Identification cloning and characterization of a branched-chain alpha-keto acid decarboxylase from Lactococcus lactis, involved in flavour formation
The biochemical pathway for formation of branched-chain aldehydes, which are important flavor compounds derived from proteins in fermented dairy products, consists of a protease, peptidases, a transaminase, and a branched-chain ¿-keto acid decarboxylase (KdcA). The activity of the latter enzyme has been found only in a limited number of Lactococcus lactis strains. By using a random mutagenesis approach, the gene encoding KdcA in L. lactis B1157 was identified. The gene for this enzyme is highly homologous to the gene annotated ipd, which encodes a putative indole pyruvate decarboxylase, in L. lactis IL1403. Strain IL1403 does not produce KdcA, which could be explained by a 270-nucleotide deletion at the 3¿ terminus of the ipd gene encoding a truncated nonfunctional decarboxylase. The kdcA gene was overexpressed in L. lactis for further characterization of the decarboxylase enzyme. Of all of the potential substrates tested, the highest activity was observed with branched-chain ¿-keto acids. Moreover, the enzyme activity was hardly affected by high salinity, and optimal activity was found at pH 6.3, indicating that the enzyme might be active under cheese ripening conditions.
Main Authors: | Smit, B.A., Meijer, L., Engels, W.J.M., Wouters, J.T.M., Smit, G. |
---|---|
Format: | Article/Letter to editor biblioteca |
Language: | English |
Subjects: | amino-acids, complete genome sequence, controlled gene-expression, enterobacter-cloacae, escherichia-coli, gram-positive bacteria, indole-3-acetic-acid biosynthesis, indolepyruvate decarboxylase, pyruvate decarboxylase, saccharomyces-cerevisiae, |
Online Access: | https://research.wur.nl/en/publications/identification-cloning-and-characterization-of-a-branched-chain-a |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Similar Items
-
Characterisation of the broad substrate specificity 2-keto acid decarboxylase Aro10p of Saccharomyces kudriavzevii and its implication in aroma development
by: Stribny, Jiri, et al.
Published: (2016-03-12) -
Identification of Lactobacillus plantarum genes that are induced in the gastrointestinal tract of mice
by: Bron, P.A., et al. -
Unraveling microbial interactions in food fermentations: from classical to genomics approaches
by: Sieuwerts, S., et al. -
Horizontal gene transfer confers fermentative metabolism in the respiratory-deficient plant trypanosomatid Phytomonas serpens.
by: IENNE, S., et al.
Published: (2012-10-22) -
Diversity of acid stress resistant variants of Listeria monocytogenes and the potential role of ribosomal protein S21 encoded by rpsU
by: Metselaar, K.I., et al.