• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.119-122
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• 2006

In both untreated and conventionally stabilized swine manures antibiotic resistant (AR) microorganisms, Staphylococcus-like and Salmonella-like microorganisms were detected. Also pathogens with MAR phynotype were detected. Presence of such microorganisms suggest high level of pathogen-related health risk to farmers who may be in direct contact with the manure and its conventionally stabilized product In contrast the autothermal thermophilic aerobic digestion (ATAD) treatment have efficiently reduced AR and pathogenicity from the swine manure. When soil was fertilized using swine manure and its stabilized products, despite no detection of MAR-exhibiting pathogen-like microorganisms in fertilized soil, potential pathogen-related health risk could not be ruled out from the fertilized soil since the organic fertilization led to increase in AR and pathogenicity in the soil microbial communities. As conclusion, this microbiological study demonstrated that an ATAD process is applicable in control of pathogen-related health risk in livestock manure.

• 한국축산시설환경학회지
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• 제10권2호
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• pp.111-118
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• 2004

본 연구는 양돈 분뇨를 고온호기산화장치(TAO)를 이용하여 처리하였을 때, 고온 미생물 의 첨가에 의한 온도 상승과 시스템의 내부 미생물 변화 그리고 유해 미생물의 불활성화에 대하여 연구하였다. 실험은 총 용량 $18 m^3(3.0\times2.5\times2.4 m)$의 반응기에 양돈 분뇨 $6 m^3$을 투입하고 5$\~$7일간 운전하였다. 대조구는 양돈 분뇨만을 투입하였고 처리구는 6 $\iota$의 고온 미생물(Bacillus. sp)을 투입하였다. 반응기의 내부 미생물의 변화를 검토하기 위해서 호기성 중온균, 고온균 그리고 일반 세균을 분석하였다. 또한, 유해 미생물의 불활성화를 검토하기 위하여 E. coil, Salmonella. sp, Crytosporidium parvum, Giardia lamblia를 분석하였다. 대조구와 처리구의 운전기간 동안 반응기 내부의 온도 범위는 $18\~66^{\circ}C$로 $55^{\circ}C$ 이상의 높은 온도를 유지하였다. 미생물 변화에 있어서 대조구의 중온균과 고온균은 $3.1\times10^6\~1.2\times10^2$ CFU/ml, $1.0\times10^4\~8.0\times10^1$ CFU/ml로 감소하였으나 처리구의 경우, 중온균은 $3.0\times10^8\~8.6\times10^5$ CFU/ml로 감소하였으나 고온균은 $2.0\times10^6\~1.2\times10^8$ CFU/ml로 증가하는 경향을 보였다. Salmonella와 Giardia는 처리 전$\cdot$후에 검출되지 않았으며 E. coil와 Crytosporidium은 처리전 양성반응을 나타내었으나 처리 후 불활성화 되었다. 이상의 결과를 통해서, 우리는 TAO system에 고온 미생물을 첨가함으로써 유해한 미생물이 사멸된 액상비료를 생산할 수 있었고 분뇨로부터 기인하는 2차 오염을 방지할 수 있을 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제19권1호
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• pp.93-98
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• 2009

The thermophilic aerobic digestion (TAD) process is recognized as an effective method for rapid waste activated sludge (WAS) degradation and the deactivation of pathogenic microorganisms. Yet, high energy costs due to heating and aeration have limited the commercialization of economical TAD processes. Previous research on autothermal thermophilic aerobic digestion (ATAD) has already reduced the heating cost. However, only a few studies have focused on reducing the aeration cost. Therefore, this study applied a two-step aeration control strategy to a fill-and-draw mode semicontinuous TAD process. The NADH-dependent fluorescence was monitored throughout the TAD experiment, and the aeration rate shifted according to the fluorescence intensity. As a result, the simple two-step aeration control operation achieved a 20.3% reduction in the total aeration, while maintaining an effective and stable operation. It is also expected that more savings can be achieved with a further reduction of the lower aeration rate or multisegmentation of the aeration rate.

• 한국환경보건학회지
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• 제26권3호
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• pp.1-10
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• 2000

Although microorganisms play an important role in composting process, researches on the effective microorganism (EM) in composting process are rarely reported. In this study, three stages of work performed 1) investigation of composting facility 2) sample collection and isolation of the EM 3) lab-scale composting by seeding the isolated EM. For this, purpose, physical, chemical, and biological characteristics, such as temperature, moisture content, organic matter, pH population of microorganism, etc., were investigated during the process and the results were compared with those of a control(non-seeded). In the composting facility, the most active degradation of food waste was suppsed to occur in 10-11th day of composting by observing the temperature and CO2 emission. The population of bacterial and fungi was highest in thermophilic stage. Meanwhile that of actinomycetes and yeast was relatively uniform during the process. In the lab-scale test, the thermophilic stage was maintained longer(more than 9 days in 17 days of experiment) in the seeded which was favored for the high reduction of organic matter and moisture. Reduction rates of lipids and salinity were also increased in the seeded. It confirmed these results that the population of microorganisms in the seeded was observed higher in several orders than the control. However, pH of the seeded was maintained as low as about 4.5 throughout the experiment except the final period of the process. Meanwhile, pH of the control rose in the early stage of the experiment. This was probably due that the seeded microorganisms collected from the composting facility was adapted to the low pH environment.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.508-511
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• 2000

In situ hybridization with fluorescent oligonucleotides(FISH) was used to detect and localize microorganisms in the granules of lab-scale upflow anaerobic sludge blanket(UASB) reactors. An UASB reactor was seeded with mesophilically-grown($35^{\circ}\;C$) granular sludge, and thermophilically($55^{\circ}\;C$) operated by feeding with a synthetic wastewater. Sections of the granules were hybridized with 16S rRNA-targeted oligonucleotide probes for Eubacteria, Archaeabacteria, and specific phylogenetic groups of methanogens. FISH clearly showed the layed structure of thermophilic granules, which was consisted of outer bacterial cells and inner archaeal cells. Methanoseata-, Methanosarcina-like cells were also found to be localized inside the granules. These results demonstrated FISH was useful in studying the spatial organizations of methanogens and in situ morphologies and metabolic functions in thermophilic granular sludges.

• 한국환경농학회지
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• 제16권4호
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• pp.291-294
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• 1997

The purpose of this study was to investigate the change of microbial flora of using coal fly ash as humidity conditioner during the household garbage composting.The summarized results of microbial flora were as follows:There was no difference of t he seasonal fluctuation of mesophilic and themophilic microorganisms.The population of thermophilic actinomycetes was rapidly increased in winter,but not much changed in spring and summer.Thermophilic and mesophilic fungal flora were increased at the same time,but the population of thermophilic fungal flora was smaller than that of mesophilic. The population of bacteria, actinomycestes and fungi showed not much difference.

• 한국균학회지
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• 제45권1호
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• pp.43-53
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• 2017

본 연구는 양송이 배지의 관행적인 발효기술 개선에 대한 기초자료를 제공하기 위하여 배지 발효에 중요한 역할을 하는 다양한 미생물에 대한 밀도변화 및 분류학적인 특징을 밝혔고, 이들 미생물이 분비하는 세포벽 분해 관련 효소활성 변화를 조사하였다. 양송이 배지 발효와 밀접한 관련이 있는 미생물의 밀도 변화를 분석한 결과 고온성 세균, 방선균, 형광성 Pseudomonas spp., 사상균 등 다양한 미생물들이 분포하였으며, 고온성 발효가 진행됨에 유해균은 사멸되는 경향을 보였다. 야외발효 과정에서는 Psychrobacter속, Pseudomonas속, Bacillus속, Pseudoxanthomonas속이 가장 많이 분포하였고, 후발효 완료 배지에서는 Bacillus속, Psychrobacillus속이 우점하였다. 이러한 볏짚 발효 과정 중 분리한 미생물의 효소활성은 발효 초기에 cellulose 분해효소가 먼저 배지에 작용하여 탄소원을 분해한 후 hemicellulose 분해효소가 부차적으로 작용하는 양상을 보였고, 이들 효소를 분비하는 미생물들은 2차와 3차 뒤집기에서 많이 분포하였다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1986년도 추계학술대회
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• pp.509.1-509
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• 1986

Recent advances in recombinant DNA techniques have provided a tool for breeding of microorganisms of hyper production. Enzyme production by cloned microorganism has some advantages. They are ⅰ) Enzymes can be produced by a microorganism easily cultured ⅱ) Hyper production. ⅲ) In some cases, such as thermophilic enzyme gene is cloned in a mesophilic bacteria, the enzyme purification procedure can be simplified. One example, production of thermophilic ${\beta}$-galactosidase in B. subtilis will be presented. Bacillus stearothermophilus IAM 11001 produced three ${\beta}$-galactosidases, ${\beta}$-galactosidase I, II and III (${\beta}$-gal-I, II and III). By connecting restriction fragments of the chromosomal DNA to plasmid vector, followed by transformation of Escherichia coli, two ${\beta}$-galactosidase genes (bgaA and bgaB) located close to each other on the chromosome were cloned.

• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.737-743
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• 1999

A conventional thermophilic anaerobic digester was converted into a thermophilic high-rate hybrid anaerobic reactor (THAR) for treating distillery wastewater. The THAR has been operating successfully since May 1995 at a loading rate of 5.45 to $11.52{\;}kg/\textrm{m}^3/d$ (maximum of 15.02). The THAR has demonstrated a soluble Chemical Oxygen Demand (sCOD) removal efficiency of 85 to 91% and a total COD (tCOD) removal efficiency of as much as 72 to 84%. Product gas had a methane content of 59 to 68%. The tCOD removal rates were 4.31 to 5.43, 6.26 to 6.89, and 9.03 to $9.78kg{\;}tCOD/\textrm{m}^3/d$ for tapioca, com, and naked-barley wastewater, respectively. The sCOD removal rates ranged from 3.75 to 4.79,3.28 to 4.89, and 5.57 to 6.21kg $sCOD/\textrm{m}^3/d$ for tapioca, com, and naked-barley wastewater, respectively. There were unknown substances in a naked-barley distillery wastewater that were identified as being toxic for microorganisms. However, the THAR treated naked-barley wastewater continuously for 26 days, operating at an average tCOD loading of $11.08{\;}kg/\textrm{m}^3/d$without any signs of deterioration in either COD removal efficiency or gas production rate. During this period, the average removal efficiencies of tCOD and sCOD were 84% and 91%, respectively, and the gas production rate averaged 6.61 to $7.57{\;}\textrm{m}^3/\textrm{m}^3$ reactor/d which produced 0.57 to $0.69{\;}\textrm{m}^3{\;}biogas/kg{\;}tCOD_{rem}$. From tapioca and com wastewater, the reactor showed an average gas production rate of 3.18 to 3.46 and 4.91 to $5.22{\;}\textrm{m}^3/\textrm{m}^3$ reactor/d which produced 0.53 to 0.69 and 0.62 to $0.71{\;}\textrm{m}^3/kg{\;}tCOD_{rem}$, respectively.

• Bulletin of the Korean Chemical Society
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• 제25권6호
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• pp.813-818
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• 2004

A systematic study of microbial fuel cells comprised of thermophilic Bacillus licheniformis and Bacillus thermoglucosidasius has been carried out under various operating conditions. Substantial amount of electricity was generated when a redox mediator was used. Being affected by operation temperature, the maximum efficiency was obtained at 50$^{\circ}C$ with an open circuit voltage of ca. 0.7 V. While a small change around the optimum temperature did not make much effect on the cell performance, the rapid decrease in performance was observed above 70$^{\circ}C$. It was noticeable that fuel cell efficiency and discharge pattern strongly depended on the kind of carbon sources used in the initial culture medium. In the case of B. thermoglucosidasius, glucose alone was utilized constitutively as a substrate in the microbial fuel cell irrespective of used carbons sources. When B. licheniformis was cultivated with lactose as a carbon source, best charging characteristics were recorded. Trehalose, in particular, showed 41.2% coulombic efficiency when B. thermoglucosidasius was cultured in a starch-containing medium. Relatively good repetitive operation was possible with B. thermoglucosidasius cells up to 12 cycles using glucose as a carbon source, when they were cultured with lactose as an initial carbon source. This study demonstrates that highly efficient thermophilic microbial fuel cells can be constructed by a pertinent modulation of the operating conditions and by carefully selecting carbon sources used in the initial culture medium.