• Korean Journal of Hydrosciences
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• 제2권
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• pp.115-126
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• 1991

The anaerobic digester with sludge from sewage treatment plant was operated in the laboratory for two year to investigate the enumeration and activity of methanogenic microorganisms. In this experimental study, the effects of HRT on the degradation characteristics of organic materials and on the number of methanogenic bacteria produced were investigated. By making the media with the repeated wxperiment, the number and activity of methanogenic bacteria were measured. The increase of the removal rate of organic acid in the digester was oberved at HRT of 2 days. The total number of methane forming bacteria estimated by the MPN method showed 2.3 $\times$ $ at HRT of 3 days, 7$\times$$ of 5 days and 7.9$\times$$ $/ml of 10 days. The optimum incubation time for measuring the number of methanogenic bacteria was found as more than four weeks. The PMA revealed 161ml CH$/l day at HRT of 10 days and the PUA 290mg COD/l day. At the incubation time 4.3 days, the maximum value of CH$ *59.1%) was found. At this time, $ was found as 15.3% and $ 25.6%.

• 한국식품영양학회지
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• 제3권2호
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• pp.141-148
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• 1990

This studies were carried out to investigate the effects of non-volatile organic acids in the KimChi by lactic acid bacteria. The organism isolated from KimChi, Pediococcus dextrinicus, Leuconostoc mesenteroides, Lactobacillus plantarum and Lactobacillus brevis, were inoculated for preparation of KimChi. pH of all on the KimChi sample dropped sharply according as fermentation continued. pH of on optimum ripening period KimChi(4.4 and 4.2) reached 1.3 and 1.9 day at all on sample, respectively. Optimum acidity(0.5%) of KimChi were reached within 2 day all on sample. The total number of lactic acid bacteria reached 1.0X107cells/ml in 1 day and decreased slowly after 4 day. Main non-volatile organic acids were identified lactic, malic and succinic acid. The sensory score of mixed lactic acid bacteria inoculated KimChi was better than that of another KimChi.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2005년도 제36차 추계 학술발표대회
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• pp.319-323
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• 2005

Lactic acid bacteria are dominant microflora in many kinds of fermented foods. In this study, dominant microflora, especially lactic acid bacteria were isolated from salted sea food, and we determined physiological characteristics, and assayed specific property such as bacteriocin activity. The population of lactic acid bacteria as well as aerobic mesophilic counts was at the level of $10^7$ cfu /g. Total 17 strains of LAB were isolated from salted sea food sample. The phenotypic characteristics of these strains were determined followed by Bergey's Manual. And genotypic and bacteriocin activity were tested by Schillinger and $L{\ddot{u}}cke^{(7)}$.

• 한국식품영양학회지
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• 제7권1호
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• pp.45-50
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• 1994

This study was carried out to Investigate the effects of Panax ginseng, Ganoderma lucidum extract and crude polysaccharide of G. lucidum on the growth of lactic acid bacteria. p. ginseng extract contained 60.7% carbohydrate and 27.5% protein, whereas G. lucidum contained 35.9% carbohydrate and 46.3% protein. The total sugar and protein content of crude polysaccharide of G. lucidum were 47.2% and 15.2%, respectively. Two amino acids(hg, Trp) were detected in p. ginseng extract and 11 amino acids (hg, Trp, Ua, Lys, Ser, etc.) in C. lucidum extract. By the addition of p. ginseng, 5. lucidum extract and crude polysaccharide, the cia. p. ginseng was more effective on the growth of 1. casei an: G. lucidum was more effective on that of S. thermophilus. The effect of free amino acids on the growth of tactic acid bacteria was also examined. Arginine and lysine stimulated the growth of L. casei, whereas Lysine, serine, arginine, and glutamic acid stimulated the growth of 5. thermophilus.

• 약학회지
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• 제30권1호
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• pp.8-13
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• 1986

It has been assumed that nitrite, one of the precursor of N-nitrosamine, in human saliva must have been formed from salivary nitrate through the action of microorganism in the oral cavity. In this paper, we have tested the concentration of nitrite and nitrate in human saliva and the degrees of nitrate reduction by oral microflora and identified some bacteria which were able to reduce nitrate. The concentration of nitrite and nitrate was 1.7~9.5ppm and 9.0~28.5ppm respectively. The numbers of total bacteria and nitrate reducing bacteria in four korean human saliva sample were 15~63${\times}10^8$ CFU and 1.0~6.0${\times}10^8$ CFU and the main nitrate reducing bacteria were Streptococcus uberis which was presented in large quantities and showed remarkable reductive activity. Lastly, we knowed that N-dimethylnitrosamine was formed by the reaction between dimethylamine and nitrite in the presence of St. uberis in vitro.

• Journal of Microbiology and Biotechnology
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• 제30권10호
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• pp.1516-1524
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• 2020

Climate change is expected to affect not only availability and quality of water, the valuable resource of human life on Earth, but also ultimately public health issue. A six-year monitoring (total 20 times) of Escherichia coli O157, Salmonella enterica, Legionella pneumophila, Shigella sonnei, Campylobacter jejuni, and Vibrio cholerae was conducted at five raw water sampling sites including two lakes, Hyundo region (Geum River) and two locations near Water Intake Plants of Han River (Guui region) and Nakdong River (Moolgeum region). A total 100 samples of 40 L water were tested. Most of the targeted bacteria were found in 77% of the samples and at least one of the target bacteria was detected (65%). Among all the detected bacteria, E. coli O157 were the most prevalent with a detection frequency of 22%, while S. sonnei was the least prevalent with a detection frequency of 2%. Nearly all the bacteria (except for S. sonnei) were present in samples from Lake Soyang, Lake Juam, and the Moolgeum region in Nakdong River, while C. jejuni was detected in those from the Guui region in Han River. During the six-year sampling period, individual targeted noxious bacteria in water samples exhibited seasonal patterns in their occurrence that were different from the indicator bacteria levels in the water samples. The fact that they were detected in the five Korea's representative water environments make it necessary to establish the chemical and biological analysis for noxious bacteria and sophisticated management systems in response to climate change.

• 한국식품과학회지
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• 제34권5호
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• pp.927-930
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• 2002

시금치를 한국 식단의 식자재로 사용하기 위해 cook-chill 가공과 sous vide 기술을 사용하였다. 시금치는 500 g 단위로 차단성 필름을 사용하여 진공포장하고 Listeria monocytogenes의 6D 사멸조건에서 저온살균하고 $3^{\circ}C$에서 급속히 냉각한 다음 $3^{\circ}C$와 $10^{\circ}C$에서 저장하면서 품질을 측정하였다. 오염지표균은 중온성세균, 저온성세균, 혐기성세균, 내열성세균, 대장균군, 효모 및 곰팡이, Enterobacteriacea 및 분원성연쇄상구균을 측정하였다. 원료 시금치에서는 $2.2{\times}10^8\;cfu/g$로 높은 분포를 보였고, cook-chill 가공 후에는 $6.0{\times}10^3\;cfu/g$로 감소하였으며 저장기간 동안 서서히 증가하였다. 저온성세균과 혐기성세균은 거의 같은 양상을 보였으며, 효모 및 곰팡이, 대장균군, 분원성연쇄상구균 및 Enterobacteriacea는 cook-chill 가공 후에는 검출되지 않았다. 그람음성의 병원성세균은 Aeromonas hydrophila, Escherichia coli O157:H7, Plesiomonas shigelloides, Pseudomonas aeruginosa, Salmonella spp., Shigella spp., Yersinia enterocolitica, 그람양성균은 Bacillus cereus, Campylococcus spp., Clostridium perfringens, Listeria monocytogenes, Staphylococcus aureus을 분리시험하였다. A. hydrophila는 수세한 시금치에서 분리되었으나, 원료 시금치와 cook-chill한 시금치에서는 분리되지 않았다. B. cereus와 C. perfringens는 원료 시금치, 수세한 시금치와 cook-chill 가공한 시금치에서 분리된 반면 S. aureus는 원료 시금치와 수세한 시금치에서만 분리되었다. 그 외의 다른 병원성세균은 cook-chill 과정에서 분리되지 않았다.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1990년도 Proceedings of International Symposium on Korean Ginseng, 1990, Seoul, Korea
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• pp.111-122
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• 1990

The growth responses of a variety of human Intestinal bacteria to extracts of Pun(1.vKy'n.ieny and five other oriental medicinal Araliaceae were evaluated in vitro and in vivo. The extracts enhanced the growth of Bifidobncterilim breve and B. longum in Media with or without carbon sources, suggesting the bifid factor (5) might be involved in the phenomenon. This effect was most pronounced with water extract of p. ginseng, the growth of 27 bifidobacteria strains belonging to B. ndolexcentium, H. longlrm, and 1. breve and B. iniuntis being greatly stimurated, whereas seven B. bifidum strains and other bacteria such as clostridia and 5.fcherirhia coli had little or no ability to utilizes it (or growth. Methanol extracts of p, ginseng were found to selectively inhibit growth of various clostridia including C. perfringens and C. Paraputrificum, but this effect was not observed on other bacteria including bifidobacteria. The effect of ginseng extract intake(600 mg/day for two weeks) on the fecal microflora, pH, volatile fatty acids, ammonia, putrefactive products, and -glucuronidase, -glucosidase and nitroreductase activities, and on the blood components (triglyceride, total cholesterol and ammonia) were investigated using seven healthy human volunteers. The total concentration of fecal microflora including Bri'idobucterilim app. during the period of ginseng extract intake was significantly unaffected from the proceeding and sub sequent control periods. However, the frequency of occurrence of subjects having C. perfringens was significantly decreased. The fecal pH value was also significantly decreased, suggesting that the intake might increase the activity of Bifidobacterium spp. Other biochemical properties in faces did not changed significantly. The levels of ammonia and triglycerid in blood were decreased with ginseng extract intake. These results may be an indication of at least one of the pharmacological actions of P ginseng as an adaptogen.

• Asian-Australasian Journal of Animal Sciences
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• 제27권2호
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• pp.179-186
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• 2014

This study aimed to investigate the diversity of the Butyrivibrio group bacteria in goat rumen and its response to garlic oil (GO) supplementation as revealed by molecular analysis of cloned 16S rRNA genes. Six wethers fitted with ruminal fistulas were assigned to two groups for a cross-over design with 28-d experimental period and 14-d interval. Goats were fed a basal diet without (control) or with GO ruminal infusion (0.8 g/d). Ruminal contents were used for DNA extraction collected before morning feeding on d 28. A total bacterial clone library was firstly constructed by nearly full-length 16S rRNA gene cloned sequences using universal primers. The resulting plasmids selected by Butyrivibrio-specific primers were used to construct a Butyrivibrio group-specific bacterial clone library. Butyrivibrio group represented 12.98% and 10.95% of total bacteria in control and GO group, respectively. In libraries, clones were classified to the genus Pseudobutyrivibrio, Butyrivibrio and others within the family Lachnospiraceae. Additionally, some specific clones were observed in GO group, being classified to the genus Ruminococcus and others within the family Ruminococcaceae. Based on the criterion that the similarity was 97% or greater with database sequences, there were 29.73% and 18.42% of clones identified as known isolates (i.e. B. proteoclasticus and Ps. ruminis) in control and GO groups, respectively. Further clones identified as B. fibrisolvens (5.41%) and R. flavefaciens (7.89%) were specifically found in control and GO groups, respectively. The majority of clones resembled Ps. ruminis (98% to 99% similarity), except for Lachnospiraceae bacteria (87% to 92% similarity) in the two libraries. The two clone libraries also appeared different in Shannon diversity index (control 2.47 and GO group 2.91). Our results indicated that the Butyrivibrio group bacteria had a complex community with considerable unknown species in the goat rumen.

• 한국환경보건학회지
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• 제42권2호
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• pp.133-140
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• 2016

Objectives: A pilot study was undertaken to assess the bioaerosol levels in restaurants and determine the effects of variations in temperature, relative humidity, and air movement on these levels. It focused on the differences between kitchens and dining areas, as well as between summer and winter. Methods: A field survey was performed in six restaurants. An Anderson type air sampler was used for sampling bioaerosols, such as total suspended bacteria (TSB), Gram-negative bacteria (GNB), Gram positive bacteria (GPB), opportunistic bacteria (OP), Staphylococcus spp., and total suspended fungi (TSF). Results: The average levels of TSB were $1{\times}10^2CFU/m^3$ and of TSF they were $1{\times}10^0{\sim}10^1CFU/m^3$. The kitchens had higher bioaerosol levels compared to dining areas, and summer showed much higher levels than winter. The concentration of OP in summer was more than six-fold that of winter. S. aureus was detected both in kitchens and dining areas, even in winter. The main effect of air movement on TSB levels was significant (p<0.05), as was air temperature, relative humidity and air movement on TSF levels (p<0.05). Conclusion: There was a wide variation in bioaerosol levels among different restaurants. The results indicate that cooking foods may be a key factor affecting bioaerosol levels. The effects of air temperature and relative humidity reveal that bioaerosol levels may vary according to the season. The observation of pathogenic bacteria suggests that the hygiene management of establishments should be improved. Future research is needed to characterize the relation between bioaerosol levels and the occupant density of the dining area.