| dc.description.abstract | Liquid waste as consequences of tapioca and sago starch industries has caused environmental pollution. Mono- and disaccharides are dominant in the waste. These components are easily fermented to produce lactic acid, a potential raw material for polylactic acid (PLA). Objective of this research is to obtain the optimum fermentation condition of tapioca and sago starch industrial wastes in producing lactic acid. Liquid wastes from tapioca and sago starch industries were fermented using pure culture of Lactobacillus casei, Lb, delbruecki and Streptoccocus faecalis. Treatments of 2.5, 5 and 10% glucose addition and 5% glucose combined with 5% nitrogen were compared to none addition as a control. The effect of time fermentation was also observed. During the preliminary observation, Lb. casei exhibited more suitable as compared Lb. delbruecki and S. faecalis, hence only Lh. casei and sago isolate used at the main study. The results showed that tapioca waste produced lactic acid higher than that of sago starch waste. Treatment by adding 5% nitrogen and 5% glucose indicated the optimum condition for 4 days fermentation. At this condition, Lb. casei produce 1.98 % total acid using tapioca waste and 1.85% using sago starch waste. while culture isolated from sago waste produced 2.82% total acid using tapioca waste and 0.63% using sago starch waste. | en |
