Document Detail

Ability of thermophilic lactic acid bacteria to produce aroma compounds from amino acids.
MedLine Citation:
PMID:  15240255     Owner:  NLM     Status:  MEDLINE    
Although a large number of key odorants of Swiss-type cheese result from amino acid catabolism, the amino acid catabolic pathways in the bacteria present in these cheeses are not well known. In this study, we compared the in vitro abilities of Lactobacillus delbrueckii subsp. lactis, Lactobacillus helveticus, and Streptococcus thermophilus to produce aroma compounds from three amino acids, leucine, phenylalanine, and methionine, under mid-pH conditions of cheese ripening (pH 5.5), and we investigated the catabolic pathways used by these bacteria. In the three lactic acid bacterial species, amino acid catabolism was initiated by a transamination step, which requires the presence of an alpha-keto acid such as alpha-ketoglutarate (alpha-KG) as the amino group acceptor, and produced alpha-keto acids. Only S. thermophilus exhibited glutamate dehydrogenase activity, which produces alpha-KG from glutamate, and consequently only S. thermophilus was capable of catabolizing amino acids in the reaction medium without alpha-KG addition. In the presence of alpha-KG, lactobacilli produced much more varied aroma compounds such as acids, aldehydes, and alcohols than S. thermophilus, which mainly produced alpha-keto acids and a small amount of hydroxy acids and acids. L. helveticus mainly produced acids from phenylalanine and leucine, while L. delbrueckii subsp. lactis produced larger amounts of alcohols and/or aldehydes. Formation of aldehydes, alcohols, and acids from alpha-keto acids by L. delbrueckii subsp. lactis mainly results from the action of an alpha-keto acid decarboxylase, which produces aldehydes that are then oxidized or reduced to acids or alcohols. In contrast, the enzyme involved in the alpha-keto acid conversion to acids in L. helveticus and S. thermophilus is an alpha-keto acid dehydrogenase that produces acyl coenzymes A.
Sandra Helinck; Dominique Le Bars; Daniel Moreau; Mireille Yvon
Related Documents :
23719965 - Enhancing effect of poly(amino acid)s on albumin uptake in human lung epithelial a549 c...
19640775 - Pyridoxal 5'-phosphate: electrophilic catalyst extraordinaire.
6140755 - Absolute configuration of (-)anisodine (a new ganglio blocking agent) and (-)anisodinic...
1473985 - Eurystatins a and b, new prolyl endopeptidase inhibitors. ii. physico-chemical properti...
18662765 - Four pentacyclic triterpenoids with antifungal and antibacterial activity from curtisia...
23650915 - Paralogous chemoreceptors mediate chemotaxis towards protein amino acids and the non-pr...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Applied and environmental microbiology     Volume:  70     ISSN:  0099-2240     ISO Abbreviation:  Appl. Environ. Microbiol.     Publication Date:  2004 Jul 
Date Detail:
Created Date:  2004-07-08     Completed Date:  2004-09-16     Revised Date:  2010-09-21    
Medline Journal Info:
Nlm Unique ID:  7605801     Medline TA:  Appl Environ Microbiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  3855-61     Citation Subset:  IM    
Unité de Recherche de Biochimie et Structure des Protéines, I.N.R.A., 78352 Jouy-en-Josas, France.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Amino Acids / metabolism*
Flavoring Agents / metabolism
Glutamate Dehydrogenase / metabolism
Glutamates / metabolism
Lactobacillus / metabolism*
Leucine / metabolism
Methionine / metabolism
Phenylalanine / metabolism
Streptococcus / metabolism*
Reg. No./Substance:
0/Amino Acids; 0/Flavoring Agents; 0/Glutamates; 0/alpha-ketoglutamic acid; 61-90-5/Leucine; 63-68-3/Methionine; 63-91-2/Phenylalanine; EC Dehydrogenase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Impact of heterologous expression of Escherichia coli UDP-glucose pyrophosphorylase on trehalose and...
Next Document:  Accurate estimation of viral abundance by epifluorescence microscopy.