• 한국식품저장유통학회지
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• 제19권3호
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• pp.323-327
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• 2012

신선절단 '쓰가루' 사과의 갈변과 미생물 성장 저해에 대해 ascorbic acid와 초음파 처리의 효과를 조사하였다. 사과를 8조각으로 자르고, 1분간 증류수에 침지(Cont), 1분 동안 1% ascorbic acid에 침지(AA), 1분 동안 초음파 처리(US), 또는 1분 동안 1% ascorbic acid용액으로 초음파 처리(AA+US) 후 0.04 mm polypropylnene film으로 열접합 포장하고, 8일 동안 $10^{\circ}C$에서 저장하면서 품질 변화를 분석하였다. AA+US 처리구에서 저장 마지막 날까지 가장 높은 $L^*$값과 낮은 $a^*$, $b^*$값을 보였고, polyphonoloxidase 활성 또한 가장 억제 된 것으로 나타났다. 총균수의 변화는 저장 초기부터 마지막 날까지 AA+US 처리구에서 미생물 성장이 가장 저해된 것으로 나타났다. 가용성 고형분 함량, 적정산도 및 pH 등은 처리조건에 따른 큰 차이를 보이지 않았다. 따라서 ascorbic acid와 초음파의 병용 처리는 신선 절단 사과의 효소적 갈변을 억제하고, 미생물 성장을 저해하는 효과를 가지는 것으로 확인되었다.

• 한국미생물·생명공학회지
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• 제42권2호
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• pp.202-206
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• 2014

본 연구에서는 감가공 과정에서 매년 막대한 양으로 발생하는 감껍질을 이용하여 에탄올을 생산하기 위하여 묽은 황산으로 감껍질을 전처리하는 조건을 중심합성계획법과 반응표면분석법을 통하여 최적화하였다. 감껍질의 최적 전처리 조건은 황산농도 1.77%와 열처리 시간 26.4분이었으며 RSM 모델에서 예측한 수준과 비슷한 수율로 환원당을 생성하였다. 감껍질 전처리물을 이용한 효모발효에서 혐기적 배양조건에서 15.52 g/l의 에탄올이 생산되는 것을 확인하였다. 본 연구를 통하여 매년 막대한 양으로 발생하는 감껍질을 활용하는 방안 중의 하나로써 효모를 이용한 에탄올 생산의 가능성을 제시하였다.

• Journal of Microbiology and Biotechnology
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• 제30권9호
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• pp.1321-1334
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• 2020

Beef, pork, chicken and milk are considered representative protein sources in the human diet. Since the digestion of protein is important, the role of intestinal microflora is also important. Despite this, the pure effects of meat and milk intake on the microbiome are yet to be fully elucidated. To evaluate the effect of beef, pork, chicken and milk on intestinal microflora, we observed changes in the microbiome in response to different types of dietary animal proteins in vitro. Feces were collected from five 6-week-old pigs. The suspensions were pooled and inoculated into four different media containing beef, pork, chicken, or skim milk powder in distilled water. Changes in microbial communities were analyzed using 16S rRNA sequencing. The feces alone had the highest microbial alpha diversity. Among the treatment groups, beef showed the highest microbial diversity, followed by pork, chicken, and milk. The three dominant phyla were Proteobacteria, Firmicutes, and Bacteroidetes in all the groups. The most abundant genera in beef, pork, and chicken were Rummeliibacillus, Clostridium, and Phascolarctobacterium, whereas milk was enriched with Streptococcus, Lactobacillus, and Enterococcus. Aerobic bacteria decreased while anaerobic and facultative anaerobic bacteria increased in protein-rich nutrients. Functional gene groups were found to be over-represented in protein-rich nutrients. Our results provide baseline information for understanding the roles of dietary animal proteins in reshaping the gut microbiome. Furthermore, growth-promotion by specific species/genus may be used as a cultivation tool for uncultured gut microorganisms.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1999년도 정기총회 및 춘계 공동 학술발표회
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• pp.149-156
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• 1999

In the United States (U.S.), the monitored natural attenuation (MNA) approach has been used as an alternative remedial option for organic and inorganic compounds retained in soil and dissolved in groundwater. The U.S. Environmental Protection Agency (EPA) defines the MNA as“in-situ naturally-occurring processes include biodegradation, diffusion, dilution, sorption, volatilization, and/or chemical and biochemical stabilization of contaminants and reduce contaminant toxicity, mobility or volume to the levels that are protective of human health and the environment”. The Department of Soil Environment. National Institute Environmental Research (NIER) is in the process for demonstrating the MNA approach as a potential remedial option for the BTEX contaminated site in Uiwang City. The project is charactering the research site in terms of the nature and extend of contamination, biological degradation rate, and geochemical and hydrological properties. The microbial-degradation rate and effectiveness of nutrient and redox supplements will be determined through laboratory batch and column tests. The geochemical process will be monitored for determining the concentration changes of chemical species involved in the electron transfer processes that include methanogenesis, sulfate and iron reduction, denitrification, and aerobic respiration. Through field works, critical soil and hydrogeologic parameters will be acquired to simulate the effects of dispersion, advection, sorption, and biodegradation on the fate and transport of the dissolved-phase BTEX plume using Bioplume III model. The objectives of this multi-years research project are (1) to evaluate the MNA approach using the BTEX contaminated site in Uiwang City, (2) to establish a standard protocol for future application of the approach, (3) to investigate applicability of the passive approach as a secondary treatment remedy after active treatments. In this presentation, the overall picture and philosophy behind the MNA approach will be reviewed. Detailed discussions of the site characterization/monitoring plans and risk-based decision-making processes for the demonstration site will be included.

• Journal of Microbiology
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• 제41권1호
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• pp.34-40
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• 2003

Aspergillus nidulans, a homothalic ascomycete, has a complete sexual reproductive cycle as well as an asexual one. Both sexual and asexual development are known to be genetically programmed, but are also strongly affected by environmental factors including nutrients, light, temperature and osmolarity. We have examined these factors to define favored conditions for fruiting body (cleistothecium) formation. In general, fruiting body formation was enhanced where carbon and nitrogen sources were sufficient. Limitation of C-source caused predominant asexual development while inhibiting sexual development. When higher concentrations of glucose were supplied, more cleistothecia were formed. Other carbon sources including lactose, galactose and glycerol made the fungus develop cleistothecia very well, whereas acetate caused asexual sporulation only. Organic nitrogen sources like casein hydrolysate and glycine, and an increase in nitrate or ammonium concentration also enhanced sexual development. In addition to nutrient effects, low levels of aerobic respiration, caused either by platesealing or treatment with various chemicals, favored sexual development. Carbon limitation, light exposure and a high concentration of salts promoted asexual development preferentially, suggesting that stress conditions may drive the cell to develop asexual sporulation while comfortable and wellnourished growth conditions favored sexual development.

• 미생물학회지
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• 제32권2호
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• pp.163-171
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• 1994

경유를 sandy loam 토양에서 농도별로 투여하여 토양미생물군집에 미치는 영향을 조사하였으며 또한 경우가 첨가된 토양에서 경유의 신속한 제거를 위해 실시한 bioremediation에 의한 영향을 측정하였다. 경유는 토양에서 16주 후 약 50% 내외의 잔류량을 나타내며 bioremediation 처리시 제거율은 60~95% 정도가 증가하여 16주 후 약 8~20 범위의 잔류량을 나타내었다. 토양에 경유가 첨가되었을 때에는 세균직접계수, 진균류의 균사 길이, 호기성 종속영양세균과 탄화수소 분해세균의 수가 최고 10 내지 100배 정도 증가하였다. Bioremediation 처리시에는 그 증가가 더욱 두드러져 각종 미생물 개체수 측정치가 최고 100배 내지 1000배까지 증가하였다. 경유가 fluorescein diacetate 가수분해 활성에 미치는 영향은 bioremediation 처리를 하지 않은 토양에서는 뚜렷한 증감의 경향이 없었으나 bioremediation 처리를 한 토양에서는 10배 내외의 활성의 증가를 보였으며 이러한 양상은 soil dehydrogenase 활성에서도 유사하게 나타났다.

• 상하수도학회지
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• 제16권6호
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• pp.670-678
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• 2002

Since Korean government imposed a stricter regulation on effluent T-N and T-P concentrations from wastewater treatment plant, a new process has to be developed to meet these rules and this process should remove T-N and T-P, economically, from weak wastewater that is typical for Korea's combined sewer system sewage. In this study, a computer simulator, BioWin from EnviroSim, Inc. was used. Three processes - A2/O, Modified Johannesburg, UCT- had been simulated under same operational conditions and a new process - Parallel BNR Process - had been developed based on these simulation results. The Parallel BNR process consists of two rows of reactors: One row has anaerobic and aerobic reactors in series, and the other row has RAS anoxic1 and RAS anoxic2 reactors in series. In order to ensure anaerobic state in anaerobic tank, a part of influent is fed to RAS anoxic1 tank in second row. This process had been simulated under same conditions of other three processes and the simulation results were compared. The results showed that three existing processes could not perform biological phosphorus removal when the average influent was fed at any operation temperatures. However, the Parallel BNR process was found that biological phosphorus removal could be performed when both design and average influent were fed at any operation temperatures. This process showed the T-N concentration in effluent had a maximum value of 15mg/L when design influent was fed at $13^{\circ}C$ and a minimum value of 14mg/L when average influent was fed at $20^{\circ}C$. Also, T-P concentrations had a maximum value of 1.3mg/L when average influent was fed at $20^{\circ}C$ and a minimum value of 1.1mg/L when design influent was fed at $13^{\circ}C$. Based on these results, we found that this process can remove nitrogen and phosphorus biologically under any operational conditions.

• 한국축산시설환경학회지
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• 제9권1호
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• pp.45-56
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• 2003

$TAO^{TM}$ System is an auto-heated thermophilic aerated digestion process using a proprietary microbe called as a Phototropic Bacteria (PTB). High metabolic activity results in heat generation, which enables to produce a pathogen-free and digested liquid fertilizer at short retention times. TAO$^{TM}$ system has been developed to reduce a manure volume and convert into the liquid fertilizer using swine manure since 1992. About 100 units have been installed and operated in Korean swine farms so far. TAO$^{TM}$ system consists of a reactor vessel and ejector-type aeration pumps and foam removers. The swine slurry manure enters into vessel with PTB and is mixed and aerated. The process is operated at detention times from 2 to 4 days and temperature of 55 to $65^{\circ}C$. Foams are occurred and broken down by foam removers to evaporate water contents. Generally, at least 30% of water content is evaporated, 99% of volatile fatty acids caused an odor are removed and pathogen destruction is excellent with fecal coliform, rotavirus and salmonella below detection limits. The effluent from TAO$^{TM}$ system, called as the "TAO EFFLUX", is screened and has superb properties as a fertilizer. Normally N-P-K contents of screened TAO Efflux are 4.7 g/L, 0.375 g/L and 2.8 g/L respectively. The fertilizer effect of TAO EFFLUX compared to chemical fertilizer has been demonstrated and studied with various crops such as rice, potato, cabbage, pumpkin, green pepper, parsley, cucumber and apple. Generally it has better fertilizer effects and excellent soil fertility improvement effects. Moreover, the TAO EFFLUX is concentrated through membrane technology without fouling problems for a cost saving of long distance transportation and a commercialization (crop nutrient commodity) to a gardening market, for example.

• 한국식품과학회지
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• 제49권4호
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• pp.408-414
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• 2017

본 연구에서는 PEF 처리 시간과 전기장 세기가 증가할수록 주스 내 토착 미생물 저해 효과가 상승함을 알 수 있었고, 또한 처리 주스의 주입 온도를 높여 $40^{\circ}C$에서 PEF 처리했을 때 살균 효과가 높아짐을 확인하였다. 상온 PEF와 중온 PEF 처리 모두 감귤 주스와 당근 주스의 이화학적 영양학적 특성에 크게 영향을 주지 않으면서도 상업적 살균에 적합한 미생물 저해 효과를 보여주었다. 본 연구는 파일럿 규모의 PEF 처리 장비를 이용하여 감귤 주스와 당근 주스를 살균하지 않은 주스의 품질을 유지하면서 살균할 수 있음을 보여주었다. 처리 시간, 전기장 세기, 그리고 주입 온도의 조절을 통해 최소의 에너지 사용으로 품질 보존과 동시에 최대의 미생물 저해 효과를 얻는 PEF 살균 공정 최적화가 다양한 주스 제품에 대하여 이루어 질 수 있을 것으로 전망한다.

• 한국축산식품학회지
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• 제29권6호
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• pp.680-684
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• 2009

The effects of garlic and onion on the microbiological and physicochemical properties of irradiated ground beef patties were evaluated. Ground beef was mixed with 0.5%(w/w) minced garlic or 2.5%(w/w) minced onion, vacuum-packed in oxygen-impermeable nylon/PE bags and then electron beam-irradiated at 2.5 kGy. All samples were kept at $4^{\circ}C$ for 8 d. Irradiation resulted in a 2-log CFU/g reduction in both aerobic and coliform bacteria. The microbial counts gradually increased during storage, but those in beef that contained garlic or onion were 1-log CFU/g lower than those of the control samples after 8 d of storage. The pH value decreased during storage in all meat samples, but this decrease was greater in non-irradiated beef than in irradiated beef. The lipid oxidation, volatile basic nitrogen content and Hunter color values of raw patties were generally not affected by irradiation or the addition of garlic and onion. Sensory evaluation of cooked patties showed that the off-odor was less pronounced in samples that contained added garlic or onion than in control samples, and that the overall acceptability of beef formulated with garlic was the highest. Overall, the results of this study indicate that the addition of garlic or onion in combination with irradiation treatment enhanced the microbial quality and improved the sensory quality of irradiated ground beef.