• Microbiology and Biotechnology Letters
• /
• v.28 no.2
• /
• pp.92-96
• /
• 2000

Aspergillus sp. F184 was isolated from soil for the development of new xanthine oxidase inhibitor. This xanthine oxidase inhibitor was sequentially purified by filtration, HP-20 adsorption column chromatography, ethyl acetate extraction, silica gel column chromatography and crystallization, and was named as YUX 104. YUX 104 was identified to be 5,6-epoxy-2-hydroxy-3-methyl-2-cyclohexene-1,4-dione(terreic acid) by NMR and mass spectroscopic sudies.

• Journal of Aquaculture
• /
• v.11 no.3
• /
• pp.345-352
• /
• 1998

The effect of starvation on the growth and hepatocyte nuclear size of larval rockfish Sebastes schlegeli and spotted sea bass Lateolabrax sp. were studied. The growth of total length and wet weight in both rockfish and spotted sea bass starved were lower than their control counter-parts. The nuclei sizes of parenchymal cells in the liver of rockfish and spotted sea bass were correlated with the nutritional status of their first-feeding larvae. The result suggested that hepatocyte nuclear size in rockfish and spotted sea bass could be used as an alternative indicator for the identification of starving condition and such karyometry might be criteria for evaluating the successful transition from endogenous to exogenous feeding regime.

• Journal of Life Science
• /
• v.23 no.5
• /
• pp.669-675
• /
• 2013

The stability of monascus pigment produced by Monascus sp. MK2 was investigated according to light, pH, temperature, organic acid, synthetic antioxidant, and natural substance. The light stability was increased (sun light < fluorescent lamp < ultraviolet rays < dark condition) when storing the monascus pigments. Although the monascus pigments were stable in the range of pH 3.0, the degradation rate of pigment was increased at pH 11.0. The stability of monascus pigment gradually decreased as temperature increased. In addition, pigment stability was increased by adding the synthetic antioxidant and natural substance.

• Korean Journal of Microbiology
• /
• v.50 no.4
• /
• pp.381-383
• /
• 2014

In the course of screening for ${\alpha}$-glucosidase inhibitor produced by microorganism, the active compound was isolated from the culture filtrate of Bacillus sp. SKU31-1 using a series of chromatography procedures. The structure of the active compound was elucidated as 5-amino-1-hydroxymethyl-1, 2, 3, 4-cyclohexanetetrol on the basis of spectroscopic evidence obtained and comparison with data from the literature. The active compound showed potent inhibitory activity against ${\alpha}$-glucosidase with an $IC_{50}$ value of $1.9{\mu}M$ for maltose and 4.9 mM for sucrose. A Lineweaver-Burk plot indicated that its inhibition of ${\alpha}$-glucosidase was competitive, with a $K_i$ value of 0.15 mM.

• Cement
• /
• s.81
• /
• pp.41-54
• /
• 1980

• Cement
• /
• s.63
• /
• pp.15-23
• /
• 1976

• The Korean Journal of Soil Zoology
• /
• v.9 no.1_2
• /
• pp.1-5
• /
• 2004

Insect pests and their natural enemies of Hibiscus Linne (Malvaceae) were investigated from March 2002 to November 2004. Fourteen insect pest species of 9 families in 5 orders were collected from Hibiscus syriacus: 5 species in Homoptera, 3 species in Lepidoptera, 2 species in Coleoptera, 1 species in Orthoprera, 1species in Hemiptera, 1 spedies in Acarina, and 1 species in Stylommatophora. Especially, Aphis gossypii Glover (Aphididae), Anomis megogona Walker(Noctuidae) and Tetranychus urticae Koch (Tetranychidae) were very important species because of their increasing daminge. The highest donsities were observed from May to June in August in Tetranychus urticae. As the enemies and ento-mopathogens of insect pests on Hibiscus syriacus, 1 species of bacteria, 3 species of fungi, 1 species of fungi, 1 species of Hemiptera, 1 species of Coleoptera, 2 species of Hymenopetera, 2 species of Diptera, and 1 species of Acarina were investigated. As the predators and parasitoids of Aphis gossypii, Aphidoletes aphidoletes aphidimyza Rondani (Cecidomyiidae), Meliscaeva cinctella Zetterstedt (Syrphidae), Harmonia axyridis Pallas (Coccinellidae), and Aphidius gifuensis Ashmead (Braconidae), entomopathogenic fungi, Vericillium lecani naturalis strain (Moniliaceae) and Beauveria bassiana naturalis strain strain (Hypocreaceae) were observed and Bacillus thuringiensis naturalis strain (Bacillaceae), B. bassiana, Metarhizium anisopliae naturalis strain (Hypocreaceae), predators of Tetranychus urticae, Amblyseius sp. (Phytoseiidae), and Orius sp. (Anthocoridae) were observed.

• Microbiology and Biotechnology Letters
• /
• v.32 no.2
• /
• pp.172-178
• /
• 2004

This research is performed for a biological control of Chinese cabbage clubroot, we isolated an antagonistic bacterium AC-3 against Plasmodiophora sp., causal pathogens of cabbage clubroot. The isolated strain was identified as Streptomyces sp. by culture morphology, biochemical reactions, and homology research based on l6S rDNA sequences. Streptomyces sp. AC-3 produced chitinase (9.3 units/$m\ell$) in culture broth. So Plasmodiophora sp. mycelia changed abnonnal swelling, curling and branching mycelia by Streptomyces sp. AC-3 culture. In a field infected by Plasmodiophora sp., the treatment of a organic fertilizer added 2% Streptomyces sp. AC-3 microbial inoculant, it resulted in about 50% reducing the severity of cabbage clubroot significantly on cabbage plants compared with treated organic fertilizer plants. Additional disease such as sclerotinia rot, fusarium wilt and pythium rot were also significantly reduced by the treatment of the organic fertilizer added Streptomyces sp. AC-3 microbial inoculant.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.6 no.3
• /
• pp.180-189
• /
• 2001

This study was conducted to investigate the macrobenthic community in Ulsan Bay and Onsan Bay, in November of 1997. The density of benthic animals was 535 md./m2, and the number of species was 117. Polychaeta was the most dominant faunal group, comprising a total of 63 species, and its density was 380 md./m2 The most dominant benthic macrofauna was Cirratulrus cirratulas (2.7%), and followed by Tharyx sp. (16.6%), Ruditapes philippinarum (16.1%), Lumbrineris longifolia (10.3%) and so on. The dominant species occupied their distinct unique distribution area. Tharyx sp., R. philippinarum and Grandidierella sp.1 occurred mainly in Ulsan Bay, L. longifolia and Euchone sp. in Onsan Bay, and C. cirratulas and Cirriforimia tentaculata in both bays. By cluster analysis, study area was divided into 4 station groups: Northern Ulsan Bay (Al), the middle area of Ulsan Bay (Bl), offsea area between Ulsan Bay and Onsan Bay (Bll), and Onsan Bay (C). Northern Ulsan Bay was characterized by low species number and high density. The dominant species were C. cirratulas R. philippinarum and Tharyx sp. The middle area of Ulsan Bay was by low species number and density, and its characteristic species was Grandidierella sp.1. The offsea area between Ulsan and Onsan Bay was by high species number and low density. Onsan Bay was by high species number and high density, and its important species were L. longifolia and Euchone sp.

• Journal of Life Science
• /
• v.32 no.10
• /
• pp.778-783
• /
• 2022

This study isolated a new agarase-producing bacterium and characterized its agarase. A new agar-degrading strain was isolated from the seashore of Namhae in Gyeongnam province, Korea, and was purely cultured using the Marine Agar 2216 media. The isolated bacterium was identified as Simiduia sp. SH-2 after 16S rRNA gene sequencing. The crude agarase was obtained from the culture medium of the Simiduia sp. SH-2 strain, and the agar-degrading activity was measured. The highest level of activity of the Simiduia sp. SH-2-derived agar-degrading enzyme was 625 U/l. Agar degradation activity was most significant at 40℃ and pH 7.0. Compared to the activity at 40℃, the relative activity was 31% at 20℃ and 71% at 30℃. Compared to the activity at pH 7.0, the relative activity was 94% and 89% at pH 6.0 and pH 8.0, respectively. Residual activity was greater than 96% after exposure to 20℃ and 30℃ for 2 hr and more than 49% after exposure to 40℃ for 2 hr. Simiduia sp. SH-2 was identified as a strain producing β-agarase that creates neoagarooligosaccharides, such as neoagarotetraose and neoagarohexaose. Therefore, the Simiduia sp. SH-2 strain and its β-agarase are expected to be useful functional material producers in the food, cosmetic, and pharmaceutical industries.