Glucose utilization and lactate production by Helicobacter pylori

The transport and incorporation of D-glucose into the human pathogen Helicobacter pylori was investigated employing radioactive tracer analysis and 1H and 13C nuclear magnetic resonance spectroscopy. The bacterium was found to utilize D-glucose contrary to the accepted view that it cannot catabolize carbohydrates. Under the experimental conditions employed, the rate of transport of [14C]glucose was 3.24 mmol min-1 (g protein)-1, and the rate of incorporation into the cellular mass was 1.06 mumol h-1 (g protein)-1. The utilization of [13C]glucose showed biphasic characteristics with a slower initial period followed by a phase with a rate of utilization at least an order of magnitude faster. The apparent rates of decline of glucose levels during both phases varied between strains and depended on the growth conditions of the bacteria prior to harvesting. The main product of glucose catabolism was identified as lactate. These findings provide new perspectives into the physiology of H. pylori and have implications for the active search to develop appropriate therapies for the micro-organism.