Fermentation of L-lactic Acid and Synthesis of Poly(L-lactic acid)

L-lactic acid is widely used in food,pharmaceutical,cosmetic and industrial fields.Recent years,with the constant shortage of fossil resources,many synthetic polymer materials production has been limited.Therefore,L-lactic acid,which is maded based on biomass resources has been widely used for processing into poly L-lactic acid and other environment-friendly biodegradable materials.Due to the increasing demand for L-lactic acid,the efficient production of low-cost L-lactic acid has become particularly important.The breeding of L-lactic acid producing strain,the cheap resources development and utilization for L-lactic acid fermentation,L-lactic acid fermentation process and purification of L-lactic acid products are systematiclly focused on.For strains breeding,a number of excellent L-lactic acid producers have been obtained which can fermented cheap carbon source to lactic acid efficiently,and strains with low nutritional needs were also breeded.However,strains that have the integrated advantages needs to be further breeding;For fermentation substrates,application of a variety of cheap,abundant carbon sources for lactic acid efficiency fermentation have been already developed,but industrial-scale application of these substrates remains to be further studied;For fermentation process,environment-friendly and low labor intensity fermentation process has been developped,but the problem of high cost is still exists.For purification of products,the post-extraction process has been simplified through the production of breeding species with low nutritional requirements and the using of new fermentation process,but the actual applications still under the constraints of the high cost of the fermentation process.Finally,a short review on the chemical processing of poly L-lactic acid and biodegradation of poly L-lactic acid,and some suggestions were given.