Predictive modelling of growth and measurement of enzymatic synthesis and activity by a cocktail of Brochothrix thermosphacta.
The possibility was examined of developing a predictive model that combined microbial growth (increase in cellular number) and extracellular enzyme activity of a cocktail of three strains of Brochothrix thermosphacta. Estimations of growth and enzyme activity were made within a three-dimensional matrix of conditions: temperature 2-20 degrees C, pH value 4.0-7.5 and water activity (a(w)) 0.95-0.995. A model which predicted growth based on increases in cell number was constructed. No extracellular lipases were detected, but slight proteolytic reactions were observed. Although it was not possible to model protease activity, the growth model and information relating to enzyme activity will be made freely available in a database on the Internet.
Institut für Lebensmittelhygiene, Leipzig University, An den Tierkliniken 1, D-04103 Leipzig, Germany. bbraun@rz.uni-leipzig.de
P
P
Braun
J P
JP
Sutherland
D015169:Colony Count, Microbial; D003470:Culture Media; D010450:Endopeptidases / Q000378:metabolism*; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D005519:Food Preservation; D016987:Gram-Positive Rods / Q000201:enzymology* / Q000254:growth & development*; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D011237:Predictive Value of Tests; D012965:Sodium Chloride / Q000494:pharmacology; D013696:Temperature; D014867:Water / Q000378:metabolism
D003470:Culture Media; D014867:Water; D012965:Sodium Chloride; D010450:Endopeptidases