Valorization of biomaterial side Streams: Kinetics of cassava pulp and its components degradation by Clostridium manihotivorum CT4T

• The first study on kinetic degradation of cassava pulp by C. manihotivorum CT4 T. • C. manihotivorum CT4 T efficiently degrades starch, cellulose, and hemicellulose. • Kinetic models were proposed to predict degradation of pure and complex substrates. • Data were validated against simulated degradation of individual components. • Carbon balance showed > 90% recovery, confirming credibility for scale-up. Cassava pulp (CP), a lignocellulosic side stream from starch extraction, is generated at approximately 2.5 tons per ton of starch, creating significant disposal challenges for the industry. Although anaerobic digestion (AD) offers a promising valorization pathway, the complex structure of CP limits microbial accessibility during hydrolysis and acidogenesis, the upstream stages that dictate overall AD performance. Kinetic parameters for CP bioconversion remain largely unexplored, particularly for Clostridium manihotivorum CT4 T (CT4 T ), a hydrolytic–acidogenic bacterium not previously studied for CP bioconversion kinetics. In this study, the degradation kinetics of individual CP components (cassava starch, cellulose, and hemicellulose) were systematically compared with actual CP using CT4 T . The strain displayed the highest maximum specific growth rate ( μ max ) on CP, with a μ max of 0.155 1/h, compared with 0.141 1/h on cassava starch, 0.027 1/h on cellulose and 0.032 1/h on hemicellulose. At 15 g/L initial CP, CT4 T achieved 66.75% overall degradation, complete starch utilization, and a final biomass concentration of 4.43 g/L. Kinetic modeling showed strong agreement with experimental observations (R 2 > 0.90), while carbon balance analysis indicated high recovery (90.04–95.47%), confirming metabolic consistency. Butyric acid (BA) was the predominant fermentation product across all substrates. Simulations based on individual component kinetics consistently overestimated CP highlight the influence of substrate interactions and structural complexity in real biomass systems. Overall, this study provides quantitative kinetic parameters describing the hydrolysis and acidogenesis of CP mediated by CT4 T , contributing critical data for improved modeling and the design of hydrolysis-focused or two-stage bioprocesses for CP valorization.