• Microbiology and Biotechnology Letters
• /
• v.20 no.4
• /
• pp.430-436
• /
• 1992

Hydrogen evolution by mixed fermentation of Clostn"dium butyn"cum and photosynthetic bacteria which were capable of consuming clostridial metabolites and evolving hydrogen was investigated. Acetate and butyrate formed from anaerobic clostridial fermentation were efficiently utilized by Rhodopseudomonas sPhaeroides K-7. For complete bioconversion of clostridial metabolites such as acetate and butyrate into hydrogen, mixed culture of both anaerobic organisms forming molecular hydrogen was performed. By the mixed culture, the yield of hydrogen production increased by 20 to 75% and the levels of clostridial metabolites such as acetate, butyrate decreased in the fermentation broth. Influence of cell mixing ratio. mixing time and inoculum level on hydrogen evolution by mixed culture were examined. And then cometabolic pattern compared with in pure culture was observed as time course.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1993.04a
• /
• pp.144-144
• /
• 1993

한국에서 유행하는 페염균 type을 결정하기 위한 기초 실험을 수행하여 서울대병원과 서울중앙병원의 환자로부터 분리한 88개의 폐염균주를 담즙산에 의한 용해도 및 Optochin에 대한 민감성 등을 측정하고 폐염균의 type을 결정하기 위해서 Double diffusion, Countercurrent immunoelectrophoresis, Rocket immunoelectrophoresis 방법 등으로 폐염균 항혈청과 반응하였다. 또한 ATCC로부터 구입한 폐염균주를 이용하여 배지조성의 변화에 따른 폐염균 생장을 측정하기 위해 CAT broth, Brain Heart Infusion broth, Defined Media에서 3가지 type의 균주(Type I, III, IV)를 접종하고 37$^{\circ}C$에서 배양하면서 1시간마다 550nm에서 흡광도를 측정하였다. 3가지 type (Type I, III, IV)의 폐염균주로부터 협막다당류를 phenol Iysis 추출법으로 폐염균 Capsule 다당류의 분리하여 Total Sugar 함량, Uronic acid 함량, 0-Acetyl 함량, 단백질 함량, 핵산 함량, 분자량분포 Countr-current immunoelectrophoresis 등을 실시하여 폐염균 백신 규격에 부합되는지 확인하였다. 수집한 88개의 폐염균주가 모두 담즙산에 의해 용해되고 6mm Optochin disc를 사용하였을때 성장 저지원이 모두 14mm 이상으로 나타나 감수성이 있어서 폐염균임을 확인하였으며 폐염균의 type 결정에 필요한 방법을 설정하였다. 배지조성에 따른 폐염균의 생장을 측정한 결과 CAT broth 에서는 Type I만이 잘 배양되었고 Type III, IV는 늦게 배양되었으나, Brain Heart Infusion broth에서는 3가지 Type이 모두 잘 배양되었고, Defined Media 에서는 Type I만이 성장되었을 뿐 나머지 두 Type은 배양되지 않았다. 본 실험방법으로 분리된 폐염균 다당류는 폐염균 백신 규격중의 6가지 항목에서 적합하였으며 Statens(Denmark)로부터 구입한 항체와 뚜렷한 침강선을 나타내었다.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.26 no.2
• /
• pp.198-206
• /
• 1981

A field research was conducted to evaluate the effects of inoculation of Rhizobium meliloti and lime application on the early growth of alfalfa, var. Luna, in an acid soil. Alfalfa seeds were inoculated by lime-peat pelleting method with $A_3$ strain isolated from alfalfa roots. Both inoculated and noninoculated seeds were sown in acid soil (pH 5.5) with three levels of lime application (1, 3, 6 ton/ha) on mid-April. Inoculated seeds produced many effective nodules in early stage and increased nitrogen and chlorophyll contents of leaf, consequently stimulating alfalfa growth. Pseudo nodules were found in noninoculated, while they were seldom formed in inoculated. Lime application increased soil pH, plant height, root length, and shoot and root weight. Liming effect on nodulation was significant at first cut, but no longer after then. Both inoculation and liming increased the forage yield of alfalfa. Inoculation and liming of 6 ton/ha together produced the highest yield. As compared to control plot of nitrogen application, the effect of seed inoculation only could be equal to about 120 kg/ha nitrogen application. The total nitrogen contents of forage were little affected by number or weight of nodules and amounts of lime application.

• KSBB Journal
• /
• v.16 no.1
• /
• pp.41-47
• /
• 2001

H. pylori is known to be a key pathogen of chronic gastric and duodenal ulcers. Bacterial adhesion to hosts is an essential step for bacterial infection and the inhibition of this adhesion provides a possible method for the treatment of the infection. The inhibitory effect of antibody lgY, produced from immunized hens with H. pylori antigen, was studied in vitro. The inhibition of H. pylori adhesion to AGS was as high as 90% using 0.5mg/ml of lgY, and almost 80% of the detachmentwas also achieved. The inhibitory effect of adhesion-inhibition candidates was investigated. Additives in combination with lgY increased the adhesion-inhibiting effect by about 30-50%. However, the adhesion molecules of H. pylori were varied and complex, therefore the further studies are necessary to develop an adhesion inhibitor and effective enough to be employed for the treatment of H.pylori, in vivo.

• Food Science and Preservation
• /
• v.6 no.4
• /
• pp.448-455
• /
• 1999

The starters, 0.3% of Leuconostoc mesenteroides, Lactobacillus brevis and Lactobacillus fermentum, were added in radish juice to process the radish juice by single and mixed cultures. The radish Juice was fermented for 7 days at 25$^{\circ}C$, 20 days at 15$^{\circ}C$, and 36 days at 5$^{\circ}C$. When fermented at 25$^{\circ}C$, the number of lactic acid bacteria in the juice made with mixed culture was higher than that of the single culture. But, juice fermented at low temperatures (15∼5$^{\circ}C$), the addition of starters was not effective, although there were some differences by inoculation strains. Although there was a little differences by inoculation strains, the content of nonvolatile organic acid and L-ascorbic acid were found more in the juice inoculated with lactic acid bacteria than the juice not inoculated. When the single and mixed cultures at the optimal maturity were tested, the significant difference was found at 5% level except the yeasty and moldy smell and the unripe taste. According to the preference test, the mixed-cultured radish juice incubated at 25$^{\circ}C$with Lactobacillus brevis and Leuconostoc mesenteroides were evaluated superior to commercial Dongchimi. As a result, taste and quality of radish juice was improved by addition of starters.

• Journal of Marine Bioscience and Biotechnology
• /
• v.2 no.3
• /
• pp.142-148
• /
• 2007

An agar-degrading marine bacterium, strain AS-3 was isolated from the seawater. The strain AS-3 was identified as Algibacter lectus AS-3 by 16S rDNA sequence. The optimum medium for agarase activity of the isolated strain was determined to be marine medium, marine broth 2216 containing 0.1% agar as carbon source. An extracellular agarase was purified 6.9-fold from the culture supernatant by ammonium sulfate precipitation, ion exchange chromatography and gel filtration methods. The optimum pH and temperature for this enzyme were 7.0 and $40-50^{\circ}C$, respectively. Antioxidative activity of the strain AS-3 was 62.4% in the supernatant cultured for 12 h.

• Korean journal of applied entomology
• /
• v.12 no.2
• /
• pp.79-82
• /
• 1973

1. In order to investigate Physiologic races of Puccinia gramininis f. sp. tritici as basic materials for tile breeding of resistant varieties to stem rust of wheat, this experiment was carried out during 1971 and 1973. 2. Twenty seven isolates of the fungus were identified as follows: two isolates of race 11, eight . isolates of race 17, and 21, four isolates of race 34, one each of race 37 and 56, respectively The remaining three isolates identified were not identical with the key issued by Stakman, et at in 1962. Therefore, the three new races were tentatively numbered $K_3,\;K_4\; and\; K_4,$ in addition to $K_l\;and\;K_2$ described in 1961. 3. Therefore, attempts to produce resistant varieties to stem rust of wheat should be accompanied by intensive investigation of Physiologic races of p. graminis f. sp. tritici in the future.

• Korean Journal Plant Pathology
• /
• v.3 no.4
• /
• pp.270-276
• /
• 1987

The fifty percent effective concentration (EC50) and the minimum inhibitory concentration (MIC) of iprodione on the resistant isolates of Alternaria mali obtained from infected leaves in Kyeongsan region ranged $550\~1,310{\mu}g/ml$ and $33,800-39,800{\mu}g/ml$, respectively. Conidia germination of the resistant isolates reached $70\%$ on PSA added with iprodione, $500{\mu}g/ml$ When treated with $500{\mu}g/ml$ iprodione soon after the inoculation the diameters of lesions on apple fruits 7days after inoculation with the resistant isolates were 1.6-14.6mm but no lesions appeared on those inoculated with the sensitive isolates. A similar trend of responses with the sensitive isolates was shown to benomyl, chlorothalonil, garbenda, thiophanatemethyl and triademefon with the resistant isolates. One isolate among the resistant ones was cross resistance to captan and folpet that were effective to the sensitive isolates.

• Journal of Korean Society of Forest Science
• /
• v.87 no.2
• /
• pp.253-259
• /
• 1998

The stimulated secretion of golden varnish sap by the infection of microorganisms on the bark of Dendropanax morbifera Lev. was observed in the natural habitats. Four candidate strains of such microorganisms(i.e., Sb1, Sb2, Sb3 and Sb4) were isolated from the bark of D. morbifera which was infected in natural. Of them, Sb3 and Sb4 strains showed stimulated secretion of golden vernish sap with the greatest stimulation by Sb4 strains. The yield of golden varnish sap from the bark of D. morbifera was boosted about 3.4~7.7 times by the inoculation of Sb4 strain in compassion with that collected from lacquer tree(Rhus verniciflua Stokes) by the traditional method. The mycelium color of Sb4 strain was grayish white. The optimum growth temperatures and pH were ranged from 30 to $35^{\circ}C$ and from pH 6.5 to 7.0.

• Korean Journal of Microbiology
• /
• v.48 no.3
• /
• pp.220-224
• /
• 2012

In order to reduce harmful biogenic amines in the traditionally fermented soybean products, five isolates with biogenic amines-degrading property were obtained from 83 traditionally fermented soybean products. The strains were found to reduce biogenic amines including histamine, tyramine, putrescine, and cadaverine by 27 to 92% in the cooked soybean containing 5.3% of each biogenic amine over 10 days of incubation. The morphological and biochemical tests and the phylogenetic relationships based on 16S rRNA gene sequences indicated that the five isolates were most closely related to Bacillus subtilis or B. amyloliquefaciens. The use of selected strains would be a potential control measure in manufacturing traditionally fermented soybean products that are difficult to control biogenic amine levels.