Bradfield, M.F.A. (Michael Ford Alexander)Nicol, Willie2016-02-102016-02Bradfield, MFA & Nicol, W 2016, 'Continuous succinic acid production from xylose by Actinobacillus succinogenes', Bioprocess and Biosystems Engineering, vol. 39, no. 2, pp. 233-244.1615-7591 (print)1615-7605 (online)10.1007/s00449-015-1507-3http://hdl.handle.net/2263/51324Continuous, anaerobic fermentations of D-xylose were performed by Actinobacillus succinogenes 130Z in a custom, biofilm reactor at dilution rates of 0.05, 0.10 and 0.30 h-1. Succinic acid yields on xylose (0.55–0.68 g g-1), titres (10.9–29.4 g L-1) and productivities (1.5–3.4 g L-1 h-1) were lower than those of a previous study on glucose, but product ratios (succinic acid/acetic acid = 3.0–5.0 g g-1) and carbohydrate consumption rates were similar. Also, mass balance closures on xylose were up to 18.2 % lower than those on glucose. A modified HPLC method revealed pyruvic acid excretion at appreciable concentrations (1.2–1.9 g L-1) which improved the mass balance closure by up to 16.8 %. Furthermore, redox balances based on the accounted xylose consumed and the excreted metabolites, indicated an overproduction of reducing power. The oxidative pentose phosphate pathway was shown to be a plausible source of the additional reducing power.en© Springer-Verlag Berlin Heidelberg 2015. The original publication is available at : http://link.springer.com/journal/449 ,Actinobacillus succinogenesContinuous fermentationBiofilmRedox balanceSuccinic acidXylosePostprint Article