The JK-1 isolate which was the best producer of indole-3-acetic acid and carotenoid among the 388 strains isolated from 28 wetlands in Jeju, was identified to be Rhodopseudomonas palustirs belongs to a typical group of non sulfur purple bacteria based on 16S sRNA sequencing. This study investigated the effect of different cultural conditions of pH, temperature, agitation, light and aeration on growth, IAA and carotenoid production of photosynthetic bacterium JK-1 for optimization of IAA and carotenoid production. It was found that growth, IAA, carotenoid, and bacteriochlorophyll production with light (3,000~3,500 Lux) and agitation (100 rpm) showed better results than those with dark/static or dark/ agitation (100 rpm) in anaerobic conditions. The optimal pH, temperature and agitation speed for cell growth were 7, 30℃, 150 rpm, for IAA production were 9, 30℃, 150rpm and for carotenoid production were 6, 25℃, 50 rpm, cultured for 72 h under anaerobic light, respectively. The growth and IAA production were high in aerobic culture compared with anaerocic culture, whereas carotenoid and bacteriochlorophyll content were decreased extremely in aerobic condition (0.5~1 vvm). Subsequently, the optimal culture conditions for JK-1 were selected with pH 7, 30℃ and 100 rpm under anaerobic light and the effect on plant growth was tested by pot assay. Inoculation of JK-1 with 3% (v/v) level caused increase in shoot and root dry weigh that varied from 20%~58% to 40%~28% in young radish in camparison to uninoculated treatment at 50 days of growth. The study suggests that the JK-1 isolate may serve as efficient biofertilizer inoculants to promote plant growth.

피부의 생태계는 미생물에게 다양한 형태의 서식처를 제공하며, 광범위한 미생물들이 살고 있다. 숙주인 사람은 이들과 공생관계를 이루고 있으며, 이들은 숙주에 많은 긍정적인 영향을 미친다. 피부에 분포하는 미생물 들의 다양한 대사물질은 피부세포에 영향을 미치고, 피부장벽 기능, 노화방지 및 항염증에 광범위한 효능을 나타 내는 것으로 알려져 있다. 본 연구에서는 사람의 피부에서 신규한 Sporichthyaceae bacterium strain K-07을 분리하였고, 해당 미생물의 16S rRNA 분석결과 Sporichthya속의 미생물과 상동성이 93.4%인 것으로 신규 속(genus)으로 확인되었다. 그리고 신규로 분리된 K-07 배양액을 처리하였을 때, HaCaT cell에 어떤 변화가 나타나는지에 대한 분석을 실시하였다. 분리된 신규 미생물 strain K-07의 16S rRNA sequence 분석결과 상 동성이 93.4% 이하로 확인되었고, 보고되지 않은 새로운 종으로 확인되었다. Filaggrin, cluadin1, claudin4, αSMase, 및 CerS3 / HAS3 및 aquaporin3 / IL-6 및 TNF-α / TSLP 및 TARC를 대상으로 strain K-07 배양액을 처리하여 변화를 관찰하였다. 그 결과 filaggrin, cluadin1, claudin4, αSMase, 및 CerS3 / HAS3 및 aquaporin3에서는 음성 대조군 대비 우수한 증가 효과가 나타남을 확인하였다. 그리고 IL-6 및 TNF-α / TSLP 및 TARC에 대해서도 우수한 억제능을 나타내는 것을 확인하였다. 결론적으로 신규 미생물 strain K-07 배양액은 피부 장벽활성 증진에 매우 효과적인 작용을 하며, 염증 억제에 우수한 효능을 나타내는 것으로 확인되 므로 피부에 효과적인 소재로 사용될 수 있을 것이다.

This experiment was conducted to investigate the endophytic bacterium Herbaspirillum spp effect on seed germination and sprout growth of tartary buckwheat. Inoculant concentration (%v/v) and seed soaking time were applied 10, 20 and 40% and 0, 4, 8, 12 hour, respectively. The experiment was carried out in a growth chamber maintained temperature at 20, 25 and 30ºC without light for 7 days. Results showed that, 10 to 20% (v/v) inoculant concentration by 4 to 8 h seed soaking time at 20°C temperature increased seed vigor rate and total seed germination rate 80-95% and 90-100%, respectively. On the other and, seed inoculation with Herbaspirillum spp. increased hypocotyl length (13-15 ㎝), root length (8-11 ㎝), total fresh weight (135-296 g) and total dry weight (7-10 g), compared to control. It is indicated that sprouts growth and yield depends on inoculation concentrations, seed soaking time and temperature. Therefore, it would be suggested that seed inoculation with Herbaspirillum spp. at concentration of 10 to 20% (v/v), soaking time 4 to 8 h and temperature 20°C promote seed germinations and sprout growth rate of tartary buckwheat.

Drought stress is a major agricultural limitation to crop productivity worldwide, especially by which leafy vegetables, plant leaves eaten as vegetable, could be more lethal. The study was carried out to know the effect of drought tolerance plant growth promoting bacteria (PGPB) on water stress of kale seedlings. A total of 146 morphologically distinct bacterial colonies were isolated from bulk soil and rhizosphere soil of leafy vegetables and screened for plant growth promoting microbioassay in greenhouse. Out of them the isolate SB19 significantly promoted the growth of kale seedlings in increasement of about 42% of plant height (14.1 ㎝), 148% of leaf area (19.0 ㎠) and 138% of shoot fresh weight (1662.5 ㎎) attained by the bacterially treated plants compared to distilled water treated control (9.9 ㎝, 7.7 ㎠, 698.8 ㎎). Shoot water content of SB19 treated kale seedlings (1393.8 ㎎) was also increased about 152% compared with control (552.5 ㎎). The SB19 isolated from bulk soil of kale plant in Iksan, Korea, was identified as species of Bacillus based on 16S rRNA gene sequencing analysis. We evaluated the effect of drought tolerance by the Bacillus sp. SB19 on kale seedlings at 7th and 14th days following the onset of the water stress and watering was only at 7th day in the middle of test. In the survey of 7th and 14th day, there were mitigation effect of drought stress in kale seedlings treated with 106 and 107 cell mL-1 of SB19 compared to distilled water treated control. Especially, there were more effective mitigation of drought damage in kale seedlings treated with 107 cell mL-1 than 106 cell mL-1. Further, although drought injury of bacterially treated kale seedlings were not improved at 14th day compared with 7th day, drought injury of 107 cell mL-1 of SB19 treated kale seedlings were not happen rapidly but developed over a longer period of time than 106 cell mL-1 of SB19 or control. The diffidence of results might be caused by the concentration of bacterial suspension. This study suggests that beneficial plant-microbe interaction could be a important role of enhancement of water availability and also provide a good method for improving quality of leafy vegetables under water stress conditions.

피부는 외부 유해물질로부터 내부기관을 보호하는 장벽기능을 하는 대표적인 기관으로 자외선 (ultraviolet radiation, UV), 중금속, 각종 산화 물질들과 같은 외부의 위협에 항상 노출되어 있어 손상을 받 기 쉽다. 특히 자외선 B (UVB)는 진피의 상부까지 도달하여 화상이나 홍반과 같은 염증반응을 일으키며 멜라 닌 생성을 촉진시켜 색소 침착을 유발한다. 지나친 자외선 B의 피부세포로의 유입은 각질세포 및 진피 섬유아 세포의 DNA손상을 야기하고, 세포외기질의 합성을 방해하여 피부탄력감소, 주름생성, 진피 결합조직의 손상 과 함께 피부장벽을 붕괴시켜 노화를 일으키며, 장기간 노출 시 심각한 피부 병변으로 이어져 피부세포 사멸 및 종양의 발생으로까지 이어진다. Haloarcula vallismortis는 사해로부터 분리 동정한 미생물로 호염성 고생 물의 생장적 특징은 아직 자세히 연구된 바는 없다. 대게 10% 이상의 염도에서 자라는데 실제 생장염도는 평균 20 ∼ 25% 염도에서 자란다. 염도가 높은 호수나 염전에서 주로 발견되기 때문에 강한 햇빛에 대한 방 어기작이 존재한다. 그중 하나로 다른 ATP를 생성하기 위한 bacteriorhodopsin외에 halorhodopsin이라는 색소를 이용, 광자(photon)를 흡수하고 염화이온 채널을 개방시켜 생기는 전위차를 이용해 추가로 에너지를 생산한다. 또 carotenoid 색소로 인해 농도가 높을시 분홍색 또는 빨간색을 띄는 특징이 있는데 이것이 강한 자외선에 대한 방어기작을 할 것이라고 여겨진다. 본 연구는 호염성 고세균이 자외선을 에너지 소스로 이용하 는 특성을 이용하여 자외선으로부터 피부를 방어하는 방법을 개발하고자 이들의 피부각질세포에서 자외선에 의한 항염 효과 및 DNA 손상 방어 효과를 확인하였다. 그리고 이들을 천연 자외선 차단제의 소재로서 사용 할 수 있음을 확인하였다.

방사성 폐기물을 지하에 장기 보관하는 금속 용기에 관한 생지화학적 부식 특성을 알아보기 위해 주철과 구리로 된 금속재료를 환원조건 하에서 디설프리칸스 황산염환원미생물과 3개월간 반응시켰다. 금속재료의 화학적/광물학적 변화를 알아보기 위해 주기적으로 용존 금속이온들의 농도를 측정하였으며, 실험이 종료된 이후 금속 시편 및 표면 이차생성물들을 전자현미경을 이용하여 분석하였다. 디설프리칸스가 없는 조건에서는 금속재료의 부식이 매우 미약하였으나, 미생물이 있는 경우에는 부식이 상대적으로 컸다. 관찰된 생지화학적 부식 산물은 주로 맥키나와이트와 황화구리 같은 검은색의 금속황화물이었으며, 표면에서 쉽게 분리되거나 콜로이드화되어 부유하였다. 특히, 구리 시편의 경우 용액 상에 용존 철이 존재할 때 세균에 의한 구리 부식의 가속화가 관찰되었는데, 이는 구리 표면에 다른 종의 황화철이 성장하면서 구리 간의 결속력을 약화시켰기 때문인 것으로 보인다.

철환원 박테리아인 미시가넨시스를 이용하여 용존 셀레늄을 제거할 때, 물 속의 다른 금속성분들인 철, 황산염, 그리 구리가 미칠 수 있 영향을 살펴보았다. 미시가넨시스 박테리아는 산화수가 4가인 산화 셀레나이트(2 mM)를 셀레나이드로 환원시키고 물속의 셀레늄 농도를 점차 감소시켰다. 환원된 셀레나이드는 용존 2가 철과 결합하여 나노입자 크기의 철-셀레나이드로 침전되었다. 용존 황산염과 구리는 미생물의 셀레나이트 환원작용에 부정적인 영향을 끼쳤는데, 특히 구리 성분은 미생물에 대해 독성으로 작용하여 셀레나이트 제거가 원활히 이뤄지지 못하게 하였다. 이러한 결과로부터 알 수 있는 것은 셀레늄으로 오염된 현장을 미생물로 정화할 때 황산염 혹은 구리의 농도 분포와 양을 충분히 고려해야 한다는 사실이다. 궁극적으로 미생물에 의한 철-셀레나이드 광물형성작용은 지하수를 따라 원거리로 이동할 수 있는 셀레늄의 확산을 억제하는 중요한 수단이라고 볼 수 있다.

Three biphenyl-degrading microorganisms were isolated from polluted soil samples in Sasang-gu, Busan. Among them, isolate DS-94 showing the strong degrading activity was selected. The morphological, physiological, and biochemical characteristics of DS-94 were investigated by API 20NE and other tests. This bacterium was identified as the genus Pseudomonas by 16S rDNA sequencing and designated as Pseudomonas sp. DS-94. The optimum temperature and pH for the growth of Pseudomonas sp. DS-94 were 25℃ and pH 7.0, respectively. This isolate could utilize biphenyl as sole source of carbon and energy. Biphenyl-degrading efficiency of this isolate was measured by HPLC analysis. As a result of biological biphenyl-degradation at high biphenyl concentration (500 mg/L), biphenyl-removal efficiency by this isolate was 73.5% for 7 days.

우리나라 전통발효식품의 하나인 청국장으로부터 고 비활성 세포외 protease 생산능이 우수한 균주를 분리하고 그 특성을 조사하였다. 분리된 균주 중 D14 균주 배양 상징액의 protease 활성이 15.2 U/mL로서 가장 강하였으며 비활성 또한 40.0 U/mg protein으로서 가장 강하게 나타났다. 이 균주의 특성을 조사한 후 Berge's Manual of Systematic Bacteriology에 준하여 Bacillus subti

The aerobic photosynthetic bacterium, which produces bacterial carotenoids was isolated and identified from coastal marine environments. This bacterium was identified by 16S rDNA sequencing and designated as Erythrobacter longus SY-46. E. longus SY-46 was Gram negative and rod shape, and the optimal culture conditions were 25℃, pH 7.0, and 3.0% NaCl concentration, respectively. The carbon and nitrogen sources required for the optimal growth were lactose and tryptone, respectively. Fatty acid compositions of E. longus SY-46 were C18:1(78.32%), ν-linolenic acid(C18:3n9.12.15c: 3.83%), margaric acid(C17:0: 3.38%), palmitic acid(C16:0: 3.07%), and docosahexaenoic acid(C22:6n3: 2.21%). In addition, E. longus SY-46 showed the characteristic absorption peaks of bacterial carotenoids(in the region of 450 to 480 nm) and bacteriochlorophyll(770 to 772 nm). Major carotenoids of E. longus SY-46 were polyhydroxylated xanthophylls such as fucoxanthin and zeaxanthin.

The aim of this study was to isolate chicken feather-degrading bacteria with high keratinolytic activity and to investigate cultural conditions affecting keratinolytic enzyme production by a selected isolate. A chicken feather-degrading bacterial strain CH3 was isolated from poultry wastes. Isolate CH3 degraded whole chicken feather completely within 3 days. On the basis of phenotypical and 16S rDNA studies, isolate CH3 was identified as Bacillus thuringiensis CH3. This strain is the first B. thuringiensis described as a feather degrader. The bacterium grew with an optimum at pH 8.0 and 37℃, where maximum keratinolytic activity was also observed. The composition of optimal medium for keratinolytic enzyme production was feather 0.1%, sucrose 0.7%, casein 0.3%, K2HPO4 0.03%, KH2PO4 0.04%, MgCl2 0.01% and NaCl 0.05%, respectively. The keratinolytic enzyme had a pH and temperature optima 9.0 and 45℃, respectively. The keratinolytic activity was inhibited ethylenediaminetetraacetic acid, phenylmethylsulfonyl fluoride, and metal ions like Hg2+, Cu2+ and Zn2+. The enzyme activated by Fe2+, dithiothreitol and 2-mercaptoethanol.

A species of facultative photo-organotrophic, purple, non-sulfur bacterium was isolated from the 47 point at west and south coast of Korea in September 2001. Separated 13 samples of changes with red color under 28～32 ℃, 3000 lux, anaerobe conditions for 7 days cultivated in basal medium. For pure isolation from 13 samples, we used agar-shake tube method (0.4 % agar) and separated 5 strains through 13-repetition test. EGH-24 and EGH-30 was identified as the same strain through the RAPD(Random Amplified Polymorphic DNA)-PCR of strain EGH-9, EGH-13, EGH-23, EGH-24, EGH-30. Four isolates cultivated in synthesis wastewater for wastewater biodegradation test. EGH-24 was selected with efficient wastwater treating strain. Based on the results obtained from morphology, nutrient requirements, major bacteriochlorophyll content, 16S-rDNA phylogenetic analysis, EGH-24 strain may be identified as a new strain of the genus Rhodobacter and named Rhodobacter sp. EGH-24.

Pseudomonas sp. EL-04J was previously isolated from phenol-acclimated activated sludge. This bacterium was capable of degrading phenol and cometabolizing trichloroethylene (TCE). After precultivation in the mineral salts medium containing phenol as a sole carbon source, Pseudomonas EL-04J degraded 90% of TCE 25μM within 20 hours. Thus, phenol-induced Pseudomonas sp. EL-04J cells can degrade TCE. Following a transient lag period, Pseudomonas sp. EL-04J cells degraded TCE at concentrations of at least 250μM with no apparent retardation in rate, but the transformation capacity of such cells was limited and depended on the cell concentration. The degradation rate of TCE followed the Michaelis-Menten kinetic model. The maximum degradation rate (Vmax) and saturation constant (Km) were 7nmo ℓ/min·㎎ cell protein and 11μM, respectively. Cometabolism of TCE by phenol fed experiment was evaluated in 50·mℓ serum, vial that contained 10 ㎖ of meneral sals medium supplemented with 10μM TCE. TCE degradation was inhibited in the initial period of 1 mM phenol addition, but after that time Pseudomonas sp. EL-04J cells degraded TCE and showed cell growth.

Several microorganisms which degrade phenol and trichloroethylene (TCE) were isolated from the activated sludge of a wastewater treatment plant. Among them, one isolate EL-04J showed the highest degradability and was identified as a Pseudomonas species according to morphological, cultural and biochemical properties. The phenol-induced cells of Pseudomonas EL-04J, which were preincubated in the mineral salts medium containing phenol as a sole carbon source, degraded 90% of 25μM TCE within 20 h. This strain could also utilize some of methylated phenol derivatives (o-cresol, m-cresol and p-cresol) as the sole source of carbon and energy. Cresol-induced cells of Pseudomonas EL-04J also cometabolized TCE.

Microorganisms producing bioemulsifier were isolated from the sea water in Pusan coastal area. The isolated strain which had the highest emulsification activity and stability was identified as the genus Acinetobacter from the results of morphological, cultural and biochemical tests and named Acinetobacter sp. EL-C6 for convenience. The compositions of optimum medium for emulsification of crude oil by Actnetobacter sp. EL-C6 were crude oil 2.0%, NH_4NO_3 0.2%, K_2HPO_4 0.01%, MgSO_4·7H_2O 1.0%, CaCl_2·2H_2O 0.1% and NaCl 3.0% at initial pH 7.5 and 30℃, respectively. The cultivation for emulsification of crude oil was carried out in 500㎖ shaking flask containing 100㎖ of the optimum medium at 30℃. The highest emulsification was observed after 5 days. The utilization on the various hydrocarbon of the Acinetobacter sp. EL-C6 showed that utilization of n-alkane compounds were better than that of aromatic compounds. Among the petroleum compounds, crude oil was best utilized by the Actnetobacter sp. EL-C6.

The bacterial strains, which utilizes 2,4,4`-trichloro-2`-hydroxydiphenyl ether(TCHDPE) as a sole carbon source, were isolated by selective enrichment culture from soil samples of industrial waste deposits. The bacterium that showed the highest biodegradation activity was designated as EL-047R. The isolated strain EL-047R was identified as the genus Pseudomonas from the results of morphological, cultural, and biochemical tests. The optimum conditions of medium for the growth and the degradation of TCHDPE were TCHDPE 500 ppm, (NH_4)_2SO_4 0.1% as the nitrogen source, initial pH 7.0±0.1, and 37℃, respectively. In this conditions, the degradation rate of TCHDPE was about 97%. Pseudomonas sp. EL-047R was tested for resistance to several metal compounds and antibiotics. Pseudomonas sp. EL-047R was moderately grown to Cd(NO_3)_2, ZnCl_2, AgSO_4, CuSO_4 and HgCl_2. This strain was sensitive to rifampicin and kanamycin but resistant to ampicillin, penicillin, tetracyclin and chloramphenicol. Pseudomonas sp. EL-047R was grown structurally related compounds and potential metabolites of TCHDPE, and has the stability on TCHDPE biodegradation.