• The Korean Journal of Mycology
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• v.38 no.2
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• pp.120-124
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• 2010

This study was carried out to investigate interaction between mushroom mycelium and microorganisms in cotton waste media for the shelf cultivation of oyster mushroom. Two oyster mushroom farms was selected for this experiment. One was good mushroom farm (farmhouse I) and the other failed mushroom farm (farmhouse II). In farmhouse I, the inhibition microorganisms were higher toward the end of growth stage than the early stage, but the result of farmhouse II was opposite. Effects of the mycelium growth on plate culture showed same results on mushrooms as the earlier one. And the mycelium growth was influenced by secretory materials of microorganisms. Among of the isolates, Only few microorganism had inhibitory effects on either P. tolaasii or T. harzianum causing the disease of oyster mushrooms. But more microorganisms had inhibition effects on P. agarici.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.3
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• pp.239-244
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• 1989

This work was for the elucidation of heterogeneity in a natural population of Rhizobium japonicum existing in Seoul National University's Experiment Field and of sensitivities of R. japonicum isolates for several antibiotics by using a method based on intrinsic antibiotic resistance (IAR). In addition, the suitability of IAR method for the recognition of R. japonicum strain was elucidated. Twenty seven isolates from various soybean cultivars cultivated at SNU's Experiment Field were tested to 4 antibiotics (streptomycin sulphate, kanamycin sulphate, ampicillin, oxytetracycline);There were 21 different IAR patterns among 27 isolates. It demonstrated diverse distribution of R. japonicum strains in SNU's Experiment Field. Their growth was inhibited at from a low concentration of about $1{\mu}g/ml$ to a high concentration of $400{\mu}g/ml$ for streptomycin sulphate, ampicillin, and oxytetracyclin. For kanamycin sulphate, on the contrary, all 27 isolates showed their growth inhibitances at below the concentration of $12.5{\mu}g/ml$. Two isolates identified as different strains from each other by the previous seroimmunological tests showed the same sensitivities for 4 antibiotics, and it seemed that IAR method was not perfect for the exact recognition of R. japonicum strain.

• Korean Journal of Weed Science
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• v.30 no.2
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• pp.122-134
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• 2010

We investigated the levels of resistance and accumulation of terapyrroles, reactive oxygen species, lipid peroxidation, and antioxidative enzymes for reasons of growth reduction in herbicide-transgenic rice overexpressing Myxococcus xanthus, Arabidopsis thaliana, and human protoporphyrinogen oxidase (Protox) genes. The transgenic rice overexpressing M. xanthus (MX, MX1, PX), A. thaliana (AP31, AP36, AP37), and human (H45, H48, H49) Protox genes showed 43~65, 41~72 and 17~70-fold more resistance to oxyfluorfen, respectively, than the wild type. Among transgenic rice lines overexpressing Protox genes, several lines showed normal growth compared with the wild type, but several lines showed in reduction of plant height and shoot fresh weight under different light conditions. However, reduction of plant height of AP37 was much higher than other lines for the experimental period. On the other hand, the reduction of plant height and shoot fresh weight in the transgenic rice was higher in high light condition than in low light condition. Enhanced levels of Proto IX were observed in transgenic lines AP31, AP37, and H48 at 7 days after seeding (DAS) and transgenic lines PX, AP37, and H48 at 14 DAS relative to wild type. There were no differences in Mg-Proto IX of transgenic lines except for H41 and H48 and Mg-Proto IX monomethyl ester of transgenic lines except for MX, MX1, and PX. Although accumulation of tetrapyrrole intermediates was observed in transgenic lines, their tetrapyrrole accumulation levels were not enough to inhibit growth of transgenic rice. There were no differences in reactive oxygen species, MDA, ALA synthesizing capacity, and chlorophyll between transgenic lines and wild type indicating that accumulated tetrapyrrole intermediate were apparently not high enough to inhibit growth of transgenic rice. Therefore, the growth reduction in certain transgenic lines may not be caused by a single factor such as Proto IX, but by interaction of many other factors.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.625-631
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• 1997

This study was peformed to investigate the effects of Lycii fructus extracts on the growth and physiology of S. cerevisae D7l, L. casei KCTC 3165, and E. coli DH5. When Lycii fructus was added into solid culture media, the growth of S. cerevisea D7l and L. casei KCTC 3165 was increased, whereas that of E. coli DH5 was somewhat decreased. The growth of S. cerevisiea D7l and L. casei KCTC 3165 were much promoted in the culture media including methanol extract of 1.0% and 1.5%, respectively. E. coli DH5 was changed its morphology not only in 10% Lycii fructus juice but also 1.0% methanol and chloroform extract of Lycii fructus. Its size in those growth condition was eight times longer than that of the normal E. coli DH5. It was elucidated that elongation phenomenan of E. coli DH5 was also appeared by adding 0.135% of Na$^{+}$, $K^{+}$, and the mixture of Na$^{+}$ and $K^{+}$.TEX> +/.

• Food Science and Preservation
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• v.15 no.4
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• pp.568-575
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• 2008

The antimicrobial activities of raw garlic and garlic juice heated for 30 min at $65^{\circ}C,\;80^{\circ}C,\;and\;95^{\circ}C$ were investigated. Activities against food poisoning bacteria were measured. Raw garlic and garlic juice heated at $65^{\circ}C$ showed strong antimicrobial activities, but the antimicrobial activity of garlic juice heated at $80^{\circ}C$ was much less, and no antimicrobial activity was seen in garlic juice heated at $95^{\circ}C$. Raw garlic and garlic juice heated at $65^{\circ}C$ completely inhibited the growth of Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Salmonella typhymurium, and Salmonella enteritidis at levels below 0.2%(w/v) of garlic solids. The inhibitory effects of garlic juice heated at $80^{\circ}C$ were much lower, against all bacteria tested.

• The Korean Journal of Food And Nutrition
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• v.23 no.4
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• pp.664-669
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• 2010

Lactic acid bacteria from traditional Korean foods of Tarak and Kimchi was isolated and characterized against carcinogenic Helicobacter pylori. Five Tarak and 30 Kimchi, traditional lactic acid-fermented foods, were collected from Andong area and the markets in Seoul, respectively and 15 lactic acid bacteria were isolated. Among them, two isolates were selected from high growth-inhibitory activities on H. pylori. The isolates were identified as Streptococcus thermophilus LAB kw15 from Tarak and Leuconostoc mesenteroides LAB kw5 from Kimchi by the biochemical characteristics and 16S DNA sequencing. The culture solutions of the isolates adjusted to pH 7.0 showed H. pylori inhibition. The isolates grew well and H. pylori did not grow during the co-culture with those strains. Therefore, L. mesenteroides LAB kw5 and S. thermophilus LAB kw15 might be the candidates as the functional lactic acid bacteria for improving stomach health.

• The Korean Journal of Mycology
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• v.51 no.3
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• pp.205-217
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• 2023

This study aimed to produce novel bioactive compounds from non-pathogenic pigmented wild yeasts. Culture supernatants and cell-free extracts of non-pathogenic pigmented yeast strains were prepared, and their physiological functionalities and enzyme activities were measured. Cell-free extracts from Rhodosporidium paludigenum HHGG35-1 and culture supernatants from Rhodosporidium diobovatum NMD18-1 demonstrated very high antioxidant activity (76.6%) and anti-gout xanthin oxidase inhibitory activity (86.2%), respectively. Maximal production of the antioxidants (76.9%) was obtained when Rh. Paludigenum HHGG35-1 was cultured in a yeasts extract-peptone-dextrose (YPD) medium (pH 6.5) at 30℃ for 24 h. The xanthin oxidase inhibitor was also maximally produced (91.6%) when Rh. Diobovatum NMD18-1 was cultured at 30℃ for 96h in a YPD medium (pH 6.5). Rh. Paludigenum HHGG35-1 was oval in shape and formed ascospre. The Rh.diobovatum NMD18-1 specimen displayed dimensions of 1.6 × 1.6 ㎛ and produced ascospores; however, it did not form pseudomycelium. Both of Rh. Paludigenum HHGG35-1 and Rh. Diobovatum NMD18-1 grew well in a 40%-glucose-containing YPD medium and 10%-NaCl-containing YPD medium.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.2
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• pp.181-187
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• 2014

Polycyclic aromatic hydrocarbons (PAHs) are a group of ubiquitous hazardous pollutants derived from fossil fuel, various combustion sources and pyrolysis of a wide range of plastics. Because PAHs can be uptake into crop plants, the inhibitory effects on rice and soybean plants were examined in greenhouse and growth chamber experiment. Soil-applied PAHs (phenanthrene of 0, 10, 30, 100 ppm) slightly reduced the plant height and dry weight both in transplanted rice and soybean plant. The inhibitory effect on growth was greater in soybean than rice. Plant height of soybean plants treated by 100 ppm was 58.9 cm and this value was 87.2% of untreated plant. In rice plant, the plant height was less inhibited (96.0% of untreated plant) by 100 ppm at 80 days after treatment (DAT). However, leaf chlorophyll content and chlorophyll fluorescence were less inhibited by PAHs at late growth stage (after heading) although the photosynthesis-related parameters were slightly inhibited from 20 DAT to 70 DAT. In agar medium experiment with infant seedlings, inhibition of seedling length and fresh weight by phenanthrene at 100 ppm were greater as compared to the experiment with adult plant in pot. Seedling length and fresh weight were reduced by 54.2% and 33.3% for rice and 27.9% and 13.2% for soybean, respectively. The results reflected that PAHs were more inhibitory during juvenile stage than adult stage and more inhibitory to rice plant than soybean for juvenile stage.

• Korean Journal of Food Science and Technology
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• v.9 no.4
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• pp.306-312
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• 1977

A mixed culture of Candida tropicalis and Trichosporon cutaneum was carried out using a n-paraffin medium. The growth of C. tropicalis was markedly enhanced by the mixed culture with T. cutaneum which did not grow on n-paraffin. C. tropicalis extracellularly excreted free fatty acids as metabolic products of n-paraffin in the culture medium. T. cutaneum appeared to assimilate these free fatty acids which were growth inhibitors for C. tropicalis, threreby enhancing the growth of C. tropicalis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.4
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• pp.342-348
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• 2005

In this study, novel strains showing better protein degradation activity were isolated for the production of effective compost from garbages. Well growing bacteria with clear zone on the skim milk agar media were isolated . The strain was identified as Bacillus subtilis PNV-1 through various biochemical tests, Bergy's manual of determinative bacteriology and 165 rDNA partial sequence. The extracellular protease of the strain PNV-1 has its activity at broad pH and the optimal temperature was $50^{\circ}C$. Also, the strain PNV-1 was highly tolerant to high concentration of salt, red/black pepper and mustard.