Silvia Brock, Anja Kuenz, U. Prüße
Jan 23, 2019
Citations
1
Influential Citations
14
Citations
Journal
Fermentation
Abstract
d-lactic acid is a building block for heat resistant polylactic acid, a biobased polymer with a high potential. Nevertheless, an economically efficient industrial process for d-lactic acid production still needs to be implemented. Yeast extract is an expensive nutrient source, which is used to fulfill the complex nutritional requirements in lactic acid fermentations. The substitution of yeast extract by cheap alternative nutrient sources is a challenge in many fermentation processes. In this study, chemical and enzymatic hydrolysis techniques for protein rich agricultural residues and their effectiveness are compared, as well as their impact on the d-lactic acid production of Sporolactobacillus inulinus. An efficient substitution of yeast extract could be achieved by a variety of agricultural residues, hydrolysed with 3M H2SO4, demonstrating the much higher versatility and effectiveness of this method compared to enzymatic methods. In a fed-batch experiment with chemically hydrolyzed rapeseed meal and minimal supplementation, a lactic acid titer of 221 g L−1 and an overall productivity of 1.55 g (L h)−1 (96% yield) were obtained.