Lactic acid concentrations were determined by a high performance liquid chromatography system equipped with a UV detector at 210 nm. A Rezex ROA (300 x 7.8 mm, Phenomenex) column was eluted with 5 mM H2SO4 as the mobile phase at a flow rate of 0.4 mL/min and the column temperature was maintained at 60°C. Reducing sugars were measured using the 3.5-dinitrosalicylic acid method (Miller, 1959). Cell growth was determined using a spectrophotometer at 650 nm (OD650) following centrifugation and washing of the cells. The dry mass was determined from a standard curve of optical density versus dry mass.