Fermentation of de-oiled algal biomass by Lactobacillus casei for production of lactic acid

De-oiled algal biomass (algal cake) generated as waste byproduct during algal biodiesel production is a promising fermentable substrate for co-production of value-added chemicals in biorefinery systems. We explored the ability of Lactobacillus casei 12A to ferment algal cake for co-production of lactic acid. Carbohydrate and amino acid availability were determined to be limiting nutritional requirements for growth and lactic acid production by L. casei. These nutritional requirements were effectively addressed through enzymatic hydrolysis of the algal cake material using alpha-amylase, cellulase (endo-1,4-beta-d-glucanase), and pepsin. Results confirm fermentation of algal cake for production of value-added chemicals is a promising avenue for increasing the overall cost competiveness of the algal biodiesel production process.