Upcycling Agro-Industrial Waste into Bio-Based Chemicals: Indigenous Bacteria-Driven Volatile Fatty Acids Production from Cassava Pulp

Cassava pulp (CP) from cassava starch factories, a major agro-industry in Thailand, is a significant waste need to be concerned. As the world's leading exporter of cassava products, over 6.12 million tonnes of CP bio-waste generate annually. CP contains high residual starch entrapping in plant fiber. Additionally, CP itself contains indigenous fermentative bacteria such as Clostridium, Acinetobacter, Pantoea, and Lactobacillus, which can degrade organic matter into volatile fatty acids (VFAs). Therefore, this study aims to upcycle CP into bio-based chemicals (VFAs) without external microbial seed supplement. The indigenous microorganisms (IM) were boosted and enriched for C2-C4 VFAs production from CP. CP-enriched microorganisms (EM) can completely degrade starch and enhance acetic, propionic, and butyric acids with total VFAs of 644 mg acetic acid/g VSadded within 3 days. Whereas IM was produced lower and took longer time for VFAs production. However, high iso-valeric acid appeared after long incubation (≥ 5 days) of both microorganisms. Additionally, the dominant EM shifted to Lactobacillus. These results demonstrate that CP has high potential biomass resource with a robust indigenous microorganism, enhancing VFAs production for bio-based chemical applications. These findings highlight CP as a valuable substrate for sustainable bioconversion, contributing to waste valorization and circular bioeconomy development.