A review on the lactic acid fermentation from low-cost renewable materials: Recent developments and challenges

Abstract Recently, lactic acid production from renewable materials has gained enormous attention due to the several functional properties it offers in different fields. The high yield productivity of lactic acid by utilizing economical and easily available substrates has received immense attraction in the petrochemical industry. Biomass or waste materials from various sources have become a significant concern because they cause severe environmental pollution if disposed of improperly. Hence, the employment of an integrated biorefinery platform for waste materials is an ideal option to produce high-value bio-products while remediating the waste. Optical pure lactic acid production through fermentation has gained interest due to its high potential applications in food, pharmaceutical, textiles, and cosmetic industries as well as highly promising packaging materials. The manufacturing of biodegradable bioplastic from polylactic acid materials is a green alternative to that derived from petrochemicals. However, high manufacturing costs have impeded the widespread application of polylactic acid due to the high cost of lactic acid production. This review paper summarizes the most recent advancements and challenges in pure lactic acid production from various substrates and conventional processes, including pretreatment and enzymes hydrolysis and fermentative technologies. Moreover, a detailed analysis of the techno-economic feasibility, downstream processing, and lactic acid purification techniques are also discussed.