• 상하수도학회지
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• 제26권5호
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• pp.649-658
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• 2012

In this study, the influencing factors for efficient anaerobic digestion of high strength ammonia-nitrogen wastewater removal were investigated by testing biochemical methane potential test. In the influencing factors, the trace metals which could increase activity of anaerobic microorganisms, microbial concentration and types were evaluated. In the results, trace metals supplementation showed gas production amount higher than those without addition of trace metals. Among the tested trace metals, B, Ni, and Se were preferable to gas production. In the result of gas production according to the microbial concentration, the amount of gas production was proportional to the microbial concentration. In addition, the shortest lag time and the fastest gas production rate were achieved when the highest microbial concentration was tested. granule-type microorganism produced more gas than suspended-type microorganism. In conclusion, the efficient anaerobic digestion for high strength ammonia-nitrogen wastewater removal could be achieved by applying necessary trace metals injection and high concentration granule type microorganism.

• 미생물학회지
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• 제49권4호
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• pp.343-352
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• 2013

본 연구를 통해 유용 미생물을 적용하여 악취 저감 효과 및 조기 안정화에 미치는 영향을 알아보고자 하였다. 유기물 분해능과 악취 제어능이 뛰어난 유용 미생물 KEM을 개발하고, 이미 현장에 사용 중인 EM과 바실러스를 각각 적용하였다. 랩 스케일의 매몰지 모형 반응기를 제작하여 유용 미생물을 각각 적용한 경우와 적용하지 않은 경우(미생물을 적용하지 않고 사체만 매몰한 경우, 배지만 적용한 경우, 사체만 적용한 경우)로 나누어 실험을 진행하였다. 주기적인 수분 공급을 해줌으로써 가축 사체의 분해속도가 빨라진 것을 확인하였고, 유용 미생물을 적용한 반응기의 사체분해속도가 대조군 보다 빠른 것을 확인하였다. 가스는 총 8개의 성분(암모니아, TMA, 황화수소, 메틸머캅탄, DMS, DMDS, $CO_2$, $CH_4$)을 중점적으로 분석하였으며, 그 결과 유용 미생물을 적용하였을 경우 암모니아와 메틸머캅탄에 대하여 악취 저감 효율을 보였다. 연구에 사용되었던 토양 내에 많은 토양 미생물과 가축 사체에도 많은 미생물들이 존재하고 있어, 유용 미생물을 투입하였을 때의 뚜렷한 차이는 볼 수 없었다. 그러나 일정 부분에 한하여 악취 저감 효과와 부패 속도를 증가시키는 효과를 확인 할 수 있었다.

• 한국물환경학회지
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• 제21권2호
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• pp.118-124
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• 2005

The oxygen solubilized device(O.S.D) and standardized microorganism culture system is more efficient than physical and chemical purification techniques in closed water. This study was to determine how the O.S.D and standardized culture system is efficient in purification capacity in closed water based on the lab scale and pilot plant. In the batch test, inducing the quantitative results from pilot plant operation condition, removal efficiency of COD and TN were about 48.3% and 35% respectively, while SS and chlorophyll-a were 94.9% and 68.7%. The pilot plant results showed that suspended solid(SS) and chlorophyll-a removal efficiency were 60% and 59% respectively, due to coagulation characteristics by standardized culture. Total nitrogen(TN) and total phosphorus(TP)showed good effect for the purification of target pond water quality from field data. Additionally, released velocity was determined in control condition of $5.31mgPO{_4}^{3-}{\cdot}m^{-2}{\cdot}day^{-1}$ and $2486.8mgCOD{\cdot}m^{-2}{\cdot}day^{-1}$. Otherwise, phosphate and COD reflux in the aeration and microorganism condition was showed $-9.95mgPO{_4}^{3-}{\cdot}m^{-2}{\cdot}day^{-1}$ and $-397.88mgCOD{\cdot}m^{-2}{\cdot}day^{-1}$. This technology is the most effective not only removal of SS and chlorophyll-a but also control of phosphate and COD release which is very important phenomena in evaluating water quality in closed water like a reservoir and pond.

• Advances in concrete construction
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• 제10권4호
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• pp.357-367
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• 2020

The impulse of this paper is to examine the influence of unsteady flow comprising of Eyring-Powell nanofluid over a stretched surface. This work aims to explore efficient transfer of heat in Eyring-Powell nanofluid with bio-convection. Nanofluids possess significant features that have aroused various investigators because of their utilization in industrial and nanotechnology. The influence of including motile microorganism is to stabilize the nanoparticle suspensions develop by the mixed influence of magnetic field and buoyancy force. This research paper reveals the detailed information about the linearly compressed Magnetohydrodynamics boundary layer flux of two dimensional Eyring-Powell nanofluid through disposed surface area due to the existence of microorganism with inclusion the influence of non- linear thermal radiation, energy activation and bio-convection. The liquid is likely to allow conduction and thickness of the liquid is supposed to show variation exponentially. By using appropriate similarity type transforms, the nonlinear PDE's are converted into dimensionless ODE's. The results of ODE's are finally concluded by employing (HAM) Homotopy Analysis approach. The influence of relevant parameters on concentration, temperature, velocity and motile microorganism density are studied by the use of graphs and tables. We acquire skin friction, local Nusselt and motil microorganism number for various parameters.

• BMB Reports
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• 제46권12호
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• pp.575-581
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• 2013

Lipid droplet (LD) is a cellular organelle that stores neutral lipids as a source of energy and carbon. However, recent research has emerged that the organelle is involved in lipid synthesis, transportation, and metabolism, as well as mediating cellular protein storage and degradation. With the exception of multi-cellular organisms, some unicellular microorganisms have been observed to contain LDs. The organelle has been isolated and characterized from numerous organisms. Triacylglycerol (TAG) accumulation in LDs can be in excess of 50% of the dry weight in some microorganisms, and a maximum of 87% in some instances. These microorganisms include eukaryotes such as yeast and green algae as well as prokaryotes such as bacteria. Some organisms obtain carbon from $CO_2$ via photosynthesis, while the majority utilizes carbon from various types of biomass. Therefore, high TAG content generated by utilizing waste or cheap biomass, coupled with an efficient conversion rate, present these organisms as bio-tech 'factories' to produce biodiesel. This review summarizes LD research in these organisms and provides useful information for further LD biological research and microorganism biodiesel development.

• 대한의생명과학회지
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• 제28권3호
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• pp.145-156
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• 2022

Over the past few decades, few technologies have had a greater impact on clinical microbiology laboratories than matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF MS). The MALDI-TOF MS is a fast, accurate, and low-cost and efficient method of microbial identification. This technology generates characteristic mass spectral fingerprints that is a unique signature for each microorganism, making it an ideal method for accurate identification at the genus and species levels of both bacterial and fastidious microorganism such as anaerobes, mycobacterium and fungi etc. In addition, MALDI-TOF MS has been successfully used in microbial subtyping and susceptibility tests such as determination of resistance genes. In this study, the authors summarized the application of MALDI-TOF MS in clinical microbiology and clinical research and explored the future of MALDI-TOF MS.

• 한국식품위생안전성학회지
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• 제29권3호
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• pp.189-194
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• 2014

본 연구의 목적은 식중독으로 인한 지속적인 위해 발생을 예방하기 위하여 학교의 급식시설 및 집기류에서 미생물 오염수준을 분석하고자 하였다. 그 결과, 총 세균 측정용 배지에서 $12.3{\pm}2.6$건으로 가장 많은 미생물이 배양되었고, 황색포도상구균 측정용 배지에서 $10.3{\pm}3.9$건과 대장균 측정용 배지에서 $9.5{\pm}3.9$건으로 미생물이 배양되었다. 그러나 비브리오 측정용 배지에서는 $1.5{\pm}1.0$건으로 가장 적은 미생물이 배양되었다. 급식시설 및 집기류에서 미생물 오염이 심한 곳은 전처리실 바닥으로 $4.5{\pm}0.6$건으로 가장 높고, 조리실 바닥도 $4.3{\pm}1.0$건으로 나타났다. 다음으로 조리대가 $3.3{\pm}1.0$건으로 나타났으며, 급식식탁에서도 $3.0{\pm}0.0$건으로 상당히 높은 미생물 오염을 확인할 수 있었다. 반면에 집기류에서는 시설들에 비하여 낮은 미생물 오염도를 보였다. 칼과 도마를 사용용도에 따라 구분하여 미생물을 분석한 결과, 생선용 칼에서 $2.0{\pm}0.8$건과 생선용 도마에서 $1.3{\pm}1.5$건으로 다른 용도에 비하여 약간 높은 미생물 오염도를 보였다. 배양된 미생물들을 동정한 결과, 다양한 미생물들이 오염되어 있으며 일부는 2번 이상씩 반복하여 검출되었다. 특히, 주요 식중독균인 Staphylococcus aureus는 조리대, 트렌치, 칼에서 3번에 걸쳐서 확인되었다. 또한 주요 식중독균에 속하는 Bacillus cereus가 칼에서 확인되었으며, 자연에 널리 분포하면서 때로는 급성폐렴을 일으키기도 하는 Klebsiella pneumoniae는 4번 반복하여 검출되었다. 위의 결과를 종합하여 보면, 황색포도상구균을 비롯한 주요 식중독균뿐만 아니라 식품의 부패를 일으키는 미생물들이 학교급식의 시설 및 집기류에 오염되어 있다는 것을 확인 할 수 있었다. 그러므로 학교급식의 안전성을 확보하고 학생들의 건강을 증진시키기 위하여 더욱 철저한 개인위생 및 효율적이고 체계적인 시설 관리가 이루어져야 할 것으로 사료된다

• Mycobiology
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• 제49권5호
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• pp.491-497
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• 2021

An endolichenic fungus Xylaria grammica EL000614 produces grammicin, a potent nematicidal pyrone derivative that can serve as a new control option for root-knot nematodes. We optimized an Agrobacterium tumefaciens-mediated transformation (ATMT) protocol for X. grammica to support genetic studies. Transformants were successfully generated after co-cultivation of homogenized young mycelia of X. grammica with A. tumefaciens strain AGL-1 carrying a binary vector that contains the bacterial hygromycin B phosphotransferase (hph) gene and the eGFP gene in T-DNA. The resulting transformants were mitotically stable, and PCR analysis showed the integratin of both genes in the genome of transformants. Expression of eGFP was confirmed via fluorescence microscopy. Southern analysis showed that 131 (78.9%) out of 166 transformants contained a single T-DNA insertion. Crucial factors for producing predominantly single T-DNA transformants include 48 h of co-cultivation, pretreatment of A. tumefaciens cells with acetosyringone before co-cultivation, and using freshly prepared mycelia. The established ATMT protocol offers an efficient tool for random insertional mutagenesis and gene transfer in studying the biology and ecology of X. grammica.

• 대한환경공학회지
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• 제36권4호
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• pp.277-285
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• 2014

본 연구에서는 구제역으로 인해 발생된 가축사체 매몰지의 조기 안정화를 위하여 유용 미생물 KEM을 사용하였고, 토질에 따른 효과를 알아보기 위하여 매몰지 모형의 반응기를 통해 연구하였다. 반응기는 랩 스케일로 제작하였고, 토질 특성에 다양성을 주기 위하여 일반 토양, 20%의 사토와 섞은 일반 토양, 20%의 점토와 섞은 일반 토양을 각각 준비하였다. 각각의 토양과 유용 미생물 KEM과 섞은 후 사체를 매몰하였다. 분석 대상 악취 성분은 총 8가지로 이산화탄소, 메탄, 암모니아, 트리메틸아민, 황화수소, 메칠메르캅탄, 황화메틸과 이황화메틸이었다. 악취 분석 결과 황화수소와 메틸메르캅탄은 사토를 적용한 반응기에서 저감 효과를 보였고(각각 배출 잔량 0.09, 0.35 mg), 암모니아와 트리메틸아민은 점토를 적용한 경우 저감 효율이 높았다(각각 배출잔량 0.31, 2.06 mg). 이에 근거하여 사토는 황 화합물 악취 저감에, 점토는 질소 화합물 악취 저감에 효과를 나타내는 것으로 보인다. 또한, 토질의 특성에 따라 우점화된 미생물의 군집과 분포도가 변화되는 것을 확인하였다.

• 한국환경보건학회지
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• 제28권5호
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• pp.22-27
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• 2002

The composting practice has been recognized as the most popular way of controlling food waste and many attempt have been made in the field to establish more efficient and economical process. Some of the efforts are mixing cured compost with sawdust as alternative bulking agent, seeding commercially produced microorganism and/or combination of above. However, verification of such efforts is often restricted because of either the lack of engineering consideration on the limitation of composting facility scales. In this study, the effect of mixing materials in food waste composting was investigated by controlling the combination and the mixing ratio of them. When the cured compost was mixed with saw dust. the decomposition of organic material was proven to be more active by observing the compost temperature, the oxygen (O$_2$) consumption, and the cumulative carbon dioxide ($CO_2$) profile. However, the quantity of compost mix-ing seemed not to influence the reaction as long as the minimum required amount was mixed. The feeding of com-mercially produced microorganism had a tendency to prolong the thermophilic stage, which helped to increase the decomposition but it resulted in composting period. Regardless of the composting condition, bacteria and actinomycetes increased in population as the reaction approached to the end. The population of bacteria and actinomycetes were rel-atively higher than those of fungi and yeast throughout the reaction.