Lactic Acid Production from Kitchen Refuses for Biodegradable Plastics Production

本项目的目的是阐明在未经灭菌的条件下，在厨房垃圾中停留的乳酸菌产生乳酸的基本原理。由此产生的乳酸将用于生产包括聚羟基烷酸(PHA)和聚乳酸在内的可生物降解塑料。在此条件下，每隔12h间歇调节pH至7，乳酸的产率可达89%以上，发酵pH迅速降至4，加入碱液后迅速恢复至7。结果表明，除乳酸菌外，其他细菌通过消化淀粉生成葡萄糖和补充双胺等辅助因子促进乳酸菌的生长，从而促进了冰酸的产生。另一方面，像大肠杆菌这样的有害细菌被间歇性的p1-i滴落破坏了。优势菌为植物乳杆菌和短乳杆菌。这一点得到了计算机模拟的证实。

The purpose of this project is to clarify the fundamentals for producing lactic acid from kitchen refuses by lactic acid bacteria who stay in the kitchen refuses under non-sterilized conditons. Lactic acid thus produced is to be used for the production of biodegradable plastics including polyhydroxyalkanoate (PHA) and poly-lactate. Lactic acid was efficiently produced under above conditions with a high electivity over 89% by adjusting pH at 7 intermittently every 12 hours ; the culture pH was swiftly dropped to 4 and returned rapidly to 7 by adding alkarine solution. It was suggested that the other bacteria than lactic acid bacteria contributed to the Ictic acid production by digesting starch to yield glucose and by supplying bitamines and other cofactors which assist the lactic acid bacterial growth. On the other hand, the harmful bacteria such as E-coli were ruined by intermittent p1-I drops. Lactobacillus plantarum and Lactobacillus brevis were found to be dominant bacteria. This was confirmed by a computer simulation.