• Proceedings of the Microbiological Society of Korea Conference
• /
• 2003.05a
• /
• pp.26-33
• /
• 2003

We isolated and identifed culturable Arctic bacteria that have inhabited around Korean Arctic Research Station Dasan located at Ny-Alsund, Svalbard, Norway $(79^{\circ}N,\;12^{\circ}E)$. The pure colonies were inoculated into nutrient liquid media, genomic DNA was extracted, and phylogenetic analysis was performed on the basis of 16S rDNA sequences. Out of total 227 strains, 198 strains were overlapped or unidentified, and 43 bacteria were finally identified: 31 strains belonged to Pseudomonas, 7 strains Arthrobacter, two Flavobacterium sp., an Achromobacter sp., a Pedobacter sp., and a Psychrobacter sp. For isolation of diverse bacteria, we need more effective transport method than 3M petri-films, which were used for convenience of transportation that was restricted by volume. We also need to use other culture media than nutrient media. We expect these Arctic bacteria can be used for screening to develop new antibiotics or industrial enzymes that are active at low temperature.

• Journal of Microbiology and Biotechnology
• /
• v.7 no.1
• /
• pp.43-48
• /
• 1997

Three strains capable of degrading a chlorophenol were isolated by selective enrichment from soils contaminated with industrial wastewater. A Pseudomonas solanacearum TCP114 could use 2,4,6-trichlorophenol (TCP) as sole carbon and energy source, while two strains of Pseudomonas testosteroni CPW301 and Arthrobacter ureafaciens CPR706 could use 4-CP. All isolates also grew well on phenol. The degradation of one component by a pure strain was strongly affected by the presence of other compounds in the medium, CPW301 and CPR706 entirely lost the ability to degrade 4-CP and phenol in the presence of TCP. TCP114 also lost the ability to degrade phenol when 4-CP was added to the culture medium. These restrictions on the degradability could be overcome by employing defined mixed cultures (TCP114 and one strain of 4-CP degrading strains). All three components were successfully degraded by defined mixed cultures through their cooperative activities. It was also demonstrated that defined mixed cultures could be immobilized by using calcium alginate for the semi-continuous degradation of the three component mixture. Immobilization could not only accelerate the degradation rate, but also allowed the reuse of the cell mass several times without loss of the cells' degrading capabilities.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 2000.04a
• /
• pp.100-107
• /
• 2000

In a recently developed strategy for in-situ treatment of polychlorinated biphenyls (PCB), bioaugmentation was used in conjunction with a surfactant, sorbitan trioleate, as a carbon source for the degrader bacteria, along with the monoterpene, carvone, and salicylic acid as inducing substrates. Two bacteria were used for soil inoculants, including Arthrobacter sp. st. B1B and Ralstonia eutrophus H850. This methodology achieved 60% degradation of PCBs in Aroclor 1242 after 18 weeks in soils receiving 34 repeated applications of the degrader bacteria. However, an obvious limitation was the requirement for soil mixing after every soil inoculation. In the research reported here, bioaugmentation and biostimulation treatment strategies were modified by using the earthworm, Pheretima hawayana, as a vector for dispersal and mixing of surface-applied PCB-degrading bacteria and soil chemical amendments. Changes in microbial biomass and microbial community structure due to earthworm effects were examined using DNA extraction and PCR-DGGE of 16S rDNA. Results showed that earthworms effectively promoted biodegradation of PCBs in bioaugmented soils to the same extent previously achieved using physical soil mixing, and had a lesser, but significant effect in promoting PCB biodegradation in biostimulated soils treated with carvone and salicylic acid. The effects of earthworms were speculated to involve many interacting factors including increased bacterial transport to lower soil depths, improved soil aeration, and enhanced microbial activity and diversity.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.6
• /
• pp.1013-1020
• /
• 1997

The cellular fatty acids of 47 marine bacteria representing the genus Alteromonas, Arthrobacter, Bacillus, Micrococcus, Pseudomonas, Shewanella, Staphylococcus and Stenotrophomonas were determined by a gasliquid chromatographic analysis. Sixty-eight different fatty acids with 10 to 20 carbon atoms were detected in marine bacteria. Of the eight genus examined, 14:0, 16:0 and i17:0 were detected in all, while i14:0, a15:0, i16:0, and 15:0 were found in most of all. There were significant differences in the fatty acid patterns between Gram positive and Gram negative bacteria. Bacteria of Gram positive genus showed relatively high contents of the branched type fatty acids, while the major fatty acids in Gram negative were unsaturated and straight forms. Phylogenetic relationships between marine bacteria defined by the cellular fatty acid patterns represented obvious differences between Gram positive and Gram negative genera, even in respective genus. Therefore, the bacterial classification and identification can be accomplished more easily and rapidly based on the cellular fatty acid profiles than the conventional methods.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.3
• /
• pp.385-389
• /
• 2012

The application of microorganisms in the field of construction material is rapidly increasing worldwide; however, almost all studies that were investigated were bacterial sources with mineral-producing activity and not with organic substances. The difference in the efficiency of using bacteria as an organic agent is that it could improve the durability of cement material. This study aimed to assess the use of biofilm-forming microorganisms as binding agents to increase the compressive strength of cement-sand material. We isolated 13 alkaliphilic biofilmforming bacteria (ABB) from a cement tetrapod block in the West Sea, Korea. Using 16S RNA sequence analysis, the ABB were partially identified as Bacillus algicola KNUC501 and Exiguobacterium marinum KNUC513. KNUC513 was selected for further study following analysis of pH and biofilm formation. Cement-sand mortar cubes containing KNUC513 exhibited greater compressive strength than mineral-forming bacteria (Sporosarcina pasteurii and Arthrobacter crystallopoietes KNUC403). To determine the biofilm effect, Dnase I was used to suppress the biofilm formation of KNUC513. Field emission scanning electron microscopy image revealed the direct involvement of organic-inorganic substance in cement-sand mortar.

• Journal of Microbiology and Biotechnology
• /
• v.13 no.2
• /
• pp.251-255
• /
• 2003

The bacterial compositions of seven hot-pepper sown soil were compared in this study. From the 624 isolates, 95 species and 49 genera were identified by fatty acid methyl ester analysis (FAME). The FAME results of seven soil showed two distinct clusters for aerobic and Gram-negative bacteria in the high productivity and monoculture soil samples. While Arthrobacter ($17\%$), Kocuria ($11\%$), Pseudomonas ($8\%$), and Bacillus ($8\%$) were predominant among bacteria which were cultured on heterotrophic (YG) agar medium, Pseudomonas ($56\%$), Stenotrophomonas ($16\%$), and Burkholderia ($8\%$) were predominant on crystal violet agar medium. Shannon Weaver indices (H) indicated that colonies obtained from heterotrophic agar medium (3.1) were found to be more diverse than those obtained from the crystal violet media (1.9). The results suggest that FAME analysis may be a potential indicator for of soil quality.

• YAKHAK HOEJI
• /
• v.21 no.3
• /
• pp.167-171
• /
• 1977

A new assay method for delta-l-dehydrogenated-3-ketoco-rticosteroid in the presence of proteinous material or whole-cell-enzyme and 3-ketocorticosteroid has been developed. This method makes use of the linear relationship between the ratio of absorbances at 265 nm and at 242 nm and the fractional concentration of delta-1-3-ketosteroid. Theoretical values were calculated based on the absorbances of proteinous material at fixed concentrations of the 3-ketosteroid and delta-1-dehydrogenated-3-ketosteroid. The values obtained experimentally showed good agreement with the values obtained experimentally showed good agreement with the values theoretically predicted. The new assay method developed for the steroid mixtiure containing proteinous material is of some practical importance. The use of such assay method enables one to determine the enzyme activity and the rate of enzyme reaction or conversion rather quickly, easily and accurately. By the use of this assay method, the reaction kinetics of whole-cell-enzyme has also been studied. It was found that it followed the simple Michaelis-Menten type enzyme kinetics. Also the reversibility of this reaction with actively metabolizing cell was examined. It was found that delta-l-dehydrogenated-3-ketosteroid could not be hydrogenated reversibly to 3-ketosteroid by this enzyme system.

• Journal of Species Research
• /
• v.10 no.2
• /
• pp.99-116
• /
• 2021

In 2018, as a subset study to discover indigenous prokaryotic species in Korea, a total of 18 unreported bacterial strains were discovered. From the high 16S rRNA gene sequence similarity (>98.8%) and formation of a robust phylogenetic clade, it was determined that each strain belonged an independent and predefined bacterial species. There were no official report that these 18 species were previously described in Korea; therefore, one strain of Williamsia, one strain of Rhodococcus, three strains of Microbacterium, three strains of Agromyces, one strain of Arthrobacter, one strain of Paeniglutamicibacter, one strain of Pseudarthrobacter, one strain of Nocardioides, one strain of Fibrella, one strain of Hymenobacter, one strain of Deinococcus, two strains of Fictibacillus, and one strain of Paenibacillus are described as unreported bacterial species in Korea. Gram reaction, basic biochemical characteristics, and colony and cell morphologies are described in the species description section.

• Journal of Species Research
• /
• v.11 no.1
• /
• pp.1-9
• /
• 2022

The phylum Actinobacteria includes many groups of aerobic, Gram-stain-positive, rod, or filamentous shaped bacteria. Actinobacteria are known for multicellular differentiation in some groups, and also for production of various secondary metabolites such as antibiotics. During a series of extensive surveys of indigenous prokaryotic species diversity in Korea, bacterial strains belonging to Actinobacteria were isolated from various sources of terrestrial environments. A total of 21 bacterial strains, belonging to 10 genera in 8 families, were isolated as unrecorded species in Korea. Among them, 11 were assigned to the family Streptomycetaceae, two species assigned to each of the families Microbacteriaceae, Mycobacteriaceae and Nocardioidaceae, and one species assigned to each of the families Euzebyaceae, Corynebacteriaceae, Micrococcaceae and Intrasporangiaceae. At the genus level, Streptomyces (10 species) was the most abundant, followed by Microbacterium and Mycolicibacterium(2 species each), and one species in each of the genera Corynebacterium, Euzebya, Arthrobacter, Terracoccus, Kribbella, Nocardioides and Yinghuangia. The detailed descriptions of each unrecorded species are provided.

• Korean Journal of Environmental Biology
• /
• v.40 no.4
• /
• pp.442-454
• /
• 2022

A total of 31 bacterial strains were isolated from the Geum River basin in the Republic of Korea during our investigation of indigenous prokaryotic species. The isolated bacterial strains had high 16S rRNA gene sequence similarity (>98.7%) with those of validly published bacterial species, which have not been reported in Republic of Korea. The 31 bacterial strains were phylogenetically diverse and assigned to 4 phyla, 8 classes, 18 orders, 21 families, and 27 genera. At the genus level, the unreported species were affiliated with Kineococcus, Pedococcus, Rhodoluna, Salinibacterium, Rhodoluna, Arthrobacter, Williamsia, Nakamurella, Nocardioides of the class Actinobacteria, Patulibacter of the class Thermoleophilia, Pontibacter, Hymenobacter of the class Cytophagia, Flavobacterium of the class Flavobacteriia, Geomicrobium of the class Bacilli, Brevundimonas, Gellertiella, Rhizobium, Paracoccus, Taonella, Sphingomonas of the class Alphaproteobacteria, Burkholderia, Polaromonas, Hydrogenophaga, Chitinilyticum, Azospira, Zoogloea of the class Betaproteobacteria, and Pseudomonas of the class Gammaproteobacteria. The unreported bacterial species were further characterized by examining their morphological, cultural, physiological, and biochemical properties. The detailed descriptions of the 31 bacterial strains were provided.