Evaluation of succinic acid continuous and repeat-batch biofilm fermentation by Actinobacillus succinogenes using plastic composite support bioreactors

• Published in: Applied microbiology and biotechnology 2004-11, Vol.65 (6), p.664-670
• Main Authors: Urbance, S.E, Pometto, A.L. III, DiSpirito, A.A, Denli, Y
• Format: Article
• Language: English
• Subjects: Acid production; Acids; Actinobacillus - growth & development; Actinobacillus - metabolism; Actinobacillus succinogenes; Bacteria; batch fermentation; Biofilms; Biofilms - growth & development; Biological and medical sciences; Bioreactors; Biotechnology; Biotechnology - methods; Cells, Immobilized; continuous fermentation; Culture Media - chemistry; Fermentation; Fundamental and applied biological sciences. Psychology; Glucose - metabolism; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; Microbiology; Peptones; Plastics; Soybeans; Succinic Acid - metabolism; Yeasts
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-004-1634-2

Continuous and repeat-batch biofilm fermentations using Actinobacillus succinogenes were performed with immobilized and suspended-cell systems. For the immobilized continuous system, plastic composite supports (PCS) containing 50% (w/w) polypropylene (PP), 35% (w/w) ground soybean hulls, 5% (w/w) dried bovine albumin, 2.5% (w/w) soybean flour, 2.5% (w/w) yeast extract, 2.5% (w/w) dried red blood cells, and 2.5% (w/w) peptone, or PP tubes (8.5 cm in length) were arranged around the agitator shaft in a grid formation. Agitation was controlled at 125 rpm and 150 rpm. Samples were taken at dilution rates of 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2 h(-1) and analyzed for succinic acid production and glucose consumption (g l(-1)). For PCS bioreactors, the highest final succinic acid concentrations (10.1 g(-1), 10.4 g l(-1)) and percentage yields (62.6%, 71.6%) occurred at the dilution rate of 0.2 h(-1). PCS disks were evaluated in a repeat-batch biofilm reactor. Suspended-cell batch fermentations were performed in flasks and a repeat-batch bioreactor. The maximum concentration of succinic acid produced was 40 g l(-1). Peak succinic acid percentage yields in continuous and repeat-batch fermentations of A. succinogenes were observed in suspended-cell continuous fermentations at a dilution rate of 1.0 h(-1) (76.2%) and in PCS repeat-batch fermentations with an initial glucose concentration of 40 g l(-1) (86.7%).