Metabolic Activities of Pseudomonads in Batch Cultures in Extract of Minced Lamb

J Appl Bacteriol. 1994 Dec;77(6):613-20. doi: 10.1111/j.1365-2672.1994.tb02809.x.

Abstract

Pseudomonas fragi, Ps. lundensis and Ps. fluorescens were studied in axenic batch cultures growing in a lamb juice (pH 6.0) aerobically or in an atmosphere (Ps. fragi only) enriched with carbon dioxide at 4 degrees C. With all but a glucose dehydrogenase-deficient strain of Ps. fluorescens there was a sequential catabolism of glucose and lactate. Diauxic growth was observed in a nutrient-deficient meat juice supplemented with glucose and lactate. A transient peak in the concentration of gluconate and pyruvate was associated with the catabolism of glucose and lactate respectively. With Ps. fluorescens deficient in glucose dehydrogenase there was simultaneous catabolism of glucose and lactate. The stereoisomers of lactate were catabolized simultaneously in a laboratory medium. Glucose-6-phosphate was oxidized to 6-phosphogluconate by Ps. fragi and Ps. lundensis under aerobic conditions only. Creatine and creatinine were catabolized by Ps. fragi under aerobic conditions only. There was a slight decrease in the concentration of total amino acids (ninhydrin-reactive material) during the exponential phase of growth. The results suggest that the dominance of Ps. fragi in the climax populations in meat is due to catabolism of amino acid related substrates, creatine and creatinine.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Creatine / metabolism
  • Creatinine / metabolism
  • Culture Media / metabolism*
  • Food Microbiology
  • Gluconates / metabolism
  • Glucose / metabolism
  • Lactates / metabolism
  • Meat Products / microbiology*
  • Muscle, Skeletal
  • Pseudomonas / growth & development
  • Pseudomonas / metabolism*
  • Pseudomonas fluorescens / growth & development
  • Pseudomonas fluorescens / metabolism
  • Pyruvates / metabolism
  • Pyruvic Acid
  • Selection, Genetic
  • Tissue Extracts

Substances

  • Culture Media
  • Gluconates
  • Lactates
  • Pyruvates
  • Tissue Extracts
  • Pyruvic Acid
  • Creatinine
  • Glucose
  • Creatine
  • gluconic acid
  • 6-phosphogluconic acid