|
type |
Journal Article |
authors |
Fernández M, Linares DM, Alvarez MA. |
title |
Sequencing of the tyrosine decarboxylase cluster of Lactococcus lactis IPLA 655 and the development of a PCR method for detecting tyrosine decarboxylating lactic acid bacteria |
journal |
J Food Prot |
Activity |
4.1.1.25 |
Family |
4.1.1.25.a |
sel |
selected |
ui |
15553636 |
year |
(2004) |
volume |
67 |
number |
11 |
pages |
2521-9 |
| |
keywords |
Amino Acid Sequence |
abstract |
The enzymatic decarboxylation of tyrosine produces tyramine, the most abundant biogenic amine in dairy products-especially in cheeses. The screening of lactic acid bacteria isolated from different artisanal cheeses and a number of microbial collections identified 22 tyramine-producing strains belonging to different genera. The Lactococcus lactis strain IPLA 655 was selected, and the genes encoding a putative tyrosyl tRNA synthetase, a tyrosine decarboxylase (tdcA), and a tyrosine-tyramine antiporter, found together as a cluster, were sequenced. The disruption of tdcA yielded a strain unable to produce tyramine. Comparison of the L. lactis IPLA 655 tdcA gene with database tdcA sequences led to the design of two primers for use in a PCR method that identified potential tyramine-producing strains. The proposed method can use purified DNA, isolated colonies, milk, curd, and even cheese as a template. Molecular tools for the rapid detection of tyramine-producing bacteria at any time during the fermentation process could help prevent tyramine accumulation in fermented foods. The proposed technique could be of great use to the food industry. |
last changed |
2008/01/25 19:53 |
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