http://hdl.handle.net/11189/5289 Thu, 13 Aug 2026 02:48:00 GMT 2026-08-13T02:48:00Z https://digitalknowledge.cput.ac.za:443/retrieve/26283/ http://hdl.handle.net/11189/5289 http://hdl.handle.net/11189/5509 Title: Kinetic description of the competitive interaction between lactate oxidizers and fermenters in a biosulfidogenic system Authors: Oyekola, Oluwaseun; Van Hille, RP; Harrison, Susan TL Abstract: In order to describe the relative predominance of lactate oxidation and fermentation under conditions of biological sulfate reduction, kinetic constants ( max and Ks ) were determined. Chemostat cultures under various conditions were employed. The kinetics of sulfate reduction and lactate utilization were investigated at residence times 1 to 5 d and feed sulfate concentrations of 1.0 to 10.0 g l-1 . At low lactate concentration, lower max and Ks characterized the lactate oxidizers (sulfate reducing bacteria) relative to the lactate fermenters. The kinetic properties of the lactate oxidizers (LO) were max of 0.2 h-1 and Ks of 0.6 g l-1 compared with a max of 0.3 h-1 and Ks of 3.3 g l-1 for the lactate fermenters (LF). The interaction between lactate oxidizers and lactate fermenters was demonstrated with the use of mathematical models. The LO outcompeted the LF under conditions of low lactate concentration (≤5 g l-1) and high sulfide concentration (0.3-0.6 g l-1). Lactate fermenters outcompeted the oxidizers under conditions of excess lactate concentration (>5 g l-1). The predictions by the mathematical models employed were in good agreement with the experimental results obtained for bacterial growth rates. The importance of an understanding of the impact of physicochemical conditions on the metabolic dominance in optimizing biological sulfate reduction (BSR) system, was highlighted in this study. Sat, 01 Jan 2011 00:00:00 GMT http://hdl.handle.net/11189/5509 2011-01-01T00:00:00Z http://hdl.handle.net/11189/5344 Title: Effect of culture conditions on the competitive interaction between lactate oxidizers and fermenters in a biological sulfate reduction system Authors: Oyekola, Oluwaseun; Harrison, Susan TL; Van Hille, RP Abstract: Kinetic constants (μmax and Ks) describing the predominance of lactate oxidation and fermentation were determined in chemostat cultures. The kinetics of sulfate reduction and lactate utilization were determined from 0.5 to 5 d residence times at feed sulfate concentrations of 1.0–10.0 g l−1. The kinetics of lactate fermentation in the absence of sulfate were investigated at residence times of 0.5–5 d. The lactate oxidizers (LO) were characterized by a μmax of 0.2 h−1 and Ks value of 0.6 g l−1 compared with a μmax of 0.3 h−1 and Ks of 3.3 g l−1 for the lactate fermenters (LF). Using mathematical models, it was shown that LO competed more effectively for lactate at low lactate concentrations (⩽5 g l−1) and high sulfide concentrations (0.5 g l−1). Lactate fermenters outcompeted the oxidizers under conditions of excess lactate (>5 g l−1) and low sulfide (0.014–0.088 g l−1). Sun, 01 Jan 2012 00:00:00 GMT http://hdl.handle.net/11189/5344 2012-01-01T00:00:00Z