• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.309-315
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• 2005

In this study, the bacterial regrowth characteristics in drinking water were investigated for various nutrient concentrations and forms using improved BRP method as a traditional approach and specific regrowth rate as a new index. The results of bacterial regrowth potential for glucose and $NH_4^+-N$, which was evaluated by BRP method as a traditional index, appeared to be higher relative to that of acetate or humic acids as carbon source and $NO_2^--N\;or\;NO_3^--N$ as nitrogen sources, respectively. The results obtained by specific regrowth rate as a new index were similar to that of BRP method with respect to the nutrient conditions examined in this study; i.e., the specific regrowth rate for glucose(ranged from 0.005 to $0.082\;hr^{-1}$) was feater than that acetate and humic acids(ranged from 0.005 to $0.068\;hr^{-1}$ and from 0.005 to $0.008\;hr^{-1}$, respectively). And specific regrowth rate for $NH_4^+-N$ (ranged from 0.008 to $0.072\;hr^{-1}$) was feater than that $NO_2^--N\;and\;NO_3^--N$ (ranged from 0.008 to $0.055\;hr^{-1}$ and from 0.008 to $0.059\;hr^{-1}$, respectively). Therefore, specific regrowth rate can be applied in order to evaluate the bacterial regrowth potential in drinking water.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.1041-1048
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• 2016

Biofilm cells and viable but non-culturable (VBNC) state may play a role in the survival of Campylobacter jejuni under unfavorable environmental conditions. The objective of this study was to investigate the behavior of C. jejuni biofilm cells and VBNC cells on smoked duck. The transfer of C. jejuni biofilm cells to smoked duck and its ability to resuscitate from biofilm and VBNC cells on smoked duck was investigated. Transfer experiments were conducted from C. jejuni biofilm cells to smoked duck after 5 min, 1 h, 3 h, and 24 h contact at room temperature, and the efficiency of transfer (EOT) was calculated. In addition, smoked duck was inoculated with C. jejuni biofilm and VBNC cells and then stored at 10, 24, 36, and $42^{\circ}C$ to examine the cells' ability to resuscitate on smoked ducks. The 5 min contact time between C. jejuni biofilm cells and smoked duck showed a higher EOT (0.92) than the 24 h contact time (EOT=0.08), and the EOT decreased as contact time increased. Furthermore, C. jejuni biofilm cells on smoked duck were not recovered at 10, 24, and $36^{\circ}C$, and C. jejuni VBNC cells were not resuscitated at $42^{\circ}C$. Although the resuscitation of C. jejuni biofilm and VBNC cells was not observed on smoked duck, microbial criteria of C. jejuni is needed in poultry and processed poultry products due to risk of its survival and low infectious dose.