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy spectroscopic analysis that confirmed pullulan with linear α (1–6) linkage. The results revealed that cassava waste could be used as an effective carbon source for the production of pullulan. © The Author(s) 2020.