[Succinic acid production using mobile bed of immobilized Actinobacillus succinogenes in alginate]. / Obtinerea acidului succinic prin fermentatie cu strat mobil de Actinobacillus succininogenes.

UNLABELLED: This work investigates the production of succinic acid by immobilized A. succinogenes cells, using a bioreactor with stirred/mobile bed of biocatalysts. MATERIAL AND METHOD: The experiments have been carried out for different sizes of biocatalysts particle, under substrate and product inhibitory effects. RESULTS: The results indicated that the inhibitory effects could be diminished by cells immobilization, the substrate consumption rate increasing with the increase of biocatalyst particle size. Moreover, the biocatalysts can be used for many fermentation cycles.

External and internal glucose mass transfers in succinic acid fermentation with stirred bed of immobilized Actinobacillus succinogenes under substrate and product inhibitions.

This paper is dedicated to the study on the external and internal mass transfers of glucose for succinic acid fermentation under substrate and product inhibitions using a bioreactor with stirred bed of immobilized Actinobacillus succinogenes cells. By means of the substrate mass balance for a single particle of biocatalysts, considering the kinetic model adapted for both inhibitory effects, specific mathematical models were developed for describing the profiles of the substrate concentration in the outer and inner regions of biocatalysts and for estimating the substrate mass flows in the liquid boundary layer surrounding the particle and inside the particle. The values of the mass flows were significantly influenced by the internal diffusion velocity and rate of the biochemical reaction of substrate consumption. These cumulated influences led to the appearance of a biological inactive region near the particle center, its magnitude varying from 0 to 5.3% of the overall volume of particles.