• Korean Journal of Microbiology
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• v.54 no.4
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• pp.410-419
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• 2018

It is urgently required to construct safety data on agricultural by-products imported for use as medium materials for domestic mushroom production. However, research on microorganisms is insufficient. This study was conducted to investigate the presence of bacteria that have the possibility of harmful effects on human, plants and mushroom in wheat straw, peatmoss, cottonseed hull, cottonseed meal, and beet pulp imported from Australia, Canada, China, Egypt, Germany. Bacteria were found in the range of $1.35{\times}10^2$ to $8.34{\times}10^6CFU/g$. As a result of 16S rDNA sequence analysis, total of 19 genera and 45 species of bacteria were identified. Bacillus genus was dominant, followed by Paenibacillus genus. At the species level, diverse species was in the order of Firmicute, Proteobacteria and Actinobacteria. Regarding the agricultural by-products, straw and peat moss had more diverse bacteria than other agricultural by-products. Among the indentified bacteria, 6 species of 5 genera (Enterobacter asburiae, Enterobacter ludwigii, Stenotrophomonas maltophilia, Pseudomonas monteilii, Bacillus anthracis, and Cellulosimicrobium funkei) were present as potent harmful bacteria to human. Surprisingly, both the human and plant pathogenic Klebsiella pneumoniae subsp. pneumonia was present. Bacillus altitudinis was present as a plant pathogen. Lysinibacillus sphaericus, an insect pathogen, and Ochrobactrum pseudogrignonense, a mushroom pathogen, were also present. The results of this study confirmed that several kinds of pathogenic bacteria were present in the agricultural by-products for the mushroom cultivation medium imported into Korea. Our work suggests that hygiene inspection and management is urgently needed for imported agricultural by-products to be safely used for mushroom production.

• Journal of Photoscience
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• v.11 no.32
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• pp.55-59
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• 2004

The present investigation is an attempt to create an optimized protocol for a bactericidal modality of different powers of He-Ne laser radiation to eliminate periodontitis disease causing bacteria from dental plaques. Periodontitis is most prevalent infectious disease of men and caused by a limited number of Gram negative oral bacteria. Porphyromonas gingivalis and Streptococcus sanguis are the important bacteria responsible for periodontitis diseases. Effect on periodontitis disease causing bacteria were produced by the exposure of different powers of He-Ne laser light i.e. 9 mW, 17 mW and 26 mW of red colour of wavelength 632.8 nm in two different periods of time i.e. 10 min. and 20 min. in the presence of dye Methylene blue (MB) used as a photosensitizer. The results have been shown in terms of percentage inhibition of colony forming units (cfu.) of bacteria. This study has shown that maximum inhibition of cfu. were observed in Laser+MB-20 min. exposure time. This inhibition was followed by Laser+MB-10 min., but minimum inhibition was seen in Laser only at 10 min. exposure. In case of effect of methylene alone on the cfu. of bacteria, it was seen that MB have not shown more inhibition of cfu. and it had shown that the no. of cfu. are very similar to that of control. The above observation of the present study was seen in case of every 3 different type of used powers of laser for both the bacteria. Maximum percentage inhibition of cfu. were seen in case of 26mW powers of He-Ne laser, which was 67. 28% to 61.42% for Porphyromonas gingivalis and Streptococcus sanguis respectively. So, increasing the power of laser (safe range for dentistry is 3-30 mW) under conditions shows an increased percentage inhibition of cfu. Thus the present investigation may be a useful adjunct with mechanical debridement in the prevention of recolonization of subgingival lesions by pathogenic microorganisms which are harmful and drug resistant.

• Korean Journal of Veterinary Service
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• v.40 no.2
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• pp.119-131
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• 2017

Among different types of spoilage, microbial contamination can cause feed decomposition, which results in decreases in feed intake and productivity, infection, and breeding disorder. During the storage time, various microbes have a chance to inoculate with depreciation of feed and to infect the animals. We investigated bacteria that inhabit diverse feed ingredients and complete feed which have been stored for a few months. We isolated and identified 30 genera and 62 species of bacteria. Among these 62 species, 21 species were of non-pathogenic bacteria, 18 species were of pathogenic bacteria, 9 species were of opportunistic pathogens, and 14 species were of unknown bacteria. Pantoea allii and 24 species showed proteolytic enzyme activity. We also confirmed that 6 species including Pseudomonas psychrotolerans showed ${\alpha}$-amylase activity, and 29 species including Burkholderia vietnamiensis showed cellulase activity. Microbacterium testaceum and 3 species showed resistance to Ampicillin, Kanamycin, Streptomycin, Gentamicin, Carbenicillin, and Erythromycin ($50{\mu}g/mL$). Using mealworm larvae (Tenebrio molitor L.) as a model for pathogenicity, we confirmed that 8 species including Staphylococcus xylosus had pathogenicity for mealworm larvae. Especially, Enterobacter hormaechei, Staphylococcus xylosus, and Staphylococcus hominis were reported as being pathogenic for humans. This research suggests that hygienic management of animal feed is essential because beneficial and harmful bacteria can inhabit animal feed differently during storage and distribution.

• Korean Journal of Microbiology
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• v.11 no.4
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• pp.175-180
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• 1973

This study was attempted to see more clear relationships among the enterobacteria, especially between the intestinal normal flora and pathogenic bacteria. It has been known that some intestinal normal flora produce the bactrial metabolites that are harmful to other enteric bacteria. One of the metabolites is known as colicin, the protein fraction, which possesses certain degree of inhibitory effect against other bacterial growth fraction, whih possesses certain degree of inhibitory effect against other bacterial growth. As a preliminary study for a colicin purification, the antagonistic effect of E, coli to groups of Salmonella and Shigella has been studied by means of in vitro quantitative culture method. 1. E.coli showed definite inhibitory effects aganist both Salmonella and Shigella groups in the mixture of two organisms. 2. The inhibitory effects of E.coli in the E.coli-Salmonella and the E.coli-Shigella mixture occurred from 4 hours incubation following the inoculation. 3. Even the complete inhibition of pathogenic enteric bacterial growth was noticed in the E.coli-Salmonella mixture at overnight incubation. 4. Among the diluted mixtures, 1:100, 1:1,000, and 1:10,000, survival rate of pathogenic enteric bacteria in the mixtures with E.coli showed least affected at the 1:1,000 dilution. 5. It was found that the antagonistic effect aganist groups of Salmonella-shigella was depending upon the groups of the genera.

• Biomedical Science Letters
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• v.8 no.2
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• pp.95-99
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• 2002

Endocrine disruptors are chemicals which can be found in our normal daily life. They can be easily ingested through plastic food containers, pesticides, etc. They include DDT, bisphenol A, benzophenone and phenylphenol, etc. Endocrine disruptor can be very harmful and toxic because it disrupts the normal function of the endogenous endocrine system. It has been reported that endocrine disruptor can cause the fatal strike in reproductive system central nervous system and the other part of the body. We have examined if the growth of lactic acid bacteria could be resistant to the endocrine disruptor. We have used Lactobacillus delbruekii as an experimental strain and benzophenone and phenylphenol for the comparison purpose. Experiments included the evaluation of turbidity, absorbance and actual cell counts. Although Lactobacillus delbruekii showed the higher resistance to benzophenone than phenylphenol it was still resistant to both benzophenone and phenylphenol. Because the experimental concentrations of benzophenone and phenylphenol were so high to compare with the actual concentration we meet in daily life, Lactobacillus delbruekii was considered to be sufficient to survive in the environmental concentration of these endocrine disruptors. This study should contribute to the development of fermented beverage with beneficial effect by lactic acid bacteria.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.249-254
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• 2013

As part of a study on insects as food, the nutritional and harmful components in the mealworm (Tenebrio molitor) were analyzed. In addition, due to a recent introduction of live Chinese mealworms in the Korean market, components between Korean and Chinese mealworms were compared. Analysis of general composition (moisture, crude protein, crude fat, crude ash, crude fiber, and carbohydrates) showed that crude protein (50.32~52.79%) was abundant in both Korean and Chinese mealworm powders, with the protein content in the Chinese mealworm powder higher than that in the Korean mealworm powder by 2.67%. The amino acid compositions were similar, but the fatty acid compositions differed in the Korean and Chinese mealworm powders. The unsaturated fatty acid contents were 76.80~80.55% of the total fatty acid content in the mealworms. The linoleic acid contents in the Korean and Chinese mealworms were $20.8{\pm}1.1%$ and $34.69{\pm}1.9%$; the linolenic acid contents were 0.47% and 1.31%; and the oleic acid contents were $51.40{\pm}0.9%$ and $40.20{\pm}1.5%$, respectively. With respect to harmful components, such as heavy metals and bacteria that cause food poisoning, bacteria such as Escherichia coli O157:H7 and Salmonella spp. were not detected in both Korean and Chinese mealworms, and the mercury content was below the standard values for common foods (Korea, 0.03 mg/kg; China, 0.08 mg/kg).

• Korean Journal of Environmental Agriculture
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• v.34 no.2
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• pp.139-148
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• 2015

BACKGROUND: The aim of this study was to isolate and identify algicidal bacterium that tends to kill the toxic dinoflagellate Alexandrium catenella, and to determine the algicidal activity and algicidal range of algicide. METHODS AND RESULTS: Among of algicidal bacteria isolated in this study, NH-3 isolate was the strongest algicidal activity against A. catenella. NH-3 isolate was identified on the basis of biochemical characteristics and analysis of 16S rRNA gene sequences. The NH-3 isolate showed over 99% homology with Arthrobacter oxydans, and was designated as Arthrobacter sp. NH-3. The optimal culture conditions were $25^{\circ}C$, initial pH 7.0, and 2.0% (w/v) NaCl concentration. The algicidal activity of Arthrobacter sp. NH-3 was significantly increased to maximum value in the late of logarithmic phase. Arthrobacter sp. NH-3 showed algicidal activity through indirect attack, which excreted active substance into the culture filtrate. When 10% culture filtrate of NH-3 was applied to A. catenella, 100% of algal cells were destroyed within 30 h. In addition, the algicidal activities were increased in dose and time dependent manners. The pure algicide was isolated from the ethyl acetate extract of the culture filtrate of NH-3 by using silica gel column chromatography and high performance liquid chromatography (HPLC). We investigated the algicidal activity of this algicide on the growth of harmful algal bloom (HAB) species, including A. catenella. As a result, it showed algicidal activity against several HAB species at a concentration of $100{\mu}g/mL$ and had a relatively wide host range. CONCLUSION: Taken together, our results suggest that Arthrobacter sp. NH-3 and its algicide could be a candidate for controlling of toxic and harmful algal blooms.

• Journal of Microbiology
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• v.43 no.6
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• pp.493-498
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• 2005

The safety assessment of Bifidobacterium longum SPM1205 isolated from healthy Koreans and this strain's inhibitory effects on fecal harmful enzymes of intestinal microflora were investigated. The overall safety of this strain was investigated during a feeding trial. Groups of SD rats were orally administered a test strain or commercial reference strain B. longum $1\times10^9\;CFU/kg$ body weight/day for four weeks. Throughout this time, their feed intake, water intake and live body weight were monitored. Fecal samples were periodically collected to test harmful enzyme activities of intestinal microflora. At the end of the four-week observation period, samples of blood, liver, spleen, kidney, and gut tissues were collected to determine for hematological parameters and histological differences. The results obtained in this experiment demonstrated that four weeks of consumption of this Bifidobacterium strain had no adverse effects on rat's general health status, blood biochemical parameters or histology. Therefore, it is likely to be safe for human use. Fecal harmful enzymes such as $\beta-glucosidase,\;\beta-glucuronidase$, tryptophanase and urease, were effectively inhibited during the administration of the B. longum SPM1205. These results suggested that this B. longum SPM 1205 could be used for humans as a probiotic strain.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.841-844
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• 2001

Free radicals cause many diseases and aging. In our body coexist useful and harmful bacteria. Some useful intestinal bacteria such as L. plantarum, B. adolescentis, B .bifidum, B. infantis, C. butyricum were presented positive growth in culture medium bearing natural products. L. plantarum was more effectively grown by mixed natural products of CORNI FRUCTUS+THEAE FOLIUM+COPTIDIS RHIZOMA+PAEONIA JAPONICA, B. adolescentis was BEIAMCANDA CHINENSIS+ANGELICAE GIGANTIS RADIX+EPIMEDII HERBA+PAEONIA JAPONICA, B. bifidum was NELUMBO NUCLFERA GAERTNER+THEAE FOLIUM+BEIAMCANDA CHINENSIS+CORNI FRUCTUS, B. infantis was THEAE FOLIUM+CHELIDONIUM MAJUS L.+ASTRAGALI RADIX+EPIMEDII HERBA, C. butyricum was EPIMEDII HERBA+PUERARIAE RADIX+NELUMBO NUCLFERA GAERTNER+PAEONIA JAPONICA,etc. These natural products will support an important role in bio-industry.

• Biomolecules & Therapeutics
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• v.7 no.4
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• pp.385-389
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• 1999

The injibitory effect of Bacillus licheniformis AJ isolated from genitourinary normal flora as a new probiotics on the growth of diarrheal pathogens was studied. This B. licheniformis AJ inhibited the growth of E.coli O-157. Salmonella typhi and Shigella sonnei as well as the infectivity of rotavirus. However, it did not inhibit the growth of Helicobacter pyloriand human intestinal bacteria although it inhibited the harmful enzyme activity of human intestinal bacteria. B. licheniformis AJ seems to excret heat-lable growth-inhibitory protein, bacteriocin, into the media. These results suggest that B. lichenoformis AJ could be used as a new type of probiotics.