LACTIC ACID PRODUCTION FROM SOLID CATFISH WASTE (MANURE)

The aim of this work was to study the solid waste (manure) produced by catfish as a potential feedstock for the production of lactic acid via fermentation. The solid waste contains high levels of nutrients for lactic acid bacteria which eliminated the need for external nutrient source such as yeast extract, peptone and/or corn steep liquor. Simultaneous Saccharificiaton and Co-Fermentation (SSCF) was applied using enzyme and Lactobacillus pentosus (ATCC-8041). Different loadings of enzyme and solid waste were tested to find the optimal operation conditions for SSCF. The lactic acid concentration achieved at 15% solid waste was 35.7 g/L. Solid catfish waste could also combine with other solid waste, to increase the final lactic acid concentration. When the mixed feedstock of fish waste and paper mill sludge was used, the lactic acid concentration increased to 43.1 g/L at 12% equivalent solid loading. The catfish waste was proved to be a potential feedstock to provide both carbon and nutrient source for LA production, which could be used as a sole substrate or could be combined with other lignocellulosic materials.