• Korean Journal of Microbiology
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• v.16 no.4
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• pp.170-179
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• 1978

By the successive enrichment culture, more than 250 methanol-utilizing bacteria were isolated from various samples such as soil, waste water and sewage. Two strains of which were selected and tentatively identified as Acinetobacter sp. and Pseudomonas sp. experiments were carried out to determine the growth conditions for the higher biomass yield and to demonstrate the difference to protein composition dependent upon carbon sources of these two species. the results were as follows ; 1. the optimum pH was determined as 8 in the both species. The optimum temperature in Acinetobacter sp. was $25^{\circ}C{\sim}30^{\circ}C$ and pseudomonas sp. was $30^{\circ}C-35^{\circ}C$. The optimum initial concentration of mthanol was determined as 1-2% in Acinetobacter sp. and 2-3% in pseudomonas sp. 2. The optimum concnetrations of nitrogen source, micro-elements, and vitamins such as biotin and thiamine-HCl in Acnetobactar sp. were 1g $(NH_4)_3SO4,\;1{\sim}3mg\;Mn^{++},\;4mg\;Fe^{++},\;10{\mu}g\;biotin,\;and\;100{\mu}g$ thiamine-HCl per liter medium. In the Pseudomonas sp., 2g $(NH_4)_3SO4,\;1mg\;Mn^{++},\;trace\;amounts\;of\;Fe^{++},\;5{\mu}g\;biotin,\;and\;100{\mu}g$ thiamine HCl per liter were effective. Maximum biomass yield was 2.5g/l in Acinetobacter sp. and 4.8g/l in Pseudomonas sp. 3. Protein composition of the two strains exhibited that alkai-labile protein was higher than alkali-stable protein. In Pseudomonas sp., the contents of acid soluble fraction and alkali-stable protein of the cells grown in the methanol medium were higher than in sucrose medium. On the other hand, in Acinetobacter sp., alkalilabile protein of the cells grown in sucrose medium was higher than in methanol medium.

• Journal of Environmental Science International
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• v.18 no.11
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• pp.1261-1270
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• 2009

Fifty hydrocarbon-metabolizing microorganisms were isolated from soil samples polluted by the petroleum oils in Gamman-dong, Busan. Among them, strain 2-3A, showing strong emulsification activity, was selected by oil film-collapsing method. This bacterium was identified as Acinetobacter sp. and designated as Acinetobacter sp. 2-3A. The optimum temperature and pH on the growth of Acinetobacter sp. 2-3A were $25^{\circ}C$ and pH 7.0, respectively. The carbon and nitrogen sources for the most effective emulsification activity were 3.0% olive oil and 0.5% peptone, respectively. The 0.15% potassium phosphate was the most effective emulsification activity as a phosphate source. The optimum emulsification activity condition was $20^{\circ}C$, pH 7.0, and 2.0% NaCl. The optimum time for the best production of biosurfactant was 27 hrs. The emulsification stability was maintained at the temperature range from $4^{\circ}C$ to $100^{\circ}C$, pH range from 6.0 to 10.0, and NaCl range from 0% to 10%. For the oil resolvability of the biosurfactant, the residual oils were investigated by gas chromatography. As a result, it was verified that the biosurfactant decreased and decomposed crude oils from $_nC_{10}$ to $_nC_{32}$.

• Korean journal of applied entomology
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• v.40 no.4
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• pp.277-294
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• 2001

Four new and two known species of soil nematodes belonging the order Dorylaimida are described and illustrated. Discolaimium gyeongiens n. sp. is 1.6~1.7 mm long, c=37~41, odontostyle 19~21$\mu\textrm{m}$ long and is characterized by having wider lip region and very short prerectum. Aporcelaimellus donghwaens n. sp. is 2.8~2.9mm long, c=40.0~4.5, odontostyle 19~20$\mu\textrm{m}$ long and is characterized by possessing shorter odontophore, presence of cardiac disc and conoid tail. Labronema korandus n. sp. is 2.2~2.3 mm long, c=68~81, odontostyle 27~28$\mu\textrm{m}$, spicule 61$\mu\textrm{m}$ long and is characterized by having continuous lip region, circular vulva and cylindrical tail. Zalophidera longus n. sp. is 4.1~4.4mm long, c=107~130, spear 80~93$\mu\textrm{m}$ long and is characterized by large sized body, spear and spear extension. Discolaimoides bulbiferous and Diphtherophora communis were reported here for the first time in Korea.

• The Korean Journal of Soil Zoology
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• v.4 no.2
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• pp.89-100
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• 1999

Four new and a known spacies of the order Mononchida were described and illustrated. Iotonchus obtusus sp. n. was 2.8 mm long, a=33, b=4.2, c=61, V=68%, buccal cavity=61${\times}$45 mm, and is characterized by having basally situated dorsal tooth, presence of vulval papillae and in having short, hemispherical tail with thick cuticle at terminus. Miconchus vulvapapillatum sp. . was 2.7-3.6 mm long, a=29-36, b=4.1-4.5, c=18.4-21, V=65-69%, buccal cavity=53-61${\times}$29-33 mm, spicules=132-137 mm, ventromedian supplements 28-31, and was characterized by having 5-8 pre- and post vulval papillae in contiguous series, and three pairs of vulval glands. Clarkus koreanus sp. n. was 1.1-1.3 mm long, a=27.5-28.8, b=3.5-3.9, c=12-14.5, V=60-64%, buccal cavity=24-28${\times}$13.5-15 mm, and was characterized by well offset lip region, amphids situated well below to dorsal tooth apex, and vulva elevated, with vulval flap. Coomansus ulsani sp. n. was 1.2-1.5 mm long, a=23.5-26, b=3.4-3.8, c=13.6-14.8, V=65-68%, buccal cavity=36-39${\times}$21-23 mm and was characterized by well offset lip region and a thin longitudinal ridge on vertical walls of stoma.

• Journal of Aquaculture
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• v.11 no.2
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• pp.231-240
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• 1998

Tetraselmis is widely used as a live food because of its easy handling, high nutrient, large size and wide tolerant range of temperature and salinity. In order to find the optimum Tetraselmis species for mass culture in Korea, five species of this microalgae were examined on size, optimum culture condition ${\textperthousand}$s, $^{\circ}C.$) and nutrient composition. The results obtained were as follows: Among five species of Tetraselmis, T. sp.(Haeundae) was the largest(major axis $17.6{\pm}1.87^{\mu}$m, mean cell volume 727${\mu}$m), and T. sp. (China) the smallest (major axis $14.6{\pm}1.46^{\mu}$m, mean cell volume 625m). Tetraselmis was very eurythermal and euryhaline species. But optimum temperature and salinity for growth were 24~$30^{\circ}C.$ and 27~30${\textperthousand}$, respectively. Among five species of Tetraselmis, T. sp. (China) seemed to be the most tolerant of high temperature over $30^{\circ}C.$, and T. tetrathele of low temperature below $6^{\circ}C.$. In culture density, T. suecica showed the highest growth rate among the among the five species. The cell density of this microalgae attained to $141{\times}10^4$cells/ml at $24^{\circ}C.$ and 30${\textperthousand}$ within 7 days. In chemical composition, crude protein amount was the highest in T. suecica (44.50%), and crude lipid amount it T. sp. (Haeundae, 7.13%). Total essential amino acid amount was the highest in T. sp. (Haeundae, 50.4%) and total polyunsaturated amount in T. sp. (China, 11.7%) The results on growth and chemical composition of five species of Tetraselmis indicated that T. suecica seemed to be the most suitable species for mass culture in Korea.

• Research in Plant Disease
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• v.21 no.3
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• pp.222-226
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• 2015

The chitinase-producing bacterial strain C-1 is one of the key chitinase-producing biocontrol agents used for effective bioformulations for biological control. These bioformulations are mixed cultures of various chitinolytic bacteria. However, the precise identification, biocontrol activity, and the underlying mechanisms of the strain C-1 have not been investigated so far. Therefore, we evaluated in planta biocontrol efficacies of C-1 and determined the draft genome sequence of the strain in this study. The bacterial C-1 strain was identified as a novel Serratia sp. by a phylogenic analysis of its 16S rRNA sequence. The Serratia sp. C-1 bacterial cultures showed strong in planta biocontrol efficacies against some major phytopathogenic fungal diseases. The draft genome sequence of Serratia sp. C-1 indicated that the C-1 strain is a novel strain harboring a subset of genes that may be involved in its biocontrol activities.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2001.05a
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• pp.224-231
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• 2001

Hydrogenated amorphous carbon films were deposited by ERC-PECVD with deposition conditions, such as ECR power, gas composition of methane and hydrogen, deposition time, and substrate bias voltage. The characteristics of the film were analyzed using the AES, ERDA, FTIR. Raman spectroscopy and micro hardness tester. From the results of AES and ERDA, the elements in the deposited film were confirmed as carbon and hydrogen atoms. FTIR spectroscopy analysis shows that the atomic bonding structure of a-C:H film consisted of sp³and sp²bonding, most of which is composed of sp³bonding. The structure of the a-C:H films changed from CH₃bonding to CH₂or CH bonding as deposition time increased. We also found that the amount of dehydrogenation in a-C:H films was increased as the bias voltage increased. Raman scattering analysis shows that integrated intensity ratio (I/sub D//I/sub G/) of the D and G peak was increased as the substrate bias voltage increased, and films hardness was increased.

• Journal of Environmental Health Sciences
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• v.11 no.1
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• pp.15-28
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• 1985

In order to analyze the water quality in artificial lakes in Chonnam area, a chemical and biological examination of Dongbock Lake and Changsung Lake was conducted from September to December 1983 and May 1984. A summary of the surveyed results is as follows 1. In Dongbock Lake, pH ranged from 7.2-8.1, D.O.: 8.2-12.6mg/l, B.O.D.: 4.4-22.1 mg/l, C.O.D.: 1.0-3.4rag/l, Cl$^-$: 5.9-11.9mg/l, Total-P: 0.001-0.071 mg/l, and Total -N: 0.016-0.697 mg/l, respectively. 2. In Changsung Lake, pH ranged from 7.2-8.1, D.O.: 8.1-9.8mg/l, B.O.D.: 0.9-2.9mg/l, C.O.D.: 1.9-3.4mg/l. Total- P: 0.006-0.016mg/l and Total -N:0.006-0.033mg/l, respectively. 3. The Phytoplankton identified in this investigation were distributed in a total of 46 genera and 76 spedes in Dongbock Lake 37 genera and 45 species in Changsung Lake. 4. In Dongbock Lake, it was found that the dominant algae were Melosira sp., Microcystis sp. and Synedra sp. in September Melosira sp. and Microcytis sp. in October, but Cymbella sp., Naviculla sp. and Nitzschis sp. were also observed in OctoberAsterionella sp., Melosira sp. and Microsystis sp. in November and Melosira sp., Asterionella sp sp. and Synedra sp. in December 1983. 5. In Changsung Lake, it was found that the dominant algae were Melosira sp., Lyngrbya sp. and Microcystis in September Melosira sp. and Synedra sp. in October and November and Melosira sp., Lyngbya sp. and Asterionella sp. in December 1983. The dominant algae were Melosira sp., Lyngbya sp. and Euglena sp. in May 1984. 6. It was found that the dominant algae in both Dongbock and Changsung Lakes were Microcystis sp., Melosira sp. and Asterionella sp.. Which are strongly related with water-bloom. Therefore, it could be suggested that the eutrophication phenomena is going to occur very easily in Dongbock Lake and possibly in Changsung Lake.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.466-472
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• 1997

Peptides separated from fish paste washing liquid of an Alaska pollak (Theragria chalcogramma) were purified and characterized. The fish paste washing liquid (supernatant) was separated by centrifugation of fish paste homogenate. The fish paste washing liquid of $0.5\%$ concentration was hydrolyzed for 24 hour at $50^{\circ}C$ by immobilized protease in bioreactor and decomposing liquid of protein having $50\%$ decomposing rate (OPA method) was obtained. The crude peptide fractions were obtained from this liquid by Dowex 50w $(H^+)$ column chromatograpy. Purified peptides (SP-fraction peptides) were fractionated by using SP-Sepadex C-25 $(H^+)$ column chromatography. Molecular weights and amino acid compositions of these peptides were estimated by Sephadex G-50 column chromatography and HPLC, respectively. when the washed peptides was eluated with $0.6\~0.9\%\;and\;1.2\~2.0\%$ of NaCl, peptides composed of weakly basic amino acids and strongly basic amino acid were respectively eluted. Molecular weights of each peptide fractions showed the broad distribution from 1,000 Da to 3,000 Da in the order of SP-4>SP-3>SP-2>SP-1. Peptides contained a large quantity of glycine, arginine, glutamic acid, and alanine in the washed peptide and its SP-tractions, respectively.

• Journal of Microbiology and Biotechnology
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• v.34 no.7
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• pp.1475-1483
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• 2024

Three Gram-stain-positive, aerobic, rod-shaped, and non-motile bacteria, labelled as W11^T, SW19^T, and YR1^T, were isolated from soil, and performed their polyphasic taxonomic investigation. The phylogenetic and 16S rRNA gene sequence analysis showed that strains W11^T, SW19^T, and YR1^T belonged to the genera Agromyces, Rathayibacter, and Nocardioides, respectively. Strain W11^T was closely affiliated with Agromyces cavernae SYSU K20354^T (98.1%), strain SW19^T showed the closest affiliation with Rathayibacter rubneri ZW T2_19^T (97.0%), and strain YR1^T was most closely related to Nocardioides marmorisolisilvae KIS18-7^T (98.0%). The genome sizes of strains W11^T, SW19^T, and YR1^T were 4,181,720 bp, 4,740,677 bp, and 4,228,226 bp, respectively, with DNA G+C contents of 70.5%, 64.2%, and 69.7%, respectively. Average nucleotide identity and digital DNA-DNA hybridization values of W11^T, SW19^T, and YR1^T with their respective reference species were <79.6% and <23.6%, respectively. The predominant cellular fatty acids detected in strain W11^T were anteiso-C_15:0, iso-C_16:0, and anteiso-C_17:0. In strain SW19^T, they were summed feature 9 (C_16:0 10-methyl and/or iso-C_17:1ω 9c), anteiso-C_17:0, and anteiso-C_15:0. Strain YR1^T exhibited C_18:1ω 9c, C_18:0 10-methyl, TBSA, and anteiso-C_15:0 as its major cellular fatty acids. Overall, the polyphasic taxonomic comparisons indicated that strains W11^T, SW19^T, and YR1^T represent novel species within the genera Agromyces, Rathayibacter, and Nocardioides, respectively. Accordingly, we propose the names Agromyces silvae sp. nov., with the type strain W11^T (=KCTC 49818^T =NBRC 115999^T), Rathayibacter soli sp. nov., with the type strain SW19^T (=KCTC 49860^T =NBRC 116108^T), and Nocardioides terrisoli sp. nov., with the type strain YR1^T (=KCTC 49863^T =NBRC 116165^T).