RRC ID 48241
Author Udomsil N, Chen S, Rodtong S, Yongsawatdigul J.
Title Quantification of viable bacterial starter cultures of Virgibacillus sp. and Tetragenococcus halophilus in fish sauce fermentation by real-time quantitative PCR.
Journal Food Microbiol
Abstract Real-time quantitative polymerase chain reaction (qPCR) methods were developed for the quantification of Virgibacillus sp. SK37 and Tetragenococcus halophilus MS33, which were added as starter cultures in fish sauce fermentation. The PCR assays were coupled with propidium monoazide (PMA) treatment of samples to selectively quantify viable cells and integrated with exogenous recombinant Escherichia coli cells to control variabilities in analysis procedures. The qPCR methods showed species-specificity for both Virgibacillus halodenitrificans and T. halophilus as evaluated using 6 reference strains and 28 strains of bacteria isolated from fish sauce fermentation. The qPCR efficiencies were 101.1% for V. halodenitrificans and 90.2% for T. halophilus. The quantification limits of the assays were 10(3) CFU/mL and 10(2) CFU/mL in fish sauce samples with linear correlations over 4 Logs for V. halodenitrificans and T. halophilus, respectively. The matrix effect was not observed when evaluated using fish sauce samples fermented for 1-6 months. The developed PMA-qPCR methods were successfully applied to monitor changes of Virgibacillus sp. SK37 and T. halophilus MS33 in a mackerel fish sauce fermentation model where culture-dependent techniques failed to quantify the starter cultures. The results demonstrated the usability of the methods as practical tools for monitoring the starter cultures in fish sauce fermentation.
Volume 57
Pages 54-62
Published 2016-8-1
DOI 10.1016/j.fm.2016.01.004
PII S0740-0020(16)00005-8
PMID 27052702
MeSH Animals Enterococcaceae / genetics Enterococcaceae / metabolism* Fermentation Fish Products / microbiology* Fishes Real-Time Polymerase Chain Reaction / methods* Virgibacillus / genetics Virgibacillus / metabolism*
IF 4.155
Times Cited 12
WOS Category BIOTECHNOLOGY & APPLIED MICROBIOLOGY FOOD SCIENCE & TECHNOLOGY MICROBIOLOGY
Resource
General Microbes JCM 10006 JCM 6074 JCM 6057