• 한국환경보건학회지
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• 제34권5호
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• pp.387-394
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• 2008

The toxicity of methyl tert-butyl ether (MTBE), tert-butyl alcohol (TBA) and formaldehyde (FA) on the indigenous microbial community in forest soil was studied. MTBE, TBA and FA with different concentrations were added into microcosms containing forest soil samples. After 10 and 30 days, total viable cell number and dehydrogenase activity in the microcosms were evaluated. Bacterial communities in the microcosms were also analyzed using a denaturing gradient gel electrophoresis (DGGE). Dehydrogenase activity and total viable cell number were decreased according to the increase of MTBE, TBA and FA concentrations (P<0.05). FA toxicity was the highest, but TBA toxicity was the lowest. The results of principal component analysis using DGGE fingerprints showed that the microbial communities contaminated MTBE, TBA and FA were grouped by exposure time not exposure concentration. Dominant species in the microcosms were as follows: Photobacterium damselae sub sp. and Bacillus sp. KAR28 for MTBE; Mycobacterium sp. and Uncultured Clostridium sp. for TBA; and Uncultured Paenibacillaceae bacterium and Anxynobacillus, Flavithermus for FA.

• 한국식품위생안전성학회지
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• 제11권3호
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• pp.171-176
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• 1996

Microbial distribution as well as content of salt and preservatives in side dishes was investigated by analyzing cell count of viable cells, coliform bacteria and food poisoning bacteria of sliced squid bokum and anchovy bokum, purchased at 17 different department stores and 2 different traditional market in Seoul, which are most preferred by many consumers to any other side dishes available in the market. 6.2$\times$103~1.2$\times$108 cells/g of viable cell was detected in 19 different samples of the sliced squid bokum, among which samples of the sliced squid bokum and 14 samples of the anchovy bokum contained 103~108 cells/g of coliform group. However food poisoning bacteria were not detected in all the samples tested. Salt content was 2.42~4.89 %w/w and 2.28~6.46 w/w for the sliced squid bokum and the anchovy bokum respectively. Analysis of preservatives by HPLC such as sorbic acid, benzoic acid, dehydroacetic acid and another 6 kinds of esters resulted that 1.0$\times$73.8 mg/100 g of sorbic acid was detected in the 19 samples of the sliced squid bokum, while only 6 samples of the 15 anchovy bokum samples contained sorbic acid.

• Journal of Applied Biological Chemistry
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• 제56권3호
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• pp.147-156
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• 2013

The objectives of this study were to investigate the effect of Lactobacillus paracasei subsp. tolerans JG22 isolated from pepper leaf jangajji on the mutagenic activity of N-methyl, N'-nitro, N-nitrosoguanidine (MNNG) and 2-nitrofluene (2-NF) and to evaluate the effect of physico-chemical pretreatment on the antimutagenic activity of the strain. The viable cells of JG22 strain displayed a significantly high (p <0.05) antimutagenic activity against both mutagens tested. The antimutagenic effect of JG22 strain seems to be positively correlated with the amounts of the cells in the incubation time. This strain produced the antimutagenic activity of the maximum levels after preincubation for 30 min. The binding of this strain against the mutagenic compounds might be mainly present in the cell wall fraction rather than the cytosol fraction. Pretreatment with proteolytic enzymes and simulated gastric and intestinal juices and at different pH values had no significant effect on two mutagens removal by the viable cells. However, the binding activity of the mutagen by the strain seems to be affected by heating, enzymes including $\alpha$-amylase and lysozyme, divalent ions, and sodium metaperiodate. Thus, carbohydrates consisting of the cell walls may be important elements responsible for the binding of MNNG and 2-NF by this strain. In conclusion, the binding of the mutagens to cells of JG 22 strain may play a vital role in suppressing the process of mutagenesis induced by mutagens.

• 한국수산과학회지
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• 제41권3호
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• pp.163-169
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• 2008

This study investigated the quality of salted mackerel prepared with deep seawater concentrate and salt. The quality of the salted mackerel product prepared with deep seawater was compared to that prepared with surface and intermediate seawater salts, sun-dried salt, and refined salt. After preparing the salted mackerel products using the five salts, the products were stored at $4^{\circ}C$ for 35 days. Quality characteristics compared were the acid value (AV), peroxide value (POV), lipophilic browning, volatile basic nitrogen (VBN), pH, viable cell count, and sensory factors. The deep seawater salted mackerel product had the lowest AV, POV, browning value, and viable cell counts, compared to the others, while it had the highest score in the sensory evaluation.

• 한국미생물·생명공학회지
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• 제22권4호
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• pp.436-442
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• 1994

The characteristics of activated sludge affecting the biodegradation of plastic materials under aerobic condition were studied using cellophane film as a model system. The activated sludges of site 3, which treat a mixture of domestic sewage and supernatant of septic tank, obtained from December 1993 to April 1994 showed similar biodegradation activities. Biodegradations for 28 days reached around 80%. Viable cell number of inoculums maintained at a level of 10$^{6}$~10$^{7}$ /ml. In this range, viable cell number showed no relationship with biodegradation activities. The activa- ted sludges of site 2, which treat a mixture of domestic sewage and anaerobic digest of nightsoil, obtained four times from April 1993 to April 1994 showed very different biodegradation activities ranged from 20% to 80% for 28 days. Inoculum size affects biodegradation significantly. One percent inoculum showed the best biodegradation among the inoculum sizes of 0.1, 1.0 and 10%. Ten percent inoculum revealed inhibitory effects on the biodegradation activity which can be greatly reduced by centrifugation and filtration. Filtration was better than centrifugation in reducing inhibitory effects.

• 한국식품조리과학회지
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• 제20권4호
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• pp.418-422
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• 2004

We investigated microbial populations of an upland and cultivated Codonopsis lanceolata. The microbial populations from both types of soils were also investigated. There were more than 10 microorganisms existed in upland than cultivated one. The total viable cell counts of C. lanceolata from upland and cultivated one, especially in the upper zone, were 9.7x10$\^$6/ CFU/g and 4.2${\times}$10$\^$6/ CFU/g, respectively. As a results, upper parts of C. lanceolata in upland were considered to harbour approximately more than 2.3 fold higher microorganisms than in cultivated one. However, the total viable cell counts between the two soil habitat, that is, 1.2${\times}$10$\^$7/ CFU/g from upland and 1.0x10$\^$7/ CFU/g from cultivated, were not significantly different. We also examined the unique flavor producing microorganisms in the soil extract broth including 25% C. lanceolata extract. One microorganism was detected in upper pars of C. lanceolata and upland soil. No. 6, microorganism causing the characteristic flavor of C. lanceolata was continued as Actinomyces by microscopy.

• 환경생물
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• 제28권3호
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• pp.150-157
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• 2010

자연 토양 및 Burkholderia cepacia를 접종한 멸균 토양에 PBSA film을 매립하여 PBSA의 생분해 특성을 조사하였다. 상온에서 80일간 매립 시험을 실시한 결과, 자연 토양에서는 PBSA film의 34.0%, B. cepacia를 접종한 멸균 토양에서는 59.2%의 질량 감소가 일어났으며 PBSA film의 표면 형태 변화도 B. cepacia를 접종한 멸균 토양에 매립한 경우가 자연 토양에 매립한 경우에 비하여 PBSA film 표면의 침식 및 균열이 더 빠르게 일어났다. PBSA film을 매립하였을 때 80일 후 자연 토양에서 세균수는 6~7배 증가한 반면 B. cepacia를 접종한 멸균 토양에서 개체수는 10~14배 증가하였다.

• 한국식품조리과학회지
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• 제23권2호통권98호
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• pp.252-260
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• 2007

This study was performed to provide basic data for the operation of the sous vide cook-chill system(SVCC) by comparing and evaluating the quality of SVCC prepared foods to those prepared using the cook-chill system(CC). Foremost, the microbial risk was less and the food quality excellent when SVCC was used compared to CC, where changes in pH, Aw and moisture loss were less with SVCC. The CC and SVCC Aw value were 0.93 and 0.92 and 0.92 and 0.95 at 0 days and 15 days, respectively. Secondly, the microbial quality by storage days was relatively high with SVCC. The CC and SVCC viable cell and coliform counts were 4.43 and 4.37 LogCFU/g, and 4.53 and 3.60 LogCFU/g, respectively, by 15 days. Also, after reheating, the viable cell and coliform counts satisfide the standards applied in processed food(5.0 and 2.0 LogCFU/g respectively). Lastly, the sensory scores for SVCC were higher than those for CC. Thus, microbial and sensory qualities by days of storage were acceptable and overall quality satisfaction was better for SVCC than CC.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권4호
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• pp.22-30
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• 2015

For the preliminary investigations of the bioclogging on groundwater artificial recharge system, studies for conditions and analytical methods of biofilm formation on sediments were performed. Based on the tested results, following conditions were determined for biofilm formation on batch process: optimum period for biofilm formation (30 days), the proper inoculating water (pond water), medium (minimum salt medium with 0.1% yeast extract). Procedures for the measurement of ATP and DHA were also determined. Biomass extract was used for ATP measurement, while sediment itself for DHA. Effects of metals on the biofilm formation were investigated under the determined conditions. Different sensitivities and orders were found depending on tested metals and measurement methods. In general, biomass measurement by ATP and viable cell count showed higher sensitivity than that of DHA. Following toxicity orders were also appeared for ATP and viable cell: Cu ≈ Cd > As(III).

• 한국식생활문화학회지
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• 제28권5호
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• pp.502-511
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• 2013

This study evaluated the composition two popular species of edible bamboo shoots in Korea (Phyllostachyspubescens and Sinoarundinarianigra) and the effect of their abundant dietary fiber on intestinal microorganisms in healthy young women. The ranges of total moisture, crude protein, crude lipid, crude ash, and dietary fiber content were 87.190.8, 2.943.5, 0.150.39, 0.411.05, and 4.206.15% (wet weight basis), respectively. Moisture and crude ash content increased after heat treatment; however, crude protein, crude lipid, and dietary fiber content were reduced after heating. The major minerals found in bamboo shoots were potassium, phosphorous, sulfur, magnesium, and calcium. In addition, glucose and fructose were abundant free sugars, while asparagine and tyrosine were the most abundant free amino acids. Approximately 70% of the total free fatty acids found in bamboo shoots were linoleic acid and linolenic acid. The ascorbic acid content was 6.60~17.56 mg/100 g (wet weight basis), and one phenolic compound, p-hydroxy benzoic acid, was 0.10.2% (wet weight basis) and detected by HPLC analysis. The intake of bamboo shoots for seven days significantly increased viable cell counts of Lactobacillus spp. and reduced viable cell counts of Bacteriodes spp. in feces (p<0.05). In our data, bamboo shoots may be useful in the food industry as high dietary fiber ingredients.