Lactic acid fermentation using dairy manure as the sole carbon and nitrogen source

Abstract

L-Lactic acid is one of the most important organic acids utilized in food, pharmaceutical, and chemical industries. A major and unique contribution that lactic acid can make to a renewable environment is its use in the production of biodegradable plastics that can replace the fossil-fuel-based non-biodegradable plastic materials widely used in many aspects of life today, leading to the reduction of global consumption of the diminishing petroleum resources. This project is aimed at exploring a novel idea of producing lactic acid from dairy manure, a vast renewable resource, via batch fermentation by microorganisms such as fungi, with emphasis on the feasibility and possibility of microbial use of the nutrients in the manure (carbon and nitrogen source) for lactic acid production. The specific objectives of this project can be summarized as follows: 1) develop effective processes for dairy manure hydrolysis by fungi by determining the most effective microbial culture or flora and the optimal operating parameter values for hydrolysis and 2) investigate the feasibility and techniques of converting the hydrolysates from dairy manure into lactic acid through fermentation without external nutrients and optimize the fermentation conditions to enhance lactic acid production.