• Microbiology and Biotechnology Letters
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• v.40 no.3
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• pp.190-196
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• 2012

In this study, a total of more than 1,000 bacteria, including 739 species of aerobic bacteria, 80 species of urease producing bacteria and 303 species of photosynthetic bacteria, were isolated from red-pepper field soils located in the Gyeongsan Province of the Republic of Korea. Amongst these, 158 species of aerobic bacteria, 70 species of urease producing bacteria and 228 species of photosynthetic bacteria were found to be auxin producing soil bacteria through quantification analysis with the Salkowski test. The latter groupings were then tested for antifungal activities to ${\beta}$-Glucanase and siderophore using CMC congo red agar and CAS blue agar media. In addition, the selected strains were examined for antifungal activity against various phytopathogenic fungi on PDN agar media. Six strains; BCB14, BCB17, C10, HA46, HA143, and HJ5, were noted for their ability to both produce auxin and act as antifungal substances. 16S rDNA sequence comparison analyses of these six strains identified them as Bacillus subtilis BCB14, B. methylotrophicus BCB17, B. methylotrophicus C10, B. sonorensis HA46, B. subtilis HA143, and B. safensis HJ5.

• Microbiology and Biotechnology Letters
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• v.2 no.1
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• pp.1-7
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• 1974

For the purpose of producing cellulosic single-cell protein from the agricultural wastes, 172 strains of cellulose-assimilating bacteria were isolated from 102 samples of rotten woods, compost soils, soils and so on by the enrichment culture technique. The isolates were examined for their ability to utilize cellulose as carbon source, and then six strains were screened by their strong cellulose assimilating ability and identified as follows: 1. Among six strains of bacteria screened, five strains were identified as species belonged to the genus Cellulomonas and the remainder to the genus of Sporocytophaga. 2. The isolated Sporocytophaga species was identified as S. ellipsosporn because it has a ellipsoidal microcyst. 3. The isolated Cellulomonas species were identical to a strain of C. fimi, C. aurcgena, C. gelida, respectively and two strains to C. flavigena. 4. The isolated C. aurogena was proved to be a new variety becauuse it has different characteristics of assimilating pentoses such as arabinose and xylose from the strain discribed in Bergey's Manual.

• Natural Product Sciences
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• v.22 no.4
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• pp.299-306
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• 2016

This study aimed to establish the quantitative method to analyze the content of peroxynitrite-scavengers belonging to polyphenols in six Korean Quercus species (Quercus mongolica, Q. dentata, Q. acutissima, Q. alienta, Q. serrata, and Q. variabilis) by HPLC. The twelve peroxynitrite-scavengers, flavanols (catechins: (+)-catechin, (-)-epicatechin, and (-)-epigallocatechin), flavonols (kaempferol and quercetin), flavonol glycosides (astragalin, quercitrin, and isoquercitrin), flavonol acylated glycosides (astragalin 6''-gallate and isoquercitrin 6''-gallate), gallic acid and its dimer (ellagic acid) were analyzed by HPLC. Further, anti-Alzheimer's activity was assayed in a passive avoidance testusing mice by measuring the retention latency (sec), the concentration of acetylcholine (ACh), and acetylcholinesterase (AChE) activity. Simultaneous analysis of the extracts of the six Quercus leaves was achieved on a Capcell C18 column ($5{\mu}m$, $250mm{\times}4.6mm\;i.d.$) with a gradient elution of 0.05% HAc and 0.05% HAc in $CH_3CN$. In the extract of Q. mongolica leaves, the content of gallic acid (32.53 mg/g), (+)-catechin (28.78 mg/g), (-)-epicatehin (22.03 mg/g), astragalin 6''-gallate (20.94 mg/g), and isoquercitrin 6''-gallate (44.11 mg/g) and peroxynitrite-scavenging activity ($IC_{50}$, $0.831{\mu}g/ml$) were high. This extract delayed the retention latency and inhibited acetylcholinesterase activity in scopolamine-induced memory impairment of mice, suggesting that it has anti-Alzheimer's activity.

• Microbiology and Biotechnology Letters
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• v.41 no.4
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• pp.462-468
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• 2013

Jeotgal is a generic term given to the high-salt-fermented seafood of Korea. This study aimed at developing an overview of the bacterial community present in Ojingeo-jeotgal, a highly consumed type of jeotgal, which is made with squid. Bacteria were isolated and purified from two samples on six different kinds of media and identified by 16S rRNA gene sequence analysis. Among the 121 total isolates, the most dominant genus was Bacillus, followed by coagulase-negative staphylococci (CNS) and lactic acid bacteria (LAB). CNS were detected in both samples, but LAB were observed in only a single sample. Six strains of Bacillus species inhibiting the growth of food pathogens, Staphylococcus aureus and Vibrio parahaemolyticus, were selected from the 121 isolates. These were found to inhibit the growth of both pathogens in addition to displaying proteolytic activities on media containing 6% NaCl and 2% skim milk.

• Korean Journal of Environment and Ecology
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• v.12 no.4
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• pp.331-344
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• 1999

To study plant community structure and successional sere of the Kojedo District, Hallyo-Haesang National Park, fifty six plots were set up and surveyed(each plot $l00\m^2$). Fifty-six plots were classified into four community, Quercus variabilis-Zelkova serrata community(I), Q. variabilis-Cinnamomum japonicum-Neolitsea sericea community(II), Pinus thunbergii-C. japonicum-N. sericea community(III), P. thunbergii-P. densiflora community(IV) by TWINSPAN technique. Most area of forests in Kojedo district are artificial or coppice forest after artificial disturbance. The age of four community were about 35~40 years and the number of species 32~44 species per $600\m^2$. Ecological succession had been proceeded from deciduous broad-leaved species(Q. variabilis-Z. serrata etc.), P. thunbergii, P. densiflora to evergreen broad leaved forest(C. japonicum, N. sericea etc.).

• Korean Journal of Plant Resources
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• v.28 no.4
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• pp.411-418
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• 2015

Lonicera caerulea var. edulis is a rare species found in some alpine region of Korea. Genetic variation in L. caerulea var. edulis has been investigated by examining 161 individuals from six natural populations: Mt. Seorak 1, Mt. Seorak 2, Mt. Jeombong, Mt. Bangtae, Mt. Gyebang, Mt. Halla. The mean genetic diversity for all the six populations was 0.25 (S.I.). The highest genetic diversity was found in Mt. Seorak (S.I.=0.3158) and the lowest was in Mt. Gyebang (S.I.=0.1047). Comparatively low level of genetic diversity was observed (Ae=1.25, P= 64.6%, S.I.=0.25), which is a typical pattern for rare tree species. AMOVA showed exceptionally large proportion of genetic variations both for among populations (34.69%) and within populations (65.31%). Excluding Mt. Gyebang, the genetic variation among and within population was 18.71% and 81.29% respectively. The UPGMA dendrogram based on genetic distance is not suitable for geographic relationship. Genetic distance of Mt. Gyebang was most distant from the other populations. Excluding Mt. Gyebang, the genetic identities among the five populations were 0.95 to 0.97, which is very high similarity level of genetic identity. This low level of genetic variations and the lack of site in nature indicates that Lonicera caerulea var. edulis demanded a serious conservation.

• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.79-85
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• 2007

Rice bran application just after transplanting has been increasingly practiced as an herbicide-substitute for organic rice production in Korea. However, this practice is frequently reported to be unsatisfactory in weed suppression. An experiment with five treatments that combines flooding depth, rice bran application dose, and herbicide treatment was done in the paddy field to evaluate whether rice bran application under deep flooding can lead to a successful weed control in compensation for the single practice of rice bran application. Rice bran was broadcasted on the flood water surface just after deep flooding of 8 to 10cm that was started at seven days after transplanting. In the shallow flooding plot without herbicide six weed species were recorded: Monochoria vaginalis, Echinochloa crus-galli, Ludvigia prostrate, Cyperus amuricus, Aneima keisak, and Bidens tripartite. Among the first four dominant weed species, deep flooding significantly suppressed the occurrence of Echinochloa crus-galli and Cyperus amuricus while did not suppress the occurrence of Monochoria vaginalis and Ludwigia prostrate. On the contrary, rice bran application under deep flooding suppressed significantly Monochoria vaginalis and Ludwigia prostrate while didn't exert an additional suppression of Echinochloa crus-galli and Cyperus amuricus compared to deep flooding alone. Rice bran application and deep flooding suppressed complimentarily all the six weed species to a satisfactory extent except for Monochoria vaginalis of which suppression efficacy was 31.9%. Deep flooding reduced the panicle number substantially by inhibiting the tiller production, increased the spikelet number per panicle slightly, and leaded to a lower rice grain yield compared to shallow flooding with herbicide. Rice bran application under deep flooding mitigated the panicle reduction due to deep flooding, increased the spikelets per panicle significantly, and thus produced even higher grain yield in the rice bran application of 2000kg $ha^{-1}$ as compared to the shallow flooding treatment with herbicide. In conclusion, this practice applying rice bran under deep flooding would be promising to be incorporated as an integral practice for an organic rice farming system.

• Korean Journal of Plant Taxonomy
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• v.34 no.3
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• pp.205-220
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• 2004

Numerical analysis based on the 67 morphological characters from 28 populations of 6 species of Korean Rhus sensu lato (Anacardiaceae) was performed for the taxonomic delimitation. Based on the results of PCA with 47 quantitative characters, the sum of contributions for the total variance of three major principal components was 77,9% (PCl 35.2%, PC2 22.5% and PC3 20.2%). The sum of contributions for the total variance of three major principal components were 90,7% (PCl 37.7%, PC2 33.0% and PC3 20.0%) based on the results of PCA with 20 qualitative The characters. Two dimensional plotting from PCA results recognized six distinct species. UPGMA phenogram based on simple matching coefficient method recognized clear taxonomic delimitations among six taxa. On the cluster analysis, qualitative characters were more useful for grouping the species treated. Numerical analysis was very valuable to delimit the Korean taxa of Rhus s.l.

• Microbiology and Biotechnology Letters
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• v.47 no.3
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• pp.359-363
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• 2019

Meju is a spontaneously fermented soybean product produced in Korea. We isolated the bacteria of the genera Bacillus, Enterococcus, and Staphylococcus from 12 meju samples collected from five regions of Korea using selective media, and we identified them based on the sequence analysis of 16S ribosomal RNA and gmk (guanylate kinase) genes. Bacillus and Enterococcus strains were identified from all samples and the numbers of Bacillus strains in the 11 samples were >15% of the total cell number. Therefore, the genus Bacillus was confirmed as the predominant bacterial group of meju. Staphylococcus strains were identified from six samples. The identified 151 Bacillus isolates predominated in the following order: B. velezensis, B. sonorensis, B. subtilis, and B. licheniformis. Among the 165 Enterococcus isolates, 163 strains were identified as E. faecium. Eighty-two Staphylococcus isolates were classified into six species of coagulase-negative Staphylococcus group and S. xylosus was the predominant species.

• Journal of Korean Society on Water Environment
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• v.34 no.6
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• pp.602-620
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• 2018

Korean benthic macroinvertebrate community from 959 sites and 14 environmental factors that could affect the biological distribution were surveyed and analyzed. The 438 taxa were divided into six groups according to TWINSPAN. Based on the environmental factor values corresponding to each taxon, the average and range of environmental factors for each biological group tended to increase or decrease in eight environmental factors (altitude, slope, current velocity, fraction of fine particles in substrates, turbidity, $BOD_5$, T-N and T-P). As a result of discriminant analysis (hit ratio: 69.6 %), environmental factors that significantly influence the distribution of each biological group were $BOD_5$, altitude, catchment area, T-N, T-P and fraction of fine particles in substrates. The discriminant functions 1 and 2 classified the existing six biological groups (clustered by TWINSPAN) into five (group 1: highland highly sensitive group; group 2: lowland sensitive group, group; 3 and 4: lowland slightly tolerant group; group 5: lowland tolerant group; group 6: lowland highly tolerant group). Most of the benthic macroinvertebrates were identified in the species level. However, a few others were identified in genus or family level, too. Even the organisms belonging to the same genus or family may prefer different environmental factors in the species level, the identification of characteristic of the habitat environment preferred by organism and species level identification of these organisms are utmost. The results of this study may be used as basic information on environmental factors which can be considered in preservation and restoration research for biodiversity.