Techno-economic analysis of a bioprocess for the production of multienzyme solutions from the cake of babassu industrial processing: evaluation of five different inoculum propagation strategies

Multienzyme solutions produced via solid-state fermentation (SSF) represent an important intermediate in diverse bioprocessing technologies focused on the production of feedstocks for the biosynthesis of biofuels and platform chemicals. The production of crude enzymes via SSF needs more efficient and cost-effective processes. Five different inoculum strategies, involving two solid and three liquid approaches, were studied in order to test their ability to enhance the production of crude enzyme complexes containing exo- and endoamylases, proteases, cellulases, and xylanases. Experimental results including the propagation strategies and a standard SSF using babassu cake from an industrial plant as the sole source of nutrients were used to design the economics of the five different scenarios. Results of the final unit production cost and total capital investment suggest that liquid propagation strategies are more cost-competitive than solid strategies. Different sensitivity analyses carried out on the best scenario demonstrated that, among other analyzed variables, the plant capacity and the enzyme production yield show a significant effect on the principal economic indicators of the bioprocess. In comparison with the base case, the unit production cost and the total capital investment could be reduced up to 77 and 61 %, respectively.