• The Korean Journal of Mycology
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• v.46 no.4
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• pp.505-510
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• 2018

Peronospora is the largest genus of the order Peronosporales (Oomycota) and contains more than 550 accepted species, which causes downy mildew on many economically important crops. During a survey of downy mildew flora in Korea, a previously unreported species of Peronospora has been found on Corydalis ambigua. Based on molecular phylogenetic and morphological analyses, the causal agent was identified as Peronospora bulbocapni. This is the first report of Peronospora bulbocapni occurring on Corydalis ambigua in Korea.

• Journal of Microbiology and Biotechnology
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• v.13 no.1
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• pp.110-118
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• 2003

Pseudomonas syringae pv. actinidiae strains, which cause canker disease in kiwifruit, were collected from kiwifruit orchards in Korea and identified using biochemical and physiological tests. The nucleotide sequences of the 16s rDNA and 16s-23s internally transcribed spacer of the isolates were found to be Identical to those of' the pathotype strain, Kwl 1, of P syringae pv. actinidiae. Remarkably, no coding sequence for phaseolotoxin biosynthesis or phaseolotoxin- resistant ornithine carbamoyltransferase was found by PCR amplification in any of the new Korean isolates of pseudomonas syringae pv. actinidiae, although this was clearly identified in the control pathotype Kwl 1 reference strain. In contrast, three primer sets derived from the coronatine biosynthetic gene cluster and DNA from the Korean strains yielded amplified DNA fragments of the expected size. A sequence analysis of the PCR products revealed that P. syringae pv. actinidiae and the Korean strains of pv. actinidiae contain coronafncate ligase genes (cfl)with identical sequences, whereas their. corR genes exhibited 91% sequence similarity. The production of coronatine, instead of phaseolotoxin, by the Korean strains of P. syringae pv. actinidiae was confirmed by a bioassay using reference pathovars known to produce coronatine and phaseolotoxin. The genes for coronatine biosynthesis in the Korean strains of P. syringae pv. actinidiae were found to be present on plasmids.

• Journal of Microbiology and Biotechnology
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• v.9 no.3
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• pp.334-339
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• 1999

More innovative molecular markers were investigated for rapid and consistent differentiation of Metarhizium anisopliae var. majus from M. anisopliae var. anisopliae. A total of 28 isolates were obtained from various countries and hosts: 13 isolates of M. anisopliae var. anisopliae, 12 isolates of M. anisopliae var. majus, and 3 isolates of M. anisopliae collected in Korea. This study involved restriction enzyme digestions of a PCR product amplified from nuclear internally transcribed spacer (ITS) and a portion of the 28S rDNA regions. Among 11 different restriction enzymes used in this study, MboⅠ digestion particularly produced a restriction pattern that had characteristics of M. anisopliae var. majus. This restriction pattern was consistent in all isolates of M. anisopliae var. majus regardless of their geographic origins and insect hosts. Mapping experiments revealed that MboⅠ sites of M. anisopliae var. majus are identical to those of M. anisopliae var. anisopliae with an exception for the presence of an additional site in the PCR product. Results from this study provide an additional method for identification and differentiation of isolates of these two varieties of M. anisopliae for use in the field and laboratory experiments.

• KSBB Journal
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• v.25 no.6
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• pp.565-571
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• 2010

To develop thermostable ethanol fermentative yeast strain for lignocellulosic simultaneous saccharification and fermentation, high ethanol producing yeast, Saccharomyces cerevisiae CHY1012 and thermostable yeast, Kluyveromyces marxianus CHY1703 were fused by protoplast fusion. The thermostable fusant, CHY1612 was identified as a Kluyveromyces marxianus by phenotypic and physiological characteristics, as well as molecular analysis based on the D1/D2 domains of the large subunit (26S) rDNA gene and the internally transcribed spacer (ITS) 1 + 2 regions. For lignocellulosic ethanol production, AFEX pretreated barley straw at $150^{\circ}C$ for 90 min was used in a simultaneous saccharification and fermentation (SSF) process using thermotolerant CHY1612. The SSF from 16% pretreated barley straw at $43^{\circ}C$ gave a saccharification ratio of 90.5%, a final ethanol concentration of 38.5 g/L, and a theoretical yield of 91.2%. These results show that K. marxianus CHY1612 has potential for lignocellulosic ethanol production through simultaneous saccharification and fermentation with further development of process.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.828-834
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• 2010

An ethanol-producing yeast strain, CHFY0201, was isolated from soil in South Korea using an enrichment technique in a yeast peptone dextrose medium supplemented with 5% (w/v) ethanol at $30^{\circ}C$. The phenotypic and physiological characteristics, as well as molecular phylogenetic analysis based on the D1/D2 domains of the large subunit (26S) rDNA gene and the internally transcribed spacer (ITS) 1+2 regions, suggested that the CHFY0201 was a novel strain of Schizosaccharomyces pombe. During shaking flask cultivation, the highest ethanol productivity and theoretical yield of S. pombe CHFY0201 in YPD media containing 9.5% total sugars were $0.59{\pm}0.01$ g/l/h and $88.4{\pm}0.91%$, respectively. Simultaneous saccharification and fermentation for ethanol production was carried out using liquefied cassava (Manihot esculenta) powder in a 5-l lab-scale jar fermenter at $32^{\circ}C$ for 66 h with an agitation speed of 120 rpm. Under these conditions, S. pombe CHFY0201 yielded a final ethanol concentration of $72.1{\pm}0.27$ g/l and a theoretical yield of $82.7{\pm}1.52%$ at a maximum ethanol productivity of $1.16{\pm}0.07$ g/l/h. These results suggest that S. pombe CHFY0201 is a potential producer for industrial bioethanol production.