Development of biodegradable plastic materials used renewable resources are expected. Polylactic acid (PLA) is one of the biodegradable plastic which was produced from renewable resources by fermentation of starch and chemical polimerization. One isolate of the bacteria Lactobacillus plantarum was obtained from corn silage isolation and was homofermentative bacteria with lactic acid as the fermentation product. Lactic acid fermentation from corn starch medium was carried out by L. plantarum at room temperature and pH 6-6.5. Analysis of fermentation corn starch using HPLC and polarimeter showed that lactic acid fermentation by L. plantarum produced L(+) lactic acid. Productivity ofL( +)lactic acid was 2,6 mglml by the incubation of72 hours. This product will be followed by chemical polimerization to get polylactid acid (PLA). The technology process of PLA as biodegradable plastic will give an added value of com starch and can be competitive economically with the ordinary hydrocarbon plastics. Key words: Bioshyntesis, Polylactic acid, Lactobacillus plantarum. Lucia Indrarti, Elsy Rahimi dan Tati Pusat Penelitian Fisika (P2F) - LIPI
