• Korean Journal of Ichthyology
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• v.22 no.3
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• pp.201-205
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• 2010

One specimen of a natural hybrid of an Oplegnathus (Oplegnathus fasciatus $\times$ Oplegnathus punctatus) was found in Tongyeong, Korea in August 2008. We, herein, describe its morphological and genetic characteristics and compare them with those of O. fasciatus and O. punctatus. In morphology, the hybrid showed many distinctive black rounded blotches on body sides and four faint vertical bars, being in those features similar to O. punctatus. Although the counts and measurements of the hybrid mostly overlapped between O. fasciatus and O. punctatus, the Oplegnathus hybrid resembled O. punctatus in the ratio of pelvic-fin length in standard length: Oplegnathus hybrid (26.7%) was closer to O. punctatus (26.4%) than to O. fasciatus (17.2~23.6%). In genetics, as a result of analysis of 510 base pair sequences of mitochondrial DNA 16S rRNA, the hybrid was closer to O. fasciatus (d=0.000~0.010) than to O. punctatus (d=0.020). Our results suggest that the natural hybridization represented by the subject specimen occurred between an O. fasciatus female and an O. punctatus male.

• Korean Journal of Microbiology
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• v.37 no.2
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• pp.114-119
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• 2001

Many isolates from different forest soil layers did not show appreciable growth on full strength of the conventional nutrient broth (NB medium) but grow on its 100-fold dilution (DNB medium). These isolates were divided into four types according to organic nutrient concentration in the growth medium from $1^{-1}\;to\;10^{-4}$dilution of normal NB medium. Oligotrophic bacteria were type II and type IV which grew in $10^{-4}$ dilution of NB (1 mg C/l) medium. Sixty strains were isolated for obligate oligotrophic bacteria. Chemotaxonomic and phylogenetic characteristics of eleven isolates of acetylene-reducing (nitrogen-fixing) oligotrophic bacteria from forest soil were investigated. They showed similar characteristics: the cellular fatty acid mainly consisted of straight-chain unsaturated $C_{18:1}$ (60-84% of total fatty acids). Ubiquinone Q-10 and a high guanine plus-cytosine content(61-64 mol%) were found. Eleven isolates of nitrogen-fixing oligotrophic bacteria were found to be closely related by full 16S rDNA sequence simility and many common taxonomic traits. Analysis of full 16S rDNA sequences of eleven isolates indicated that they were more closely related to Bradyrhizobium (similarity values: 98.1-98.8%), Agromonas, Nitrobacter, and Afipia.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.49-49
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• 2014

In order to find indigenous beneficial fungal species from crop field soils of Nigeria, 23 soil samples were collected from various places of Nigeria in June, 2013 and fungi were isolated through serial dilution technique. Isolated fungi were purified and differentiated according to their morphological and microscopic characteristics. In total, 38 different representative isolates were recovered and the genomic DNA of each isolates was extracted using QIAGEN$^{(R)}$ Plasmid Mini Kit (QIAGEN Sciences, USA) and the identification of fungi was carried out by sequence analysis of internal transcribed spacer (ITS) region of the 18S ribosomal DNA (18S rDNA). Recovered isolates belonged to 9 fungal genera comprising Fusarium, Aspergillus, Chaetomium, Coniothyrium, Dipodascaceae, Myrothecium, Neosartorya, Penicillium and Trichoderma. Aspergillus spp., Penicillium spp. and Trichoderma spp. were the most dominant taxa in this study. The antagonistic potentiality of species belonged to Trichoderma against 10 phytopathogenic fungi (F. oxysporum, C. gloesporoides, P. cytrophthora, A. alternata, A. solani, S. rolfsii, F. solani, R. solani, S. sclerotiorum and P. nicotiana) was assessed in vitro using dual culture assay. The dual culture assay results showed varied degree of antagonism against the tested phytopathogens. The potential Trichoderma spp. will be further evaluated for their antagonistic and plant growth promotion potentiality under in vivo conditions.

• Food Science and Biotechnology
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• v.16 no.1
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• pp.133-137
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• 2007

The Strain TFM-7, Which has an antitumor effect, was isolated from Kefir and identified based on analysis using the API 50 CHL kit and 265 rDNA sequencing. Strain TFM-7 was confirmed to belong to the genus Kluyveromyces. Analysis of the 265 rDNA nucleotide sequences found strain TFM-7 to be related to Kluyveromyces marxianus. NRRL Y-828IT. K. marxianus. TFM-7 was cultured with potato dektrose broth medium at $27^{\circ}C$ for 72 hr, and its inhibition effects on the proliferation of seven tumor cell lines and a normal cell line were assessed using the MTT assay. The antitumor effects and growth characteristics of K. marxianus TFM-7 were investigated during a culture period of 7 days. By the $3^{rd}\;day$, K. marxianus TFM-7 showed a dry cell weight 2.39 g/L, a pH of 4.39, an ethanol content of 0.89%, and an inhibition effect on the proliferation of seven tumor cell lines above 50%, except for A-549 tumor cell line. K. marxianus TFM-7 was the most effective at inhibiting the growth of Hep-2 cell line among all tumor cell lines tested. Growth inhibition of a normal cell line, NIH/3T3, was less than 35%, suggesting a decreased level of cytotoxicity toward normal cells. These results indicate that K. marxianus TFM-7 may have used as a yeast strain with antitumor activity.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.836-840
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• 2011

In order to isolate thermophilic compost-promoting bacteria with high activity of cellulase and xylanase, spent mushroom substrates with sawdust were collected from mushroom cultivation farm, Jinju, Gyeongnam in Korea. Among of the isolates, one strain, designated SJ21 was selected by agar diffusion method. The strain SJ21 was identified as members of the Bacillus lincheniformis by biochemical characteristics using Bacillus ID kit and VITEK 2 system. Comparative 16S rDNA gene sequence analysis showed that strain SJ21 formed a distinct phylogenetic tree within the genus Bacillus and was most closely related to Bacillus subtilis with 16S rDNA gene sequence similarity of 99%. On the basis of its physiological properties, biochemical characteristics and phylogenetic distinctiveness, strain SJ21 was classified within the genus Bacillus, for which the name Bacillus sp. SJ21 is proposed. The cellulase and xylanase activity of Bacillus sp. SJ21 was slightly increased according to bacterial population from exponential phase to stationary phase in growth curve for Bacillus sp. SJ21.

• Parasites, Hosts and Diseases
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• v.53 no.5
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• pp.641-645
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• 2015

Fascioliasis, a food-borne trematode zoonosis, is a disease primarily in cattle and sheep and occasionally in humans. Water dropwort (Oenanthe javanica), an aquatic perennial herb, is a common second intermediate host of Fasciola, and the fresh stems and leaves are widely used as a seasoning in the Korean diet. However, no information regarding Fasciola species contamination in water dropwort is available. Here, we collected 500 samples of water dropwort in 3 areas in Korea during February and March 2015, and the water dropwort contamination of Fasciola species was monitored by DNA sequencing analysis of the Fasciola hepatica and Fasciola gigantica specific mitochondrial cytochrome c oxidase subunit 1 (cox1) and nuclear ribosomal internal transcribed spacer 2 (ITS-2). Among the 500 samples assessed, the presence of F. hepatica cox1 and 1TS-2 markers were detected in 2 samples, and F. hepatica contamination was confirmed by sequencing analysis. The nucleotide sequences of cox1 PCR products from the 2 F. hepatica-contaminated samples were 96.5% identical to the F. hepatica cox1 sequences in GenBank, whereas F. gigantica cox1 sequences were 46.8% similar with the sequence detected from the cox1 positive samples. However, F. gigantica cox1 and ITS-2 markers were not detected by PCR in the 500 samples of water dropwort. Collectively, in this survey of the water dropwort contamination with Fasciola species, very low prevalence of F. hepatica contamination was detected in the samples.

• Journal of Microbiology and Biotechnology
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• v.26 no.2
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• pp.337-346
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• 2016

Three combinations of molecular chaperones from Escherichia coli (i.e., DnaK-DnaJ-GrpE-GroEL-GroES, GroEL-GroES, and DnaK-DnaJ-GrpE) were overproduced in E. coli BL21, and their in vitro stabilizing effects on a nitrile hydratase (NHase) were assessed. The optimal gene combination, E. coli groEL-groES (ecgroEL-ES), was introduced into Rhodococcus ruber TH3. A novel engineered strain, R. ruber TH3G was constructed with the native NHase gene on its chromosome and the heterologous ecgroEL-ES genes in a shuttle plasmid. In R. ruber TH3G, NHase activity was enhanced 37.3% compared with the control, TH3. The in vivo stabilizing effect of ecGroEL-ES on the NHase was assessed using both acrylamide immersion and heat shock experiments. The inactivation behavior of the in vivo NHase after immersion in a solution of dynamically increased concentrations of acrylamide was particularly evident. When the acrylamide concentration was increased to 500 g/l (50%), the remaining NHase activity in TH3G was 38%, but in TH3, activity was reduced to 10%. Reactivation of the in vivo NHases after varying degrees of inactivation was further assessed. The activity of the reactivated NHase was more than 2-fold greater in TH3G than in TH3. The hydration synthesis of acrylamide catalyzed by the in vivo NHase was performed with continuous acrylonitrile feeding. The final concentration of acrylamide was 640 g/l when catalyzed by TH3G, compared with 490 g/l acrylamide by TH3. This study is the first to show that the chaperones ecGroEL-ES work well in Rhodococcus and simultaneously possess protein-folding assistance functions and the ability to stabilize and reactivate the native NHases.

• Journal of Microbiology and Biotechnology
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• v.20 no.10
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• pp.1386-1392
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• 2010

A bacterial strain designated GR5$^T$, previously isolated from a freshwater culture pond in Taiwan while screening for bacteria for antimicrobial compounds, was characterized using a polyphasic taxonomic approach. Strain GR5$^T$ was found to be Gram-negative, aerobic, greenish-yellow colored, rod-shaped, and motile by means of a single polar flagellum. Growth occurred at $10-40^{\circ}C$ (optimum, $35^{\circ}C$), pH 7.0-8.0 (optimum pH 8.0), and with 0-2.0% NaCl (optimum, 0.5-1.0%). The major fatty acids were $C_{16:1}{\omega}7c$(36.3%), $C_{16:0}$(16.6%), $C_{12:0}$ 3-OH (12.5%), and $C_{18:1}{\omega}7c$(9.1%). The major respiratory quinone was Q-8, and the DNA G+C content of the genomic DNA was 51.9 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain GR5$^T$ belongs to the genus Rheinheimera, where its most closely related neighbors are Rheinheimera texasensis A62-14B$^T$ and Rheinheimera tangshanensis JA3-B52$^T$ with sequence similarities of 98.1% and 97.5%, respectively, and the sequence similarities to any other recognized species within Gammaproteobacteria are less than 96.5%. The mean level of DNA-DNA relatedness between strain GR5$^T$ and R. texasensis A62-14B$^T$, the strain most closely related to the isolate, was $26.5{\pm}7.6%$. Therefore, based on the phylogenetic and phenotypic data, strain GR5$^T$ should be classified as a novel species, for which the name Rheinheimera aquatica sp. nov. is proposed. The type strain is GR5$^T$ (=BCRC 80081$^T$=LMG 25379$^T$).

• Research in Plant Disease
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• v.29 no.4
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• pp.420-424
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• 2023

In 2020, within the Dongbaekdongsan area in Jeju Island, a Septobasidium sp. associated with a felt disease in Castanopsis sieboldii (Makino) Hatus. ex T. Yamaz. & Mashiba was identified. The symptom included the presence of brown, thin, and silk-like mycelial mats attached to the tree's bark, displaying variations in size from large to small. To induce hyphal growth, the samples collected were incubated in a moist chamber, and the newly formed hyphae were subjected to genomic DNA extractions. The nucleotide sequences of the internal transcribed spacer and small subunit rDNA genes were determined, and molecular characteristics among the isolates were investigated through polymerase chain reaction-based restriction fragment length polymorphism analysis. This Septobasidium sp. exhibited distinct morphological and phylogenetic features compared to those that were previously reported in South Korea. Consequently, this strain is taxonomically classified as a provisionally novel species of Septobasidium. Furthermore, the observed felt disease exhibited a high degree of host specificity, as it was exclusively identified in C. sieboldii without occurrence in other tree species at the time of observation.

• Mycobiology
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• v.45 no.2
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• pp.110-113
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• 2017

Severe root rot was observed in fields of cabbages (Brassica oleracea L.) in 2015 in China. Cardinal symptoms of this disease included root rot and wilting leaves. A fungus was isolated from diseased tissues consistently. Based on the morphological features and molecular analysis of the ITS-5.8S rDNA and D1/D2 domain of the 28S rRNA gene, it was identified as Plectosphaerella cucumerina. This is the first report of P. cucumerina causing cabbage root rot in China and the world.