Optimizing Submerged Fermentation Conditions of Aspergillus niger for Chitin Production

Chitin, a biopolymer precursor to chitosan, can be obtained from fungal sources. To ensure viable and scalable production, the use of alternative culture media and the optimization of cultivation parameters are essential. This study aimed to optimize the biomass production of Aspergillus niger via submerged fermentation to obtain chitin. The composition of the culture media and the bioprocess time were evaluated using a Factorial Design 2⁴. A subsequent Mixture Design was used to optimize carbon and nitrogen source concentrations, with fungal biomass and chitin yield as response variables. Scale-up was performed in a 5-L bioreactor under optimized conditions. As a result, the culture medium containing 7.5% wheat bran and 2.5% yeast extract was selected for cultivating A. niger, the predicted values for this condition were 4.40 g L^-1 of fungal biomass and 25.24% of chitin yield. After scaling up to a bioreactor, it was possible to obtain 10.20 g L^-1 and 4.95 g L^-1 ± 0.06 of biomass and chitin, after 84 h of bioprocess. The study demonstrates the potential of using alternative culture media for the submerged fermentation of A. niger and chitin production, with the possibility of increasing yields in the scale-up of this bioprocess.