• The Plant Pathology Journal
• /
• 제17권3호
• /
• pp.174-179
• /
• 2001

The plant growth-promoting Pseudomonas strains, WR8-3 (Pseudomonas fluorescens), WR9-11 (Pseudomonas sp.) and WR9-16 (P.putida), which induced resistance systematically in watermelon to gummy stem rot were investigated on their induced systemic resistance(ISR)-related characteristics. The pyoverdine production was repressed in the standard succinate medium by increasing the concentration of $\textrm{FeCL}_3$. But the iron-binding ability on chrome azurol S agar media (CAS) was observed only in the strains, WR8-3 and WR9-16. When the two strains were mutated, the resulting iron-binding siderophore-negative mutants, WR8-3m and WR 9-16m, failed to promote the growth of watermelon and to induce resistance. The strains, WR8-3 and WR 9-16, slightly inhibited the growth of Didymella bryoniae at a low concentration of $\textrm{FeCL}_3$ on Kong's medium B, but not to exert control dffect. The strain WR9-11 showed antagonism in the concentration of $\textrm{FeCL}_3$ from 0 to $1,000\mu\textrm{M}$. When the crude lipoplysaccharide of each strain was treated in the rhizosphere of watermelon, mean lesion area was similar to that of the untreated control. The strains, WR9-11 and WR9-16 produced some level of hydrogen cyanide (HCN). Salicylic acid production was not detected in all of the strains.

• Journal of Microbiology
• /
• 제44권2호
• /
• pp.185-191
• /
• 2006

The photosynthetic bacterium, Rhodospirillum rubrum S1, when grown under anaerobic conditions, generated three different types of catalases. In this study, we purified and characterized the highest molecular weight catalase from the three catalases. The total specific catalase activity of the crude cell extracts was 88 U/mg. After the completion of the final purification step, the specific activity of the purified catalase was 1,256 U/mg. The purified catalase evidenced an estimated molecular mass of 318 kDa, consisting of four identical subunits, each of 79 kDa. The purified enzyme exhibited an apparent Km value of 30.4 mM and a Vmax of 2,564 U against hydrogen peroxide. The enzyme also exhibited a broad optimal pH $(5.0{\sim}9.0)$, and remained stable over a broad temperature range $(20^{\circ}C{\sim}60^{\circ}C)$. It maintained 90% activity against organic solvents (ethanol/chloroform) known hydroperoxidase inhibitors, and exhibited no detectable peroxidase activity. The catalase activity of the purified enzyme was reduced to 19 % of full activity as the result of the administration of 10 mM 3-amino-1,2,4-triazole, a heme-containing catalase inhibitor. Sodium cyanide, sodium azide, and hydroxylamine, all of which are known heme protein inhibitors, inhibited catalase activity by 50 % at concentrations of $11.5{\mu}M,\;0.52{\mu}M,\;and\;0.11{\mu}M$, respectively. In accordance with these findings, the enzyme was identified as a type of monofunctional catalase.

• 한국산업보건학회지
• /
• 제32권1호
• /
• pp.78-88
• /
• 2022

Objectives: To develop the smart sensor to protect worker's health from chemical exposure by adopting ICT (Information and Communications Technology) technologies. Methods: To develope real-time chemical exposure monitoring system, IoT (Internet of Things) sensor technology and regulations were reviewed. We developed and produced smart sensor. A smart sensor is a system consisting of a sensor unit, a communication unit, and a platform. To verify the performance of smart sensors, each sensor has been certified by the Korea Laboratory Accreditation Scheme (KOLAS). Results: Chemicals (TVOC; Total Volatile Organic Compounds, Cl₂: Chlorine, HF: Hydrogen fluoride and HCN: Hydrogen cyanide) were selected according to a priority logic (KOSHA Alert, acute poisoning statistics, literature review). Notifications were set according to OEL (occupational exposure limit). Sensors were selected based on OEL and the capabilities of the sensors. Communication is designed to use LTE (Long Term Evolution) and Wi-Fi at the same time for convenience. Electronic platform were applied to build this monitoring system. Conclusions: Real-time monitoring system for OEL of hazardous chemicals in workplace was developed. Smart sensor can detect chemicals to complement monitoring of traditional workplace environmental monitoring such as short term and peak exposure. Further research is needed to expand the scope of application, improve reliability, and systematically application.

• Asian-Australasian Journal of Animal Sciences
• /
• 제22권10호
• /
• pp.1366-1376
• /
• 2009

Effect of sulfur (S) on utilization efficiency of fresh cassava foliage and cassava hay in dairy cows was evaluated using thirty-two $1^{st}-2^{nd}$ lactation Holstein-Friesian crossbred dairy cows. The experimental treatment was a 2${\times}$2 factorial arrangement in a randomized complete block design (RCBD) using two roughages (rice straw+fresh cassava foliage (FCF) and rice straw+cassava hay (CH)) and two elemental sulfur (S) levels (0.15 and 0.4% S of dry matter (DM)), respectively. Four dietary treatments (FCF+0.15, FCF+0.4, CH+0.15 and CH+0.4) were offered ad libitum in the form of a total mixed ration (TMR) with concentrate to roughage (chopped rice straw+chopped cassava foliage) ratio at 60:40. Fresh cassava foliage or cassava hay resulted in similar dry mater intake, rumen ecology parameters, total tract digestibility, blood chemistry, milk production and composition. However, HCN intake, blood and milk thiocyanate concentration were significantly higher (p<0.01) in cows fed fresh cassava foliage with no sign of potential toxicity. Dry matter intake, body weight changes, molar percentage of propionate in rumen, neutral detergent fiber (NDF) digestibility and nitrogen (N) retention of cows tended to be increased while DM digestibility (65.6, 72.7, 68.6 and 72.1% of total DM intake for the respective treatments), rumen bacteria population (1.4, 1.7, 1.6 and $1.7{\times}10^{11}$ cell/ml for respective treatments), fungal zoospore population (0.4, 0.6, 0.4 and $0.5{\times}10^{6}$ cell/ml for respective treatments), urinary allantoin (25.3, 28.0, 26.3 and 27.6 g/d for respective treatments), microbial N yield (136.0, 154.6, 142.8 and 151.3 g N/d for respective treatments) and milk protein content (3.4, 3.5, 3.2 and 3.5% for respective treatments) were significantly (p<0.05) higher in cows fed on supplemented sulfur at 0.4% of DM in comparison with 0.15% S-supplemented diets. Based on these results, it is concluded that cassava foliage could be used as a portion of roughage for dairy cows and supplementation of S would be nutritionally beneficial.

• Toxicological Research
• /
• 제29권2호
• /
• pp.91-98
• /
• 2013

Armeniacae semen (AS) has been considered a toxic herb in the Korean medicine as it contains hydrogen cyanide and amygdalin, especially in its endocarp. Therefore, prebrewed AS that is devoid of endocarp has been traditionally used. In the present study, amygdalin content of the prebrewed AS was significantly lower ($2.73{\pm}0.32{\mu}g/ml$; p<0.01) than the content in the extract that contained the endocarps ($28.50{\pm}6.71{\mu}g/ml$); amygdalin content corresponded to 10% of the extract in the present study. Because of single oral dose toxicity of prebrewed AS according to the recommendation of Korea Food and Drug Administration Guidelines (2009-116, 2009), which was based on single oral dose toxicity study of prebrewed AS, mortality due to toxic principles was significantly reduced. In this study, 2,000 mg/kg of prebrewed AS led to death of 1 female rat and 1 male rat at the end of 2 hr of administration. Based on these results, the 50% lethal dose in both male and female rats was determined to be 9279.5 mg/kg. Seizure, loss of locomotion, and increases in respiration and heart rate were observed as prebrewed AS treatment-related toxicological signs; these signs were restrictedly manifested in the prebrewed AS (2,000 mg/kg)-treated rats. In addition, no changes were observed in body weight, organ weight, gross features, and histopathological parameters with 2,000 mg/kg of AS in both male and female rats. These findings serve as direct evidence that amygdalin in AS is the toxic principle, which can be reduced by the traditional prebrewing method involving the exclusion of endocarp.

• 농약과학회지
• /
• 제18권4호
• /
• pp.422-428
• /
• 2014

딸기 근권에서 분리한 내생균 중 고추역병균 방제 및 고추생육촉진 효과가 우수한 균주를 선발하였다. Pseudomonas fluorescen EP103으로 명명된 내생균주는 다른 내생균주와 비교하여 식물의 뿌리 길이와 생체 중이 크게 증가하였다. 고추역병에 대한 온실검정에서 EP103처리는 방제가 78.7%을 나타냈으며 항균력 실험결과 고추역병균을 직접 억제하지는 않았다. EP103이 처리된 고추에서는 PR1, PR10등의 병저항성 유전자가 발현되었으며 EP103의 PCR분석 결과 피올테오린, 파이로니트린, 하이드로젠 싸이아나이드, 오르화미드 등의 유용유전자를 함유하고 있음이 밝혀졌다. 따라서 본 균주는 고추역병의 생물 방제용으로 활용할 가치가 있는 것으로 판단된다.

• 한국균학회지
• /
• 제44권1호
• /
• pp.36-47
• /
• 2016

본 연구는 식물 근권에서 분리한 유용미생물 PA1, PA2, PA4, PA5, PA12 의 식물 생장 촉진능력과 식물 병원성 진균인 Colletotrichum acutatum, C. coccodes, C. gloeosporioides, C. dematium, Botrytis cinerea, Rhizoctonia solani, Sclerotinia minor 그리고 Fusarium sp.에 대한 생장억제능력을 평가하는데 그 목적이 있다. In vitro 실험에서 유용미생물의 식물 병원성 진균의 생장억제 능력을 확인하기 위해 세균배지인 TSA 배지와 곰팡이 배지인 PDA배지, 그리고 TSA와 PDA배지를 각각 50%씩 혼합한 배지(v/v, 1:1)에서 대치배양을 실시하였다. 그 결과 PDA배지에서는 PA2가 C. coccodes에 대해 65.5%로 가장 높은 억제능력을 보였으며, TSA배지에서는 PA2가 S. minor에 대해 96.5%로 가장 높은 억제력을 보였다. 또한 PDA와 TSA를 혼합한 배지에서는 PA2가 C. acutatum에 대해 58.5%로 가장 높은 억제능력을 보였다. 분리한 5균주 모두에서 식물병원성 진균에 대하여 생물적 방제 효과가 있음을 확인하였다. 또한 식물생장 촉진능력을 유발하는 원인물질을 탐색하기 위해 siderophore, protease, chitinase, hydrogen cyanide (HCN) 생성 유무를 확인하였고, phosphate solubilizing 실험을 실시하였다. 본 연구에서 사용된 유용미생물 5균주를 16s rDNA sequencing 결과 PA1, PA2는 Bacillus subtilis, PA4, PA5, PA12 각각 Bacillus altitudinis, Paenibacillus polymyxa, Bacillus amyloliquefaciens로 동정되었다.

• 미생물학회지
• /
• 제48권1호
• /
• pp.16-21
• /
• 2012

여러 식물의 근권에서 세균 균주들을 분리하여 이들의 항진균성 물질 생성능을 조사하였다. 분리균주 중 Fusarium oxysproum을 포함한 5가지 주요 식물병원성 진균에 대한 생장저해가 우수한 7개 균주를 16S rRNA 유전자 염기서열로 동정하였다. 이들 중 Paenibacillus peoriae RhAn32, Pseudomonas otitidis TK1과 Bacillus cereus TK2가 가장 넓은 생장 저해범위를 나타내었으며 항진균성 물질 중 siderophore 생성능은 P. otitidis TK1이 3.21 mM/ml로 가장 높았고 HCN은 Pseudomonas koreensis Rh2와 Rh7 균주만이 생성하였으며 Brevibacterium frigoritolerans EnA9와 P. peoriae RhAn32는 각각 1558.9와 $1436.7{\mu}M$ glucose/min/mg protein의 높은 chitinase 활성을 나타내었다. P. otitidis TK1과 P. peoriae RhAn32의 항진균능을 진균과의 공동배양을 통해 정량분석한 결과 세 종류의 Fusarium oxysproum의 생장을 유의성 있게 저해하였다. P. otitidis TK1은 식물생장을 촉진하는 호르몬인 auxin의 생성능도 가장 높았는데 이 균주를 4주 자란 토마토 유묘에 F. oxysporum f. sp. lycopersici와 동시에 접종하여 8주간 재배하였을 때 줄기와 뿌리 길이 및 습윤 중량이 비접종 대조군에 비해 각각 45.7, 64.9와 118%로 유의성 있게 증가하였다. 따라서 이 균주들은 유기합성농약을 대체하면서 식물생장을 촉진하는 미생물제로서의 적용이 가능할 것으로 기대된다.

• 한국화재소방학회논문지
• /
• 제31권6호
• /
• pp.23-32
• /
• 2017

폼블럭은 셀프 인테리어 용품으로 새롭게 유행하고 있는 건축마감재로 폴리에틸렌을 주성분으로 하여 제조되고 있어 화재에 취약할 것으로 판단된다. 시중에 판매되고 있는 폼블럭 2종(일반, 난연)을 KS F ISO 5660-1(연소성능시험)의 기준에 따라 화재시 발생되는 연소특성을 파악하였다. 또한 적외선분광계(FTIR)를 이용하여 시편의 연소로 발생하는 가스중 대표적 독성가스를 측정한 후 기존의 독성모델에 적용하였다. 콘칼로리미터 시험 결과 2종의 시편 모두 복사열 차단장치를 제거하자마자 인화 및 불꽃연소가 시작되어, 화재시 화염의 급속한 전파 요인이 될 수 있음을 확인하였으며, 적외선분광계를 통한 연소가스 분석 결과, 일반적인 연소가스인 이산화탄소와 일산화탄소뿐만 아니라 인체에 심각한 위해를 주는 아크롤레인, 암모니아 및 시안화수소 등이 다량 검출되었다. 본 연구를 통해 폼블럭 제품은 착화성과 발열량이 높으며 유해가스가 다량 방출될 수 있음을 실험을 통해 확인하였다. 따라서 폼불럭 사용에 따른 재료의 연소특성, 즉 착화성 저감, 최대 열방출률 제한 및 주요 유해가스의 농도를 제한하는 기준마련도 시급히 요구된다.

• 한국표면공학회지
• /
• 제13권3호
• /
• pp.146-154
• /
• 1980

The effects of various electrodeposition conditions (deposition temperature and cathode current density) on preferred orientation and microhardness of electrodeposited Ni-Sn and Sn-Zn alloys were studied. At deposition temperatures from 25$^{\circ}$ to 95$^{\circ}C$ and constant cathode current density of 270 and 530 A/$m^2$ Ni-Sn and Sn-Zn were codeposited in chloride-fluoride acid and stannate-cyanide alkaline electrolyte bath respectively. Ni-Sn alloy deposited at temperatures from 25$^{\circ}$ to 35$^{\circ}C$ was composed of single phase of $Ni_3Sn_4$ with 73 wt.% Sn and the one deposited at temperatures from 45$^{\circ}$ to 95$^{\circ}C$ was made of multiphase mixture of NiSn, $Ni_3Sn_2$ and $Ni_3Sn_4$ with nearly equiatomic composition (65.5 wt.% Sn). The random orientation of thermody-namically metastable NiSn phase (hexagonal structure) predominated at deposition temperature range 25$^{\circ}$-45$^{\circ}C$, and the strong (110) preferred orientation was found at 65$^{\circ}$-85$^{\circ}C$ and then disappeared again at 95$^{\circ}C$. The microhardness of Ni-Sn deposits increased with deposition temperature up to 85$^{\circ}C$, and then decreased at constant cathode current density. The preferred orientation and the maximum microhardness were discussed in terms of lattice contractile stress which result from desorption of hydrogen atom absorbed in deposit lattice. The Sn content of Sn-Zn alloy deposits increased with deposition temperature up to 75$^{\circ}C$, and then decreased at constant cathode current density of 530 A/$m^2$. It also decreased with cathode current density up to 530 A/$m^2$, and then increased at constant deposition temperature of 25$^{\circ}C$. Sn-Zn alloy deposits were composed of two-phase mixture of ${beta}$-Sn and Zn. The preferred orientations of ${beta}$-Sn (tetragonal structure) changed with deposition temperature. The microhardness of Sn-Zn deposits decreased with deposition temperature. It also increased with cathode density up to 530 A/$m^2$, and then decreased at constant deposition temperature of 25$^{\circ}C$. The microhardness of Sn-Zn deposits was observed to be determinded more by the Sn content than by the preferred orientation.