AMINO-ACID UTILIZATION BY HELICOBACTER-PYLORI

Utilization of aminoacids during growth by laboratory adapted and wild type Helicobacter pylori strains was investigated employing nuclear magnetic resonance spectroscopy and aminoacid analysis. All H. pylori strains tested showed growth rates with doubling times of approx, 11.5 hr in liquid cultures with semi-defined media or with defined aminoacid broth without carbohydrates. Fast utilization of several aminoacids at rates between 80 and 250 mu M/hr was observed in culture broths inoculated with approx. 10(7) cells/ml; and acetate, formate and succinate accumulated as catabolic products in the growth media. Suspensions of bacterial cells and lysates in isotonic solutions converted arginine, asparagine, aspartate, glutamine, and serine used as sole substrates at significant rates; and under these conditions the principal metabolic products observed were acetate, formate, succinate and lactate. The findings of the study indicated that H. pylori can survive employing aminoacids as the basic nutrients, and suggested some of these metabolites were utilized via fermentative pathways with common characteristics to those found in anaerobes.