• Journal of Plant Biotechnology
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• 제49권4호
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• pp.356-361
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• 2022

본 연구에서는 Bacillus amyloliquefaciens ISP-5 균주의 최적배지조성을 확인하기 위해 5종의 탄소원(glucose, fructose, sucrose, maltose, corn starch)과 5종의 질소원(yeast extract, peptone, tryptone, soytone, soy bean flour)을 이용하여 각각의 생육을 측정하였다. 그 결과 glucose와 soy bean flour를 각각 최적 탄소원과 질소원으로 확립하였으며 최적 배지를 이용하였을 때 상업용 배지(TSB)에 비해 약 2500배의 생육을 확인할 수 있었다. B. amyloliquefaciens ISP-5 배양액을 상추에 엽면 살포하였을 때 상추의 엽폭과 엽장은 대조군에 비해 8.6%, 12.9%의 증가하였으며, 생체중과 건물중은 대조군에 비해 각각 24.2%, 23.9% 증가하였다. 이러한 결과들을 종합해보았을 때 B. amyloloiquefaciens ISP-5 균주를 이용한 미생물 제제는 상추용 식물생장촉진제로써 활용할 수 있을 것이라 기대된다.

• 농업생명과학연구
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• 제50권4호
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• pp.27-34
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• 2016

고추를 비롯한 채소작물에 심각한 피해를 야기하는 흰비단병의 생물학적 방제제를 개발하기 위하여 시설재배 토양에서 분리한 세균 중에서 흰비단병균인 Sclerotium rolfsii의 균사생장을 강하게 억제하는 균주를 선발하였다. 선발된 균주는 형태적, 생리적 분석과 16S rRNA 분석결과를 바탕으로 Bacillus amyloliquefaciens로 동정하였고 최종 선발균주를 Bacillus amyloliquefaciens KBC1009로 명명하였다. Bacillus amyloliquefaciens KBC1009의 배양특성을 조사한 결과 배양온도 30℃, pH 7의 조건에서 72시간동안 배양했을 때 배양 효율이 가장 우수하였으며, 배양에 적정한 영양원은 탄소원 glucose, 질소원 yeast extract를 사용했을 때 가장 높은 균수를 나타내었다. 포장에서 고추 흰비단병에 대한 Bacillus amyloliquefaciens KBC1009의 방제효과를 검정하기 위해 흰비단병원균을 토양에 접종하고 B. amyloliquefaciens KBC1009 배양액(5×108 cfu/ml)을 500배로 희석하여 10일 간격으로 3회 관주 처리한 결과 무처리대비 66.7%의 방제효과를 나타내었다.

• 한국약용작물학회지
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• 제17권2호
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• pp.125-132
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• 2009

This study was carried out to investigate the distribution of native Asparagus cochinchinensis and ecological characteristic in South Korea. Natural vegetative areas were investigated at 5 areas; Taean, Buan, Geoje, Namhae and Jindo. In this study, the $5m{\times}5m$ quadrat was established for recording coverage and appearance species by phytosociological method. The flora of the studied area in native habitats were listed as 130 species. The native habitats was classified into Pinus thunbergii community and typical community. Two communities were located in a coastal cliff and have been destroyed. Therefore Asparagus cochinchinensis native habitats must be protected by regulation. In the studied sites, soil pH, organic matter, nitrogen, available phosphorus, exchangeable K, exchangeable Ca, exchangeable Mg and cation exchange capacity were ranged from $5.1{\sim}5.7%$, $1.77{\sim}3.59%$, $0.19{\sim}0.54%$, $5.4{\sim}18.7$ (mg/kg), $0.24{\sim}0.48$ (cmol+/kg) $0.76{\sim}2.83$ (cmol+/kg), $3.11{\sim}6.22$ (cmol+/kg) and $8.7{\sim}24.5$(cmol+/kg), respectively.

• 미생물학회지
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• 제21권2호
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• pp.51-60
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• 1983

Cultural characteristics of Strptomyces griseolus isolated from the soil were investigated. This strain was disclosed to utilize D-xylose, and D-glactose in preference order as a carbon source with the formation of glucose isomerase. The addition of sweet potato starch also proved effective promoting the total enzyme activity measured at 29% higher than the control. Corn cob, one of waste agricultural resources, was hydrolyzed in 2~3% $H_2SO_4$ solution at $100^{\circ}C$, 3~5 hours to produce a xylose syrup which gave rise to the recovery of 19.9% in a batch system and 28.2% in a repeated system. By the addition of both 2% of xylose syrup(Be'28) prepared by and us 65% of corn steep liquor (total nitrogen 1.2%), enzyme induction was maximized. The enzyme activity was stimulated by the xylose and the cell growth by the C.S.L. Also, remarkable increase of enzyme activity was noticed by the addition of protein acid hydrolysate 86.2% higher than the control. $QO_2$ of the biomass cultured in 30L capacity jarfermentor recorded low oxygen requirement of 251.2 1/hr. Maximum activity of glucose isomerase was observed noted at the 9th hour after inoculation which is 2 hours faster than the stationery was observed noted at the 9th hour after inoculation which is 2 hours faster than the stationery phase of the biomass growth. Glucose isomerase from the strain was activated by adding the $Co^{++}\;and\;Mg^{++}$ with optimum temperature of $73^{\circ}C$ and pH of 7.2. Conversion ratio of 60% glucose to frutose was 42.5% after 70 hours reaction.

• 한국환경과학회지
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• 제21권8호
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• pp.989-996
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• 2012

Nitrate contamination of water environments can create serious problems such as eutrophication of rivers. Conventional biological processes for nitrate removal by heterotrophic denitrification often need additional organic substrates as carbon sources and electron donors. We tried to accelerate biological denitrification by using bioelectrochemical reactor (BER) in which electrode works as an electron donor. Denitrification activity of 8 environmental samples from various sediments, soils, groundwaters, and sludges were tested to establish an efficient enrichment culture for BER. The established enrichment culture from a soil sample showed stable denitrification activity without any nitrite accumulation. Microbial community analysis by using PCR-DGGE method revealed that dominant denitrifiers in the enrichment culture were Pantoea sp., Cronobacter sakazakii, and Castellaniella defragrans. Denitrification rate ($0.08kg/m^3{\cdot}day$) of the enrichment culture in BER with electrode poised at -0.5 V (vs Ag/AgCl) was higher than that ($2.1{\times}10^{-2}kg/m^3{\cdot}day$) of BER without any poised potential. This results suggested that biological denitrification would be improved by supplying potential throughout electrode in BER. Further research using BER without any organic substrate addition is needed to apply this system for bioremediation of water and wastewater contaminated by nitrate.

• Asian-Australasian Journal of Animal Sciences
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• 제9권6호
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• pp.615-635
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• 1996

The animal industry must be environmentally sound to ensure its long-term sustainable growth. Livestock wastes mostly manure, can be a valuable resource as well as a potential hazard to environment. The first option of manure management is developing an 'environmentally sound' feeding program and feeds so there are less excreted nutrients that need to be managed. Once the manure is produced it can be best utilized as a fertilizer of a soil conditioner. In many countries the amount of manure that can be spread on land depends on the nutrient requirements of the crop being grown. The laws specify maximum application rates and not animal stocking rates. Farmer who reduce the N and P component of manure can release pressure on the environment without having to reduce the number of animals. There are alternative system for housing and manure treatment which generate manure that are easier to handle and have less pollutants or more economic value. Treated animal waste may also be used as a feedstuff or fuel source. Most of the options of waste management result in increased costs to implement. It is necessary to assess the economics in order to find an acceptable compromise between the increased costs and the benefit to the environment. Animal welfare is also becoming more and more of an issue and it will lead to systems where animals are kept in less confined environment. The new system will have a great impact in the waste management system in the future.

• 한국환경복원기술학회지
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• 제5권6호
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• pp.24-29
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• 2002

Nitrate removal rate in three cattail wetland cells was investigated. They were a part of a pond-wetland system for stream water treatment demonstration. The system was composed of two ponds and six wetland cells. The acreage of each cell was approximately $150m^2$. The earth works for the system were finished from April 2000 to May 2000 and cattails were planted in the three cells in June 2000. Waters of Sinyang Stream flowing into Kohung Estuarine Lake were pumped into a primary pond, whose effluent was discharged into a secondary pond. The reservoir was formed by a tidal marsh reclamation project and located in southern coastal area of Korean Peninsula. Effluents from the secondary pond were funneled into the three cells. Volumes and water quality of inflow and outflow were analyzed from July 2000 through January 2001. Inflow and outflow averaged $20.2m^3/day$ and $19.8m^3/day$, respectively. Hydraulic retention time was about 1.6 days. Average influent and effluent nitrate concentration was $1.98mg/{\ell}$, $1.38mg/{\ell}$, respectively. Nitrate removal rate averaged $82.6mg\;m^{-2}\;day^{-1}$. Seasonal changes of nitrate retention rates were closely related to those of wetland cell temperatures. The average nitrate removal rate in the cells was a little lower, compared with that of $125.0mg\;m^{-2}\;day^{-1}$ for the wetlands operating in North America. This could be attributed to the initial stage of the cells and inclusion of three cold months into the seven-month study period. Root rhizosphere in wetland soils and litter-soil layers on cell bottoms could not developed. Increase of standing density of cattails within a few years will establish both root zones suitable for the nitrification of ammonia to nitrates and substrates beneficial to the denitrification of nitrates into nitrogen gases, which may lead to increase of the nitrate retention rate.

• 환경영향평가
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• 제14권4호
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• pp.165-177
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• 2005

This study was carried out to offer the basic methodology of the system and model to objectively assess the natural ecosystem for environmentally friendly land conservation and present the alternative plan on establishing the environmental policy. The results of this study were as follows. We selected four assessment factors associated with biotic, abiotic, qualitative, and functional factors. Also, there were extracted fifty-six indicators including density, total nitrogen, hemeroby degree, and goods production. The assessment factor showed that biotic one was very important. The importance of indicators were analyzed that rare and endangered plant was important in biotic factor, in case of abiotic, qualitative, and functional factors, organic matter, landscape diversity, and conservation of ecosystem were greatly important. The results of factor analysis on the characteristics of indicators, classified biotic factor into six factors including a structural one, abiotic factor as a soil and physical one, qualitative factor as five ones including hierarchical one, and functional factor as public and conservational one. In the results of analysis on assessment model, R-square of biotic factor was 51.7%, those of abiotic, qualitative, and functional one were each 58.4%, 44.2%, and 39.3%, and statistical problem was no existence. In future, to develop the assessement model and methodology of sustainable natural ecosystem, we will have to achieve the integrated model and grouping by assessment factor.

• Mycobiology
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• 제40권1호
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• pp.59-65
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• 2012

Antagonistic microorganisms against $Rhizoctonia$ $solani$ were isolated and their antifungal activities were investigated. Two hundred sixteen bacterial isolates were isolated from various soil samples and 19 isolates were found to antagonize the selected plant pathogenic fungi with varying degrees. Among them, isolate C9 was selected as an antagonistic microorganism with potential for use in further studies. Treatment with the selected isolate C9 resulted in significantly reduced incidence of stem-segment colonization by $R.$ $solani$ AG2-2(IV) in Zoysia grass and enhanced growth of grass. Through its biochemical, physiological, and 16S rDNA characteristics, the selected bacterium was identified as $Bacillus$ $subtilis$ subsp. $subtilis$. Mannitol (1%) and soytone (1%) were found to be the best carbon and nitrogen sources, respectively, for use in antibiotic production. An antibiotic compound, designated as DG4, was separated and purified from ethyl acetate extract of the culture broth of isolate C9. On the basis of spectral data, including proton nuclear magneric resonance ($^1H$ NMR), carbon nuclear magneric resonance ($^{13}C$ NMR), and mass analyses, its chemical structure was established as a stereoisomer of acetylbutanediol. Application of the ethyl acetate extract of isolate C9 to several plant pathogens resulted in dose-dependent inhibition. Treatment with the purified compound (an isomer of acetylbuanediol) resulted in significantly inhibited growth of tested pathogens. The cell free culture supernatant of isolate C9 showed a chitinase effect on chitin medium. Results from the present study demonstrated the significant potential of the purified compound from isolate C9 for use as a biocontrol agent as well as a plant growth promoter with the ability to trigger induced systemic resistance of plants.

• 한국작물학회지
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• 제42권1호
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• pp.49-55
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• 1997

맥류 성력 기계파종시 절단된 볏집을 토양 유기물원으로 환원함에 따른 맥류의 생육특성 및 토양환원 변화를 구명하고자 일련의 시험을 수행한 결과를 요약하면 다음과 같다. 1. 보리 재배시 볏짚을 토양에 투여할 경우 종자를 볏짚 밑부분에 파종하면 토양입자와 종자가 접착하게 되어 볏짚 윗부분에 종자를 파종한 경우보다 파종후 출현율이 11％ 향상되었다. 2. 볏짚을 유기물원으로 이용할 경우 퇴비시용품보다 월동전 초기생육은 부진했으나 내도복성과 천입종이 증대되었으며, 보리는 8％, 맥주보리는 20％ 각각 증수되었다. 3. 토양에 투여된 볏짚의 조기 부숙화를 위해 질소비료를 표준량보다 25％ 증비하거나, 석회 및 규산을 시용해줌으로써 볏짚 부숙율을 2∼6.9％ 높일 수 있었다. 4. 맥주보리 재배시 볏짚의 토양환원으로 천입종 및 정입율은 향상되었고, 종실의 조단백질 함량은 감소하여 곡립의 원맥 품질이 크게 향상되었다.