• 한국축산식품학회지
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• 제29권1호
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• pp.47-54
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• 2009

Predictive modeling was applied to study the growth of microorganisms related to spoilage in frankfurter sausage containing various levels of dietary fiber (0, 1, 2, and 3%) from rice bran and to estimate its shelf-life. Using the Baranyi model, total viable cells, anaerobic and psychrotrophic bacteria were measured during 35 days of cold storage ($<4{\pm}1^{\circ}C$). The lag times (LT) demonstrated by control and treatment groups were 6.28, 623, 6.24, and 6.25 days, respectively. The growth rate of total viable cells in each group were 0.95, 0.91, 0.92, and 0.91 (Log CFU/g/day), respectively. The anaerobic and psychrotrophic bacteria had lower initial ($y_0$) and maximal bacterial counts ($y_{max}$) than total viable cells. Also, the anaerobic and psychrotrophic bacteria possessed lower growth rate and longer lag time than total viable cells. The estimated shelf-life of frankfurter containing rice bran fiber by the growth rate of total viable cells was 7.8, 7.9, 7.9, and 7.7 days, respectively. There were no significant differences in shelf-life as a function of fiber content. In other words, the addition of dietary fiber in sausage did not show the critically hazardous results in growth of microorganism. The 12 predictive models were then characterized by high $R^2$, and small RMSE. Furthermore, $B_f$ and $A_f$ values showed a very close relationship between the predictive and observed data.

• 한국동물위생학회지
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• 제15권2호
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• pp.215-225
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• 1992

To estimate pollution status of livestock wastewater on four piggeries and one abattoir in Taegu area, physicochemical water analysis such as pH, suspended solid(SS), biochemical oxygen demand(BOD) and chemical oxygen demand(COD), and bacteriological examinations such as number of total viable cells and number of coliform with or without antibiotic resistance were carried out. The results obtained were as follows : The pH values of raw sewage ranged from 9.0 to 7.2 that of the effluent treated was lowed to 5.6~7.7. The SS values of raw sewage ranged from 5,275ppm to 120ppm and those of the efflunet decreased to 162~30ppm. The BOD values of raw sewage ranged 6,200ppm to 120ppm and those of the effluent treated decreased to 111 ~80ppm. The COD values of raw sewage ranged from 5,725ppm to 298ppm and those of the effluent decreased to 137~76ppm. The total viable cells of raw sewage ranged from $8.5{\times}11^{11}$/ml to $9.9{\times}10^7$/ml, those of the effluent decreased to $5.6{\times}10^6{\sim}4.2{\times}10^8/ml.$ The total coliforms of raw sewage ranged from $5.5{\times}10^9$/ml to $1.3{\times}10^5$/ml, those of the effluent decreased to $3.6{\times}10^4ml{\sim}9.0{\times}10^6$/ml. The incidence of streptomycin resistant coliforms was the highest(1.8~66.7%), and followed by tetracycline(1.7~64%), kanamycin(9.3~50.l%), ampicillin(0.06~45.5%) and chloramphenicol(14.3~33.5%) to total coliforms of raw sewage. The incidence of antibiotic resistant coliforms of raw sewage in farms ranged from 3.4~66.7% and that of abattoir's was 0.06% to 14.3%. Antibiotic resistant coliform counts of raw sewage ranged from 1.3$\times$10$^{8}$ /ml to 3.9$\times$10$^3$/ml, those of the effluent decreased to $3.0{\times}10^1{\sim}2.3{\times}10^5/ml$.

• 한국식품위생안전성학회지
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• 제38권1호
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• pp.19-25
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• 2023

비가열 닭고기 분쇄육의 제조 시 향신료의 첨가에 의한 세균의 증식 억제 효과에 대하여 연구하였다. 닭가슴살 분쇄육의 일반성분은 수분 72.98±0.15%, 조단백질 23.37±0.46%, 조지방 1.00±0.03%, 조회분 1.90±0.03%였다. 향신료 첨가에 의한 미생물 증식 억제 효과는 로즈마리 > 마늘 > 겨자 순이었으며, 첨가량이 증가할수록 억제 효과가 커졌다. 닭고기 분쇄육의 일반세균 및 대장균 증식 억제를 나타내는 향신료의 최적 첨가 농도는 로즈마리 2%, 마늘 4%, 겨자 1.2%였다. 일반세균 및 대장균에 대한 증식 억제 효과는 단독 및 혼합 첨가 시 저장기간 동안 기간별로 차이가 있었고, 저장 9일째 억제 효과는 MixA(97.4%) > 로즈마리(96.9%) > MixB(96.3%) > 마늘(53.7%) > 겨자(33.3%) 순이었다. 닭고기 분쇄육에 살균마늘과 비살균마늘을 첨가하여 비교했을 때 일반세균 수는 살균마늘 처리구가 비살균마늘 처리구에 비해 초기 2.6-3.0 log CFU/g, 9일째 2.4-3.2 log CFU/g 정도 낮았고, 저장기간이 경과할수록 그 수가 감소하였다. 비살균마늘 처리구는 대조구보다 높은 일반세균 수를 나타냈으며, 저장기간이 경과할수록 증가하는 경향을 나타냈다. 대장균 수의 경우 살균마늘 처리구가 비살균마늘 처리구에 비해 저장 0일째 0.4-1.0 log CFU/g, 9일째 0.5-1.5 log CFU/g 정도 낮았으며, 저장기간의 경과에 따른 변화는 일반세균 수와 비슷한 경향을 나타냈다. 결론적으로 로즈마리, 마늘, 겨자의 다양한 혼합적용에 의해 닭고기 분쇄육 제품의 미생물적 안전성이 향상되었다.

• The Plant Pathology Journal
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• 제29권4호
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• pp.374-385
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• 2013

Environmental stresses induce several plant pathogenic bacteria into a viable but nonculturable (VBNC) state, but the basis for VBNC is largely uncharacterized. We investigated the physiology and morphology of the copper-induced VBNC state in the plant pathogen Ralstonia solanacearum in liquid microcosm. Supplementation of $200{\mu}M$ copper sulfate to the liquid microcosm completely suppressed bacterial colony formation on culture media; however, LIVE/DEAD BacLight bacterial viability staining showed that the bacterial cells maintained viability, and that the viable cells contain higher level of DNA. Based on electron microscopic observations, the bacterial cells in the VBNC state were unchanged in size, but heavily aggregated and surrounded by an unknown extracellular material. Cellular ribosome contents, however, were less, resulting in a reduction of the total RNA in VBNC cells. Proteome comparison and reverse transcription PCR analysis showed that the Dps protein production was up-regulated at the transcriptional level and that 2 catalases/peroxidases were present at lower level in VBNC cells. Cell aggregation and elevated levels of Dps protein are typical oxidative stress responses. $H_2O_2$ levels also increased in VBNC cells, which could result if catalase/peroxidase levels are reduced. Some of phenotypic changes in VBNC cells of R. solanacearum could be an oxidative stress response due to $H_2O_2$ accumulation. This report is the first of the distinct phenotypic changes in cells of R. solanacearum in the VBNC state.

• 한국식품영양학회지
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• 제21권2호
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• pp.176-183
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• 2008

This study examined the anti-microbiological effects of chlorine treatment on the surface of fresh fruits, in order to improve microbiological safety in school foodservice operations. Non-peeled fruit(strawberries) and peeled fruit(bananas) were treated with different concentrations of chlorinated water and rinsing numbers, followed by microbiological testing. The fruits were immersed at different concentrations of chlorinated water(0 ppm, 50 ppm, and 100 ppm) and durations(3 min and 5 min), and were then rinsed with tap water(one time, two times, or three times). The total viable cell counts of both the strawberries and bananas ranged from $10^3$ CFU/g to $10^4$ CFU/g, and coliform levels ranged from $10^2$ CFU/g to $10^3$ CFU/g. As the chlorine concentration, immersion time, and rinsing number increased, anti-microbiological activity increased. The largest microbial reduction was shown with immersion for 5 min in 100 ppm chlorinated water and three rinsings. In the strawberries, this treatment reduced the initial population of total viable cells and coliforms by 3.29 log CFU/g and to an undetectable level, respectively, no total viable cells or coliforms were detected on the banana surface following this treatment. However, after a sterilization treatment with immersion for 5 min in 50 ppm chlorinated water and three rinsings, the total viable cell counts and coliform counts of the strawberries and bananas decreased to acceptable levels, based on the microbiological standards for ready-to-eat foods. Overall, it was shown that the sterilization treatment of 50 ppm chlorinated water, soaking for 5 min, and three rinsings provided an effective reduction in surface microbes, and enhanced the microbiological safety of the fruit.

• 한국식품위생안전성학회지
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• 제1권1호
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• pp.47-50
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• 1986

Sanitary condition for raw milk in Korea was investigated in this study. It is hoped that the information will be used for reference in future endeavors of study in the field of public health and food sanitation in Korea. The results were summerized as follows: 1) The viable cell counts of bacteria in raw milk were tend to be increased under the various atmospheric temperature, and the correlation coefficient between temperature and total viable cells was r=+0.921(p<0.01). 2) The correlation coefficient between methylene blue reduction time test and viable cell counts of bacteria in raw milk was r=-0.799(p<0.01). 3) The relationship between total solid rate(%) and milk fat rate(%) was highly significant level as r=+0.745(p<0.01). 4) Highly significant correlation coefficient was r= +0.945(p<0.01) between milk fat and protein rate in raw milk.

• 미생물학회지
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• 제52권3호
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• pp.313-318
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• 2016

Viable but nonculturable (VBNC) 상태에 들어간 세균은 일반적인 증균 배지에서는 집락을 형성하지 않지만, 죽은 것이 아니라 낮은 대사활성상태로 유지되고 있다. 본 연구에서는 $10^{\circ}C$의 저온 빈영양 해수에서 Edwardsiella tarda를 VBNC 상태로 유도한 후, 해수 온도를 10에서 $25^{\circ}C$로 상승시킬 때 첨가된 유기물의 종류에 따라 VBNC 상태인 균의 소생 가능성을 알아보고자 하였다. E. tarda가 접종된 빈영양 해수 microcosm을 $10^{\circ}C$에 유지하였을 때 VBNC 유도 기간은 42-84일까지 다양하였다. 유도 기간 동안 acridine orange direct counting법으로 계수한 총 균수는 초기 접종 농도인 약 $10^8cells/ml$로 일정하였으며, direct viable counting법으로 계수한 생존 균수는 약 $10^4cells/ml$로 감소되었다. VBNC E. tarda에 효모추출물, 넙치근육추출물 그리고 혈청을 첨가하여 $25^{\circ}C$에서 소생을 유도한 결과 전체 시료 개수의 37%, 23%, 37%에서 각각 소생이 확인되었으며 소생된 E. tarda의 특성은 VBNC 유도 전 원래의 세균과 일치하였다. 소생된 E. tarda를 넙치(Paralichthys olivaceus)에 복강 주사 하였을 때 접종 후 5일 이내에 시험어가 모두 사망함으로써 VBNC 상태의 E. tarda가 독력을 유지하고 있었음을 시사하였다. 그러므로 E. tarda는 우리나라 남해 연안 겨울의 저온 빈영양 해수에서 VBNC 상태로 유도되었다가 여름과 가을 시기에 수온 상승과 더불어 소생되어 양식 넙치에 지속적인 발병 요인이 되고 있는 것으로 생각된다.

• International Journal of Oral Biology
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• 제35권1호
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• pp.1-5
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• 2010

Human fibroblasts that maintain the structural integrity of connective tissues by secreting precursors of the extracellular matrix are typically cultured with serum. However, there are potential disadvantages of the use of serum including unnatural interactions between the cells and the potential for exposure to animal pathogens. To prevent the possible influence of serum on fibroblast cultures, we devised a serum-free growth method and present in vitro data that demonstrate its suitability for growing porcine fetal fibroblasts. These cells were grown under four different culture conditions: no serum (negative control), 10% fetal bovine serum (FBS, positive control), 10% knockout serum replacement (KSR) and 20% KSR in the medium. The proliferation rates and viabilities of the cells were investigated by counting the number of cells and trypan blue staining, respectively. The 10% FBS group showed the largest increase in the total number of cells ($1.09\;{\times}\;10^5\;cells/ml$). In terms of the rate of viable cells, the results from the KSR supplementation groups (20% KSR:64.7%; 10% KSR: 80.6%) were similar to those from the 10% FBS group (68.5%). Moreover, supplementation with either 10% ($3.0\;{\times}\;10^4\;cells/ml$) or 20% KSR ($4.8\;{\times}\;10^4\;cells/ml$) produced similar cell growth rates. In conclusion, although KSR supplementation produces a lower cell proliferation rate than FBS, this growth condition is more effective for obtaining an appropriate number of viable porcine fetal fibroblasts in culture. Using KSR in fibroblast culture medium is thus a viable alternative to FBS.

• 동아시아식생활학회지
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• 제14권2호
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• pp.131-134
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• 2004

This study was carried out to investigate the shelf life of Shepherd's purse(Capsella bursa-pastoris) Kimchi during fermentation at 1$0^{\circ}C$. Capsella bursa-pastoris was treated without or with blanching. The viable cells of lactic acid bacteria(LAB) of raw and blanched Kimchi after fermentation for 15 days at 1$0^{\circ}C$ were 7.91 log CFU/mL and 6.4 log CFU/mL, respectively. The viable cells of LAB of Capsella bursa-pastoris Kimchi at 1$0^{\circ}C$ were lower in the blanched one when compared to the raw one. The pH of raw Kimchi was lower than that of the blanched one during fermentation for 25 days at 1$0^{\circ}C$. The viable cells of total bacteria of the blanched Kimchi were lower than that of non-blanched one during fermentation at 1$0^{\circ}C$. The ascorbic acid and chlorophyll contents decreased more in the blanched Kimchi when compared to that treated without heat. The sensory quality of the blanched Kimchi was a little inferior to that treated without heat during fermentation.

• 한국식품조리과학회지
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• 제20권6호
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• pp.561-567
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• 2004

The purpose of this study was to investigate the effect of Paecilomyces japonica mycelia(PJM) on pH, titrable acidity and microbiological qualify of Jeungpyun(fermented rice cake). Jeungpyun prepared with $0\~\%$ of PJM stored at $5^{\circ}C\;and\;20^{\circ}C$ for 4 weeks and 7 days respectively. Before fermentation of Jeungpyun dough, viable cells of total bacterial counts(TBC), yeasts and lactic acid bacteria(LAB) were $6.0\~9.8\times10^6,\;5.3\~9.0\times10^6,\;5.4\~8.5\times10^6\;CFU/g$, respectively. During the fermentation of dough, viable cells of TBC, yeasts and LAB increased $0.3\~0.4$ log cycle and pH was decreased whereas acidity increased as the progress of fermentation. Total viable cells in Jeungpyun before storage were $5.0\times10^1\;CFU/g$. During storage of Jeungpyun, TBC, yeasts and LAB of control group increased 2.6, 2.4, 2.1 log cycle at $5^{\circ}C$ and 4.8, 4.6, 4.5 log cycle at $50^{\circ}C$, respectively, when reached at maximum level. Major microflora of Jeungpyun was composed of yeasts and LAB during fermentation of dough and storage at $5^{\circ}C\;and\;20^{\circ}C$. Addition of PJM, inhibited the growth of microorganisms, the changes of PH and titrable acidity of Jeungpyun during storage at both of $5^{\circ}C\;and\;20^{\circ}C$. From these results, the addition of PJM extended the shelf-life of Jeungpyun during storage at $5^{\circ}C\;and\;20^{\circ}C$.