Succinic acid fermentation with immobilized Actinobacillus succinogenes using hydrolysate of carbohydrate-rich microalgal biomass.

This work aimed to study the efficiency of polyvinyl-alcohol-immobilized Actinobacillus succinogenes ATCC55618 for succinic acid (SA) production. Batch fermentation (pH 7, 45% CO gas at 0.04 vvm) using glucose (40 g L) resulted in SA titer, 26.7 g L; productivity, 3.33 g Lh; yield, 0.621 g g1. Fed-batch mode with cyclic extrication of SA from the medium markedly enhanced the yield to 0.699 g g and concentration to 59.5 g L. Batch fermentation using sugars derived from Chlorella vulgaris ESP-31 without yeast extract gave a SA productivity, concentration, and yield of 1.82 g Lh, 36.1 g L, and 0.720 g g1, respectively. Furthermore, continuous fermentation (at 6 h HRT) with microalgal sugar improved the productivity and yield to 3.53 g Lh and 0.62 g g, respectively, which is comparable to those obtained by using glucose. This study reports the highest productivity for SA fermentation using microalgae-derived sugars.