Screening method for detection of immediate amino acid decarboxylases - producing bacteria implicated in food poisoning
- Author:
Husniza Hussain*
;
Mohd Fuat, A.R.
;
Vimala, B.
;
Ghazali, H.M.
- Publication Type:Journal Article
- From:Tropical Biomedicine
2011;28(2):351-361
- CountryMalaysia
- Language:English
-
Abstract:
Assessment of amino acid decarboxylase activity can be conducted using tubed
broth or plated agar. In this study, the test was carried out in microtitre plates containing
lysine, ornithine, arginine, tyrosine, tryptophan, phenylalanine or histidine as biogenic amine
precursors. Møller decarboxylase base broth (MDB) with or without 1% of a known amino acid
were added to wells of a 96 well-microtitre plate. The wells were inoculated with Escherichia
coli, Klebsiella pneumoniae, Acinetobacter anitratus or Staphylococcus aureus to the final
concentration of 6.0 x 107 cfu/ml and incubated at 35oC. The absorbance of the culture broth
was read at 570 nm at 0, 1.0, 2.0, 3.0, 4.0, 5.5, 6.5 and 7.5 hour. Comparison of means of A’570
between 0 hour and a specified incubation time was determined statistically. Positive
decarboxylase activities were detected in the media inoculated with E. coli and K. pneumoniae
in less than 6 hours. The current method is suitable for immediate producers of amino acid
decarboxylase enzymes. It costs less as it uses less amino acid and it has the potential to be
used for screening aliquots of food materials for amino acid decarboxylase activities.
- Full text:W020150615374667936365.pdf
