Peer-Reviewed Journal Details
Mandatory Fields
Curtin, AC,De Angelis, M,Cipriani, M,Corbo, MR,McSweeney, PLH,Gobbetti, M;
2001
January
Journal of Applied Microbiology
Amino acid catabolism in cheese-related bacteria: selection and study of the effects of pH, temperature and NaCl by quadratic response surface methodology
Validated
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Optional Fields
CYSTATHIONINE GAMMA-LYASE LACTOCOCCUS-LACTIS SUBSP BETA-LYASE PURIFICATION METHIONINE PROTEIN CLONING
91
312
321
Aims: To screen the cystathionine lyase and L-methionine aminotransferase activities of cheese-related bacteria (lactococci, non-starter lactobacilli and smear bacteria) and to determine the individual and interactive effects of temperature, pH and NaCl concentration on selected enzyme activities.Methods and Results: A subcellular fractionation protocol and specific enzyme assays were used, and a quadratic response surface methodology was applied. The majority of the strains, 21 of 33, had detectable cystathionine lyase activity which differed in the specificity. Aminotransferase activity on L-methionine was observed in only three strains. The cystathionine lyase activities of Lactobacillus reuteri DSM20016, Lactococcus lactis subsp. cremoris MG1363, Brevibacterium linens 10 and Corynebacterium ammoniagenes 8 and the L-methionine aminotransferase activity, of Lact. reuteri DSM20016 had temperature and pH optima of 30-45 degreesC, and 7.5-8.0, respectively. As shown by the quadratic response surface methodology these enzymes retained activities in the range of temperature, pH and NaCl concentration which characterized the cheeses from which the bacteria originated.Conclusions: The enzyme activities may have a role in flavour development during cheese ripening.Significance and Impact of the Study: The findings of this work contribute to the knowledge about the amino acid catabolic enzymes in order to improve cheese ripening.
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