Metabolic engineered of biocatalyst: A solution for PLA based problems ABSTRACT Poly lactic acid(PLA) is a biodegradable polymer used in many biomedical as well as in packaging Applications. Conventionally, PLA is produced by two method which is direct condensation of lactic acid and ring opening polymerization. The polymer produced from these conventional methods produced polymer which have low molecular weight. Conventional methods of PLA production requires catalyst which makes it unfit for biomedical Applications. Newer method utilizes metabolic engineering for direct production of PLA by fermentation. This can be done by introducing propionate CoA-transferases gene and polyhydroxyalkanoate synthase gene to E.coli for lactyl CoA production. This lactyl CoA by produces by gene manipulation produces poly lactic acid by fermentation. The polymer produced from this method have high quality and increased yield which makes it fit for biomedical applications. key words: biodegradable, E.coli, genetic engineering, lactic acid , lactyl CoA, polyhydroxyalkanoate (PHA), Poly lactic acid INTRODUCTION Polylactic acid (PLA) is rigid thermoplastic polymers that have semi crystalline or totally amorphous geometry, depending on the optical purity of the polymer backbone [1]. Lactic acid has …show more content…
Lactic acid is produced by two methods i.e, chemical method and fermentation method[3]. Chemical method utilizes petrochemical resources followed by addition of HCN and specific catalyst to produce lactic acid [3]. While fermentation methods utilizes renewable resources such as carbohydrate in a fermented broth to obtain lactic acid [3]. Optical purity of lactic acid is very important and hense is major addressed problem in production of PLA. Chemical method produces racemic mixture of both D(-) and L(+) lactic acid while fermentation methods produces only one optically pure form of D(-) or L(+) lactic acid