• Applied Biological Chemistry
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• v.36 no.6
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• pp.488-494
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• 1993

A photosynthetic bacterium strain P17 having high growth rate and assimilating ability of organic acids was isolated from several soil samples, which was identified as Rhodospirillum rubrum. Cultural conditions of the strain P17 were examined for the production of starter culture used in the treatment of organic waste water. The addition of organic acids mixture as carbon source containing 0.2% Na-acetate, 0.1% Na-propionate and 0.2% Na-lactate and 0.1% of yeast extract as growth factor stimulated the cell growth. The maximal cell production was obtained at $30^{\circ}C$, pH 7.0, 2,500 lux of illumination and $50{\sim}100\;rpm$ of agitation. Under the optimal conditions of batch and fed-batch culture systems in a Jar fermentor, 5.17 g/l and 7.93 g/l of cells were obtained after S days of cultivation, respectively. In continuous culture system, the cell productivity was 0.206 g/l/h at a dilution rate of 0.21 $h^{-1}$. When R. rubrum P17 was cultivated in a soybean curd waste water, initial COD level(3,240 mg/l) of the waste water was reduced to 250 mg/l after 4 days of cultivation.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.207-211
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• 2005

The metabolites released from cultures of rhizosphere bacteria can inhibit plant growth. Bacillus subtilis IJ-31 inhibited plant growth by the production of hydrocinnamic acid (HCA). The production of HCA by plant-growth inhibiting rhizobacterium B. subtilis IJ-31 was optimized. $90.5\;{\mu}g/ml$ of HCA was obtained under the condition of 1% rice bran as carbon source, 0.5% tryptone as nitrogen source, 0.1% $ZnCl_2$ as metal source at $37^{\circ}C$ for 60 h (pH 7.0). The optimal condition for the HCA production by B. subtilis IJ-31 in the jar fermenter was established using response surface methodology (RSM) of statistical analysis system(SAS) program. The production of HCA by B. subtilis IJ-31 in the jar fermenter culture reached $102.99\;{\mu}g/ml$ when 2.24% soil extracts was added and agitation speed was 290 rpm under the same condition. And the experimental value of HCA production is $102.5\;{\mu}g/ml$ in the same culture condition. The production of HCA by B. subtilis IJ-31 is higher as 12% than that from the flask culture.

• Applied Biological Chemistry
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• v.46 no.4
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• pp.285-290
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• 2003

This study was conducted to select the bacteriocin-producing microoreanism cultivated in the rice bran culture and to characterize the produced bacteriocin for the further purpose of economical and anti-bacterial rice bran protein film. Pseudomonas putida 21025 was cultivated from rice bran and identified as a producer of a bacteriocin which showed bactericidal activity against Pseudomonas aeruginosa 9027. Bacteriocin produced by Pseudomonas putida 21025 showed a broad spectrum of activity against spoilage and soil bacteria. The activity of the bacteriocin produced by Pseudomonas putida 21025 decreased after 1 hr of staying at the temperature of $50^{\circ}C$, and with the presence of some organic solvents, except hexane and ethanol. However, the bacteriocin activity was stable throughout the pH ranges of 6-9 for 2 hrs, at the temperature lower than $50^{\circ}C$, and with the presence of ethanol for 3 hrs. The bacteriocin was partially purified by 50% ammonium sulfate precipitation followed by subsequent dialysis. Direct detection of the partially purified bacteriocin on SDS-PAGE suggested that it had an apparent molecular mass of about 21.6 kDa.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.105-110
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• 2004

Microorganism (strain DF 218) producing thermostable pretense was isolated from Korean soil and compost. It was Gram-positive, rod-shaped, aerobic, and spore-forming with yellowish white colony color, Temperature range for growth at pH 6.5 was $30-65^{\circ}C$, with optimum growth at $60^{\circ}C$. pH range for growth at $60^{\circ}C$ was 5-7 with optimum of 6.5, which indicates strain DF 218 to be thermophilic. The 16S rDNA sequence of strain DF 218 had 95% sequence similarity with that of Bacillus flexus. Based on physiological properties and phylogenetic analysis, we proposed the isolated strain as Bacillus sp. DF 218. Pretense was produced aerobically at $60^{\circ}C$ for 32 hr in a medium (pH 6.5) containing 1% each trypton, glucose, and NaCl. Its molecular weight was estimated as 61 kDa, with optimum temperature and pH of $60^{\circ}C$ and 7.5, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.12
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• pp.1285-1291
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• 2005

In this study, we isolated bacteria from petroleum contaminated soil which were near to underground storage tanks(UST). Through the screen test, we selected high efficiency bacterium, KDi19, for biodegradation of diesel. KDi19 was identified as Pseudomonas sp. by 16S rDNA, fatty acid, and morphological physiological characteristics. KDi19 degraded 956.3 mg/L(95.6%) of 1,000 mg/L diesel for 48 hours(incubation condition : temperature; $30^{\circ}C$, cell concentration; 1.0 g/L, pH 7). At low temperature, $20^{\circ}C$, $15^{\circ}C$, $10^{\circ}C$, KDi19 respectively removed 63.9%, 18.5% and 17.0% of 1,000 mg/L diesel for 48 hours(cell concentration 1.0 g/L, pH 7). At low concentration of diesel, 50 mg/L and 100 mg/L, KDi19 degraded 97.9% and 96.2% of diesel for 24 hours(temperature; $30^{\circ}C$, cell concentration: 1.0 g/L, pH 7), respectively.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.1
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• pp.42-46
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• 2004

Deep Ocean Water (DOW) is formed within restricted area including polar sea (high latitude) by cooling of surface seawater and globally circulating in the state of isolation from surface seawater. Although it is not as obvious as estuaries mixing, brine ground water is mixture of recirculated seawater and ground water. Seawater having high osmotic pressure infiltrates into an aquifer which is connected to the sea. In order to clarify the characteristics of deep ocean water and brine ground water, we investigated their origins, chemical compositions, water qualities and resources stabilities. While concentrations of stable isotopes (/sup 18/O and ²H) in seawater is 0‰, those in brine ground water is on meteoric water line or shifted toward oxygen line. It means that origin of brine ground water is different than that of deep ocean water. The ions dissolved in seawater (Na, Ca, Mg, K) are present in constant proportions to each other and to the total salt content of seawater. However deviations in ion proportions have been observed in some brine ground water. Some causes of these exception to the rule of constant proportions are due to many chemical reactions between periphery soil and ground water. While DOW has a large quantity of functional trace metals and biological affinity relative to brine ground water, DOW has relatively small amount of harmful bacteria and artificial pollutants.

• Microbiology and Biotechnology Letters
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• v.30 no.3
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• pp.235-240
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• 2002

Streptomycetes is a group of Gram-positive soil bacteria that growas a branching vegetative mycelium leading to the formation of spores, and display a physiological differenti-ation related to the synthesis of many secondary metabolites including antibiotics. Their complex life cycle and multicellular differentiation require various levels of regulation and types of signal transduction systems including eukaryotic-type serine/threonine protein kinases and prokaryotic-type histidine/aspartic acid protein kinases. Akt kinase that was found in cells is a sorine/threonine kinase controlling signal pathway for multi-tude of important cellular events. The activation or inactivation of Akt kinase in the cell is one of the critical regulatory points to deliver cell proliferation, differentiation, survival or apoptosis signal. To find the regula-tory protein homologous to Akt in Streptomyces, the fluorescien-labeled synthetic peptide (FITC-TRRSR-TESIT) was designed from the consensus sequence of target proteins for Akt kinase. From the difference of the mobility between the nonphosphorylated and phosphorylated synthetic peptides on Agarose gel electro-phoresis, the Akt-phosphorylating activity was monitored. The cell-free extract prepared from Streptomyces griseus IFO 13350 and the Akt homologous protein was purified by ammonium sulfate fractionation and many steps of column chromatographies such as, DEAE-Sepharose, Mono Q, Resource Phenyl-Soporose and Gel permeation column chromatographies. As a result, the protein phosphorylating the fluorescien-labeled Akt substrate was identified and it's molecular weight was estimated as 39 kDa on SDS-PAGE.

• Microbiology and Biotechnology Letters
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• v.5 no.4
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• pp.177-184
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• 1977

Arylsulfatase catalyzes the release of SO$\sub$4//sup2/- from sulfate esters of simple phenols. Arylsolfatase occurs widely in animal tissues and in microorganisms including soil bacteria. Its widespread distribution suggests that it has a rather fundamental function and environmental meaning. It has been shown previously that arylsulfatase of Klebsiella was purified and characterized. A condition of arylsulfatase synthesis was tested with several strains of Serratia. Serratia marcescens could not utilize some sugars, such as xylose, rhamnose, glucosamine and arabinose hut glucose and mannitol as a sole carbon source. However, arylsulfatase synthesis was repressed by glucose but not by mannitol. The enzyme synthesis was repressed ob inorganic sulfate and methionine, and this repression was relieved by addition of tyramine. Arylsulfatase of S. marcescen was purified by fractionation with ammonium sulfate and followed by chromatographies on DEAE-Cellulose CM-Cellulose, and DEAE-Sephadex A-25. The molecular weight of arylsulfatase was determined to be 46,000 by SDS-Gel electrophoresis and 49,000 by Sephadex G-100 column chromatography. The enzyme showed some different properties with that of K. aerogenes. The activity was maximum at pH 6.8. The Km and Vmax values for p-nitrophenyl sulfate were 2.5${\times}$10$\^$－4/ M and 20 nmoles/min/mg protein, respectively. The enzyme showed high activities toward phenyl sulfate, ο-and p-nitro phenyl sulfates, and p-nitrocatechol sulfate. The inhibition of enzyme was strongly affected by hydroxylamine, inorganic fluoride, sulfide and phosphate, but by inorganic sulfate. Like Klebsiella arylsulfatase, tyramine, octopamine, and dopamine gave signifcant inhibitory effect.

• Microbiology and Biotechnology Letters
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• v.39 no.2
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• pp.104-110
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• 2011

Actinomycetes, Gram positive soil bacteria, are valuable microorganisms which produce useful secondary metabolites including antibiotics, antiparasitic substances, anti-cancer drugs, and immunosuppressants. Although a major family of actinomycetes, known as streptomycetes, has been intensively investigated at the molecular level for several decades, a potentially valuable and only recently isolated non-streptomycetes rare actinomycetes (NSRA) family has been poorly characterized due to lack of proper genetic manipulation systems. Here we report that a PCR-based genome screening strategy was performed with approximately 180 independently isolated actinomycetes strains to isolate potentially valuable NSRA strains. Thanks to this simple PCR-based genome screening strategy we were able to identify only seven NSRA strains, followed by 16S rRNA sequencing for confirmation. Through further bioassays, one potentially valuable NSRA strain (tentatively named Nocardiopsis species MMBL010) was identified which possessed both antifungal and antibacterial activities, along with the presence of polyketide synthase and non-ribosomal peptide synthase genes. Moreover, Nocardiopsis species MMBL010, which was intrinsically recalcitrant to genetic manipulation, was successfully transformed via E. coli-driven conjugation. These results suggest that PCR-based genome screening, followed by the establishment of an E. coli-driven conjugation system, is an efficient strategy to maximize potentially valuable compounds and their biosynthetic genes from NSRA strains isolated from various environments.

• Journal of Environmental Science International
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• v.23 no.6
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• pp.1095-1100
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• 2014

Keratin wastes are generated in excess of million tons per year worldwide and biodegradation of keratin by microorganisms possessing keratinase activity can be used as an alternative tool to prevent environmental pollution. For practical use of keratinase, its physicochemical properties should be investigated in detail. In this study, we investigated characteristics of keratinase produced by Xanthomonas sp. P5 which is isolated from rhizospheric soil of soybean. The level of keratinase produced by the strain P5 increased with time and reached its maximum (10.6 U/ml) at 3 days. The production of soluble protein had the same tendency as the production of keratinase. Optimal temperature and pH of keratinase were $40^{\circ}C-45^{\circ}C$ and pH 9, respectively. The enzyme showed broad temperature and pH stabilities. Thermostability profile showed that the enzyme retained 94.6%-100% of the original activity after 1 h treatment at $10^{\circ}C-40^{\circ}C$. After treatment for 1 h at pH 6-10, 89.2%-100% of the activity was remained. At pH 11, 71.6% of the original activity was retained after 1 h treatment. Although the strain P5 did not degrade human hair, it degraded duck feather and chicken feather. These results indicate that keratinase from Xanthomonas sp. P5 could be not only used to upgrade the nutritional value of feather hydrolysate but also useful in situ biodegradation of feather.