TY - JOUR
T1 - Decarboxylase gene expression and cadaverine and putrescine production by Serratia proteamaculans in vitro and in beef
AU - De Filippis, Francesca
AU - Pennacchia, Carmela
AU - Di Pasqua, Rosangela
AU - Fiore, Alberto
AU - Fogliano, Vincenzo
AU - Villani, Francesco
AU - Ercolini, Danilo
PY - 2013/8/1
Y1 - 2013/8/1
N2 - Studies of the molecular basis of
microbial metabolic activities that are important for the changes in
food quality are valuable in order to help in understanding the behavior
of spoiling bacteria in food.The growth of a psychrotrophic Serratia proteamaculans strain was monitored in vitro and in artificially inoculated raw beef. Two growth temperatures (25 °C and 4 °C) were tested in vitro, while growth at 15 °C and 4 °C
was monitored in beef. During growth, the expression of inducible
lysine and ornithine-decarboxylase genes was evaluated by quantitative
reverse transcription-PCR (qRT-PCR), while the presence of cadaverine
and putrescine was quantified by LC-ESI–MS/MS. The expression of the
decarboxylase genes, and the consequent production of cadaverine and
putrescine were shown to be influenced by the temperature, as well as by
the complexity of the growth medium. Generally, the maximum gene
expression and amine production took place during the exponential and
early stationary phase, respectively. In addition, lower temperatures
caused slower growth and gene downregulation. Higher amounts of
cadaverine compared to putrescine were found during growth in beef with
the highest concentrations corresponding to microbial loads of ca. 9 CFU/g. The differences found in gene expression evaluated in vitro and in beef suggested that such activities are more reliably investigated in situ in specific food matrices.
AB - Studies of the molecular basis of
microbial metabolic activities that are important for the changes in
food quality are valuable in order to help in understanding the behavior
of spoiling bacteria in food.The growth of a psychrotrophic Serratia proteamaculans strain was monitored in vitro and in artificially inoculated raw beef. Two growth temperatures (25 °C and 4 °C) were tested in vitro, while growth at 15 °C and 4 °C
was monitored in beef. During growth, the expression of inducible
lysine and ornithine-decarboxylase genes was evaluated by quantitative
reverse transcription-PCR (qRT-PCR), while the presence of cadaverine
and putrescine was quantified by LC-ESI–MS/MS. The expression of the
decarboxylase genes, and the consequent production of cadaverine and
putrescine were shown to be influenced by the temperature, as well as by
the complexity of the growth medium. Generally, the maximum gene
expression and amine production took place during the exponential and
early stationary phase, respectively. In addition, lower temperatures
caused slower growth and gene downregulation. Higher amounts of
cadaverine compared to putrescine were found during growth in beef with
the highest concentrations corresponding to microbial loads of ca. 9 CFU/g. The differences found in gene expression evaluated in vitro and in beef suggested that such activities are more reliably investigated in situ in specific food matrices.
U2 - 10.1016/j.ijfoodmicro.2013.05.021
DO - 10.1016/j.ijfoodmicro.2013.05.021
M3 - Article
VL - 165
SP - 332
EP - 338
JO - International Journal of Food Microbiology
JF - International Journal of Food Microbiology
SN - 0168-1605
IS - 3
ER -