D(-) Lactic Acid Production Using Corncob (Zea mays) Biomass via Multiple Parallel Fermentation (MPF) Elya Mufidah*, Bambang Dwi argo, Yusron Sugiarto, Adib Maula Mifzal, Audrya Nasywa Veliska, Jessica Sebastian Wijaya, Sarah Ramadhanty Hanifa
Bioprocess Engineering, Universitas Brawijaya, Indonesia 65148
Corresponding author: elyamufidah1985[at]ub.ac.id
Abstract
Corn-cob waste is rich in carbon, making it a promising feedstock for lactic-acid fermentation. This study aimed to (i) screen fungi that secrete biomass-degrading enzymes and lactic-acid bacteria (LAB) that produce D-lactic acid, and (ii) optimize multiple parallel fermentation (MPF) conditions for D-lactic-acid production from corn-cob substrate using the Taguchi method. Fungal candidates were evaluated for degradative potential and LAB for D-lactic-acid productivity, while temperature, pH, and substrate concentration were varied as control factors in the MPF system. Aspergillus niger and A. flavus showed the highest degradative activity, and Leuconostoc mesenteroides was the most effective D-lactic-acid producer. The optimal MPF conditions were 7 percent substrate, pH 6, and 39 degree celcius, yielding 17.8 percent D-lactic acid- temperature produced the largest signal-to-noise variation and was the most influential factor. These results indicate that corn-cob waste can serve as a viable carbon source for D-lactic-acid fermentation, supporting future production of PLA with improved thermal and mechanical properties.
