POTENTIAL VALORIZATION OF AGRIBUSINESS STARCH WASTES AS LACTIC ACID SOURCE WITH LACTOBACILLUS AMYLOPHILUS(Abstract)

摘要

Up to now, the synthesis of polylactic acid relies essentially on the production of corn, which is a renewable resource. However, some problems as over exploitation of fertile soils, the increase of cereal price and the abusive uses of chemical fertilizer have been raised. Agri-food wastes show a promising alternative with their rich carbohydrate content, their quite stable composition and their availability. Therefore, they represent an appealing waste valorization target for an eventual polylactic acid production. Preliminary works have been done on starch waste. The bacteria, Lactobacillus amylophilus, has been selected for this valorization, based on its homofermentative, amylolytic and non-pathogenic characteristics. Prior to the production of polylactic acid, lactic acid fermentations have been realized on synthetic medium supplied with commercial wheat and potato starch to determine the maximal yield with this strain. Fermentation parameters such as preculture age and source, fermentation time, agitation, etc. have been determined followed by the replacement of those commercial starch sources with starch wastes. Other milestones are to find also waste sources for other microbial growth factors and minerals. According to the results, a life cycle analysis will be eventually realized.