(603f) Lactic Acid Fermentation On Softwood Prehydrolysate by Lactobacillus Delbrueckii

Conversion from lignocullulosic biomass into biofuels has been extenstivley investigated recently. However, the whole bioconversion process is still not cost-effective. Developing high-value co-products from biomass prehydrolysate will generate extra revenue to this bioconversion process and become critical to the economic viability of biofuels production.  Lactic acid has been classified as valued co-products since it could be used in the food, cosmetic, pharmaceutical chemicals, and biodegradable polymers. The bioconversion process typically includes pretreatment, enzymatic hydrolysis and fermentation.  High temperature pretreatment with acid  is required to break down the recalcitrant structure of cellulose, hemicellulose and lignin, the harsh condition also generates degraded compounds form carbohydrates and lignin, which are toxic to fermentative microorganisms and inhibit their metabolism, consequently reduces the fermentation rate and yield. The objective of this study is to investigate the fermentability of the softwood prehydrolysate and detoxify the prehydrolysate with different methods to maximize the fermentation yield of lactic acid using Lactobacillus delbrueckii. It is has been proved pH control was essential for lactic acid fermentation by L. delbrueckii and pH is regulated by adding CaCO₃ in this study. Different detoxification methods including alkaline detoxification and H₂O₂ oxidation detoxification has been investigated.