Diversity of L-methionine catabolism pathways in cheese-ripening bacteria.

Pascal Bonnarme , Lefki Psoni and Henry E . Spinnler Pathways in Cheese - Ripening Bacteria Diversity of l - Methionine Catabolism

Evidence for distinct L-methionine catabolic pathways in the yeast Geotrichum candidum and the bacterium Brevibacterium linens.

Tracing experiments were carried out to identify volatile and nonvolatile L-methionine degradation intermediates and end products in the yeast Geotrichum candidum and in the bacterium Brevibacterium linens, both of which are present in the surface flora of certain soft cheeses and contribute to the ripening reactions. Since the acid-sensitive bacterium B. linens is known to produce larger amoun...

Gene expression and biochemical analysis of cheese-ripening yeasts: focus on catabolism of L-methionine, lactate, and lactose.

DNA microarrays of 86 genes from the yeasts Debaryomyces hansenii, Kluyveromyces marxianus, and Yarrowia lipolytica were developed to determine which genes were expressed in a medium mimicking a cheese-ripening environment. These genes were selected for potential involvement in lactose/lactate catabolism and the biosynthesis of sulfur-flavored compounds. Hybridization conditions to follow speci...

Tyrosine and phenylalanine catabolism by Lactobacillus cheese flavor adjuncts.

Bacterial metabolism of Tyr and Phe has been associated with the formation of aromatic compounds that impart barny-utensil and floral off-flavors in cheese. In an effort to identify possible mechanisms for the origin of these compounds in Cheddar cheese, we investigated Tyr and Phe catabolism by Lactobacillus casei and Lactobacillus helveticus cheese flavor adjuncts under simulated Cheddar chee...

Fate of Listeria monocytogenes during Ripening of Iranian Traditional Koozeh Cheese Made from Raw Ewe\'s Milk

Background: One of the most well-known Iranian traditional cheeses is Koozeh. The aim of present work was to evaluate the survival of L. monocytogenes during ripening of Iranian traditional Koozeh cheese made from raw ewe's milk. Methods: A 2-factor experimental design was applied to study the effect of ripening conditions, including different temperatures (4, 9, and 14 °C) and different conce...