Effects of Environmental Factors on Leucine Catabolism by Carnobacterium Piscicola

Int J Food Microbiol. 2003 Mar 25;81(3):177-84. doi: 10.1016/s0168-1605(02)00227-1.

Abstract

The metabolites from leucine degradation are involved in dry fermented sausage aroma. The catabolism of leucine by a strain of Carnobacterium piscicola was studied directly in the growth medium with 3H-labelled leucine to investigate the effect of five parameters: phase of growth, pH, oxygen, glucose and alpha-ketoisocaproic acid. Resting cells (RC) were also incubated with 3H-labelled leucine. The radioactive metabolites from leucine catabolism were analysed by high performance liquid chromatography (HPLC). At pH 5.4 and 7.2, the main metabolites detected were 3-methyl butanal, 3-methyl butanol and alpha-ketoisocaproic acid. At pH 6.5, the leucine catabolism was maximum and was characterised by a high production of 3-methyl butanoic acid. Leucine catabolism was most important during the exponential phase of growth. The addition of alpha-ketoisocaproic acid at 1%, glucose at levels of 0.5% to 2% and shaking of the growth medium increased leucine catabolism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromatography, High Pressure Liquid / methods
  • Fermentation
  • Food Microbiology*
  • Glucose / pharmacology
  • Gram-Positive Asporogenous Rods / drug effects
  • Gram-Positive Asporogenous Rods / growth & development*
  • Gram-Positive Asporogenous Rods / metabolism*
  • Hydrogen-Ion Concentration
  • Keto Acids / pharmacology
  • Kinetics
  • Leucine / metabolism*
  • Odorants / analysis
  • Oxygen / pharmacology
  • Tritium

Substances

  • Keto Acids
  • Tritium
  • alpha-ketoisocaproic acid
  • Leucine
  • Glucose
  • Oxygen