Comparative glucose and pentose utilization by a thermophilic Lactobacillus

Abstract A thermophilic Lactobacillus , isolate VB183, was tested for comparative glucose and pentose utilization. The possible adverse effect of high concentrations of metabolic end products on cell yield was lessened or eliminated by using low substrate concentrations. Possible growth due to intracellular reserve material, was counteracted by starving the cells for 90 min before being used as inoculant. Isolate VB183 exhibited a higher growth rate on glucose (μ= 1.08 h⁻¹) than on ribose (μ= 0.76 h⁻¹). L. salivarius was included as a pentose non-fermenting control and showed no significant difference between growth on basal medium with and without ribose. VB183 was also found to utilize l (+)-arabinose but not d (−)-arabinose, stressing the importance of the isomer of the sugars tested.