• Journal of fish pathology
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• v.26 no.2
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• pp.77-88
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• 2013

Starry flounder, Platichthys stellatus (body length $4.4{\pm}0.51cm$) that became sick during an outbreak of disease at mariculture facilities at Ulsan, Korea in August of 2012, were examined to identify the cause of the disease. Diseased fish didn't show a unique sign, but the oxidase-positive and gram negative rod was isolated from moribund fish. The bacterium was revealed as Photobacterium damselae subsp. piscicida by biochemical analysis and sequence analysis of the 16S rRNA and capsular polysaccharide (CPS) genes. The isolates (AD5) was carrying susceptible to ofloxacin and gentamycin and showed high growth value at $18^{\circ}C$ and $25^{\circ}C$ compared to four other P. damsela strains.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.31-32
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• 2005

Neoagaro-oligosaccharides are produced only by enzymatic degradation of agarose by ${\beta}-agarase.^{1)}$ Neoagaro-oligosaccharides inhibit the growth of bacteria, slow the rate of degradation of starch, are used as low-calorie additives to improve food quality, and have macrophage-stimulating activity. Furthermore, neoagarobiose is a rare reagent that has both moisturizing effect on skin and whitening effect on melanoma $cells.^{2)}$ An agar-degrading marine bacterium was isolated from the sea water at the northeast coast in Cheju island, Korea. The strain was gram negative, aerobic, and motile rod. The 16S rRNA of the strain had the closest match of 98% homology, with that from Agarivorans albus. On the basis of several phenotypic characters and a phylogenetic analysis, this strain was designated Agarivorans sp. JA-1. In solid agar plate, Agarivorans sp. JA-1 produced a diffusible agarase that caused agar softening around the colonies. Agarivorans sp. JA-1 was cultured for 36 hr in marine broth 2216 (Difco, USA) and the supernatant that containing an extracellular ${\beta}-agarase$ was prepared by centrifugation of culture media. The enzyme exhibited relatively strong activity at $40^{\circ}C$ and was stable up to $60^{\circ}C$. Using PCR primers derived from the ${\beta}-agarase$ gene of Vibrio sp., the gene encoding ${\beta}-agarase$ from Agarivorans sp. JA-1 was cloned and sequenced. The structural gene consists of 2931 bp encoding 976 amino acids with a predicted molecular weight of 107,360 Da. The deduced amino acid sequence showed 99% and 34% homology to $agaA^{2)}$ and $agaB^{2)}$ genes for ${\beta}-agarase$ from Vibrio sp., respectively. The expression plasmid for ${\beta}-agarase$ gene of Agarivorans sp. JA-1 is being constructed and the recombinant enzyme will be biochemically characterized.

• Korean Journal of Veterinary Research
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• v.33 no.1
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• pp.93-99
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• 1993

This study was conducted to investigate the cause of a new duck disease occured in southern part of Korea. A meat type duck farm located in Kangjin, Chonnam Province had experienced outbreaks of septicemic disease at around 20 days of age in nearly every batch of ducklings from early spring to early summer in 1989. Main symptoms of the birds were eye and nasal discharge, depression, inappetence, diarrhea and nervous signs such as tremor and ataxia. Some birds died suddenly without any signs. Mortality reached from 20% to 80% in severe cases. The autopsy findings of the affected ducklings revealed consistantly severe airsacculitis, fibropericarditis, perihepatitis and occasionaly enteritis and distended ureter with urate deposit. A rod shaped gram-negative bacterium was isolated purely from brain and liver of the diseased ducks by culturing the specimens on blood agar for 48 hours in candle jar. The isolate neither produced hemolysis nor grew on MacConKey Agar. It formed colony relatively slowly being recognizable at least 36 hours after culturing, reaching colony size of about 1mm in diameter at 48 hours culture. The colony looked iridescent under oblique light and had muddy odor. The isolate did not ferment carbohydrates tested but produced gelatinase, hippuricase and oxidase which were considered as characteristics of P anatipestifer. The isolate induced similar signs and lesions when infected experimentally into ducks of 3 to 38 days age via intraperitoneum or intratrachea. However it did not produce any clinical signs wen inoculated via intranasal route. It produced only mild signs in chicken just injected with a very large dose. The bacteria did not produce any signas or lesions in mice. It was concluded through biochemical and physiological tests and animal inoculation tests that the new disease was caused by P anatipestifer.

• The Plant Pathology Journal
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• v.24 no.2
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• pp.207-210
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• 2008

In March of 2003, tumors (galls) were observed on ginseng seedling roots in ginseng seedbeds at Yeoju, Gyeonggi province, Korea. Symptoms were spherical or galls with about 0.5-1.0cm in diameter formed on the upper through middle parts of the primary roots. Bacterial isolates obtained from the root galls were Gram-negative, rod-shaped with peritrichous flagella, aerobic, not forming yellow or orange colonies on nutrient glucose agar, yeast extract-dextrose $CaCO_3$ agar and nutrient-broth yeast extract agar, non-fluorescent on King's B agar, and non-spore forming, which were identical to characteristics of the genus Agrobacterium. They were identified as Agrobacterium tumefaciens with 0.732-0.993 similarities in 100% probability by the Biolog analyses. The 16S rRNA gene partial sequences of the six isolates tested (Genbank Accession EF486308-EF486313) were 100% homologous to those of other A. tumefaciens strains (GenBank accession AF501343, AY701900, AY701898, AY701899). The above results confirmed that this bacterium is A. tumefaciens. Pathogenicity of the bacteria was proved by the inoculation test on carrot root discs and tomato seedlings. This is the first description of A. tumefaciens causing root gall in ginseng seedling. The disease occurred locally and sparsely, but considering its appearances in seedbeds suggests that the ginseng root gall may become a threat to ginseng in Korea.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1134-1141
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• 2004

A bacterial strain capable of hydrolyzing sulfate ester bonds in p-nitrophenyl sulfate and agar was isolated from the Southeast coast of Korea. The isolated strain (AS6330) is aerobic, Gram-negative, rod-shaped, and motile. Octadecanoic acid was the major cellular fatty acid in the isolate. An almost complete 16S rDNA sequence of the isolate was determined and the sequence similarity of the 16S rDNA with those of known Sphingomonas spp. was found to be at most $96.4\%$, implying that the isolate was a new Sphingomonas species. The organism was grown optimally at NaCl concentration of $1.5-3.5\%$. Optimum culture conditions were determined to be $30^{\circ}C$ and pH 7.0 for 48 h fermentation using a laboratory fermentor under constant culture conditions. Partially purified arylsulfatase through Q-Sepharose and phenyl­Sepharose chromatographies catalyzed hydrolysis of sulfate ester bonds in agar, and $97\%$ of sulfates in agar were removed after 4 h reaction at $45^{\circ}C$ and pH 7.0. The arylsulfatase from the isolated bacterium might be useful for the removal of sulfate groups in agar.

• Journal of Microbiology and Biotechnology
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• v.26 no.9
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• pp.1586-1592
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• 2016

Klebsiella pneumoniae is a gram-negative, non-motile, rod-shaped, and encapsulated bacterium in the normal flora of the intestines, mouth, skin, and food, and has decarboxylation activity, which results in generation of diamines (cadaverine, agmatine, and putrescine). However, there is no specific information on the exact mechanism of decarboxylation in K. pnuemoniae. Specifically lysine decarboxylases that generate cadaverine with a wide range of applications has not been shown. Therefore, we performed a functional study of lysine decarboxylases. Enzymatic characteristics such as optimal pH, temperature, and substrates were examined by overexpressing and purifying CadA and LdcC. CadA and LdcC from K. pneumoniae had a preference for L-lysine, and an optimal reaction temperature of 37℃ and an optimal pH of 7. Although the activity of purified CadA from K. pneumoniae was lower than that of CadA from E. coli, the activity of K. pneumoniae CadA in whole cell bioconversion was comparable to that of E. coli CadA, resulting in 90% lysine conversion to cadaverine with pyridoxal 5'-phosphate L-lysine.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.1
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• pp.67-74
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• 2004

A bacterium which grow on phenol as an only carbon and energy source was isolated from the sewage sludge at Nangi municipal wastewater treatment plant in Seoul. This bacterium was found to be a Gram negative rod with high motility, and well grew on 0.05%, 0.1%, and 0.15% of phenol. No matching strain was found from the result of the BBL test. Phylogenetic analysis of the strain by comparison of the 16s-rDNA has revealed that this bacterium has 99% of similarity with Stenotrophomonas maltophilia strain of Xanthomonas group, which belongs t the Gamma (${\gamma}$) subdivision of Proteobacteria. This strain has also shown 98% of similarity with nitrogen fixing bacterium MAGDE3 and Pseudomonas cissicola strain, and 97% of similarity with Stenotrophomonas sp. LMG198 and Xanthomonas cucurbitae.

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.15-20
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• 2010

A Gram negative, aerobic, nonspore-forming, straight or curved rod-shaped bacterium, designated Gsoil $317^T$, was isolated from soil of a ginseng field in Pocheon Province (South Korea) and was characterized using a polyphasic approach. Cells were dimorphic, with stalk (or prostheca) and nonmotile or nonstalked and motile, by means of a single polar flagellum. Comparative analysis of 16S rRNA gene sequences revealed that strain Gsoil $317^T$ was most closely related to Caulobacter mirabilis LMG $24261^T$ (97.2%), Caulobacter fusiformis ATCC $15257^T$ (97.1 %), Caulobacter segnis LMG $17158^T$ (97.0%), Caulobacter vibrioides DSM $9893^T$ (96.8%), and Caulobacter henricii ATCC $15253^T$ (96.7%). The sequence similarities to any other recognized species within Alphaproteobacteria were less than 96.0%. The detection of Q-10 as the major respiratory quinone and a fatty acid profile with summed feature 7 ($C_{18:1}\;{\omega}7c$ and/or $C_{18:1}\;{\omega}9t$ and/or $C_{18:1}\;{\omega}12t;$ 56.6%) and $C_{16:0}$ (15.9%) as the major fatty acids supported the affiliation of strain Gsoil $317^T$ to the genus Caulobacter. The G+C content of the genomic DNA was 65.5 mol%. DNA-DNA hybridization experiments showed that the DNA-DNA relatedness values between strain Gsoil $317^T$ and its closest phylogenetic neighbors were below 11%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil $317^T$ should be classified as representing a novel species in the genus Caulobacter, for which the name Caulobacter ginsengisoli sp. novo is proposed. The type strain is Gsoil $317^T$ (=KCTC $12788^T=DSM\;18695^T$).

• Journal of Microbiology and Biotechnology
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• v.23 no.11
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• pp.1617-1626
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• 2013

The Bacterial community structure and its complexity of the enrichment culture during the isolation and screening of imidacloprid-degrading strain were studied using denaturating gradient gel electrophoresis analysis. The dominant bacteria in the original tea rhizosphere soil were uncultured bacteria, Rhizobium sp., Sinorhizobium, Ochrobactrum sp., Alcaligenes, Bacillus sp., Bacterium, Klebsiella sp., and Ensifer adhaerens. The bacterial community structure was altered extensively and its complexity reduced during the enrichment process, and four culturable bacteria, Ochrobactrum sp., Rhizobium sp., Geobacillus stearothermophilus, and Alcaligenes faecalis, remained in the final enrichment. Only one indigenous strain, BCL-1, with imidacloprid-degrading potential, was isolated from the sixth enrichment culture. This isolate was a gram-negative rod-shaped bacterium and identified as the genus Ochrobactrum based on its morphological, physiological, and biochemical properties and its 16S rRNA gene sequence. The degradation test showed that approximately 67.67% of the imidacloprid (50 mg/l) was degraded within 48 h by strain BCL-1. The optimum conditions for degradation were a pH of 8 and $30^{\circ}C$. The simulation of imidacloprid bioremediation by strain BCL-1 in soil demonstrated that the best performance in situ (tea soil) resulted in the degradation of 92.44% of the imidacloprid (100 mg/g) within 20 days, which was better than those observed in the ex situ simulations that were 64.66% (cabbage soil), 41.15% (potato soil), and 54.15% (tomato soil).

• Journal of Wetlands Research
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• v.19 no.4
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• pp.443-450
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• 2017

The objective of this study was to isolate algae growth inhibiting microorganism to biologically control Microcystis aeruginosa, which is a harmful cyanobacterium. Various bacterial strains were isolated in this study, and four bacterial strains of M1~M4 exhibited remarkable growth inhibiting activity against M. aeruginosa. Based on the 16S rRNA analysis, the isolated M1~M4 strains were identified, and isolated four strains were rod-type and gram-negative. In particular, as well as respective single strain, co-culture of the isolated M1~M4 strains showed obvious algicidal activity against M. aeruginosa. When mixed four strains were inoculated, about 50% of the chlorophyll a was reduced after two days, about 70% after four days, and about 80% after seven days. From these results mentioned above, the four bacterial strains may contribute to the control of harmful M. aeruginosa.