Previous Article | Next Article ![]()
Applied and Environmental Microbiology, November 2004, p. 6385-6393, Vol. 70, No. 11
0099-2240/04/$08.00+0 DOI: 10.1128/AEM.70.11.6385-6393.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.
-Keto Acids by Brevibacterium linens BL2
Western Dairy Center, Center for Microbe Detection and Physiology, Department of Nutrition and Food Sciences,2 Center for Integrated BioSystems, Utah State University, Logan, Utah1
Received 18 December 2003/ Accepted 12 July 2004
Low concentrations of branched-chain fatty acids, such as isobutyric and isovaleric acids, develop during the ripening of hard cheeses and contribute to the beneficial flavor profile. Catabolism of amino acids, such as branched-chain amino acids, by bacteria via aminotransferase reactions and
-keto acids is one mechanism to generate these flavorful compounds; however, metabolism of
-keto acids to flavor-associated compounds is controversial. The objective of this study was to determine the ability of Brevibacterium linens BL2 to produce fatty acids from amino acids and
-keto acids and determine the occurrence of the likely genes in the draft genome sequence. BL2 catabolized amino acids to fatty acids only under carbohydrate starvation conditions. The primary fatty acid end products from leucine were isovaleric acid, acetic acid, and propionic acid. In contrast, logarithmic-phase cells of BL2 produced fatty acids from
-keto acids only. BL2 also converted
-keto acids to branched-chain fatty acids after carbohydrate starvation was achieved. At least 100 genes are potentially involved in five different metabolic pathways. The genome of B. linens ATCC 9174 contained these genes for production and degradation of fatty acids. These data indicate that brevibacteria have the ability to produce fatty acids from amino and
-keto acids and that carbon metabolism is important in regulating this event.
Contribution number 7589 of the Utah Agricultural Experiment Station; approved by its director.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»