대청호 퇴적층의 미생물 분포 밀도

박동진,육연수,박대균,이상화,오희목,김창진,Park, Dong-Jin,Yuk, Youn-Su,Park, Dae-Gyun,Lee, Sang-Hwa,Oh, Hee-Mock,Kim, Chang-Jin 한국미생물학회 1998 미생물학회지 Vol.34 No.4

대청호 퇴적층에 부존하는 미생물들의 분포 양상을 알아보기 위해 대전광역시 동구 추동 대전 취수탑(정체수역) 부근과 충청북도 보은군 회남면 어성리 회남교(본류수역) 부근의 두 지점으로부터 0.5~2 cm와 19~21 cm의 두 깊이에서 장마 전(1998년 5월)과 후(1998년 8월)에 각각 퇴적토를 채집하여 세균, 방선균, 진균의 분포 밀도를 측정하였다. 조사된 모든 미생물군들은 정체수역 보다 본류수역에서 평균 3.9배 더 높게 분포하였으며, 또한 각 수역에서 세균은 장마 전후에 큰 차이가 없었으나 방선균은 장마 후에, 진균은 장마 전에 더 높게 나타났다. 그리고 미생물들의 분포 밀도는 퇴적층의 길이가 깊어짐에 따라 큰 감소를 나타내지 않았으며 오히려 일부 심층에서는 표층보다 더 높게 나타났다. 대청호 인근의 초지 지역과 비교하였을 때, 세균, 방선균, 진균의 분포 밀도는 각각 52.9%, 35%, 7%로 나타났다. 또한 대청호 접경 지점과 비교하였을 때, 세균과 방선균은 각각 1.89배 및 3.63배 더 높았으나 진균은 71.2%의 낮은 분포 수준을 나타내었다. In order to characterize the microbial distribution at sediments of Lake Daechung, soil samples were collected at two depths of 0.5~2 cm and 19~21 cm of Chudong(static) and Hoenam(streaming) site on May 18th(before rainy season) and on August 24th in 1998(after rainy season), and then the density(CFU/g soil) of microorganisms including bacteria, actinomycetes, and fungi was investigated by the viable cell counting method. Microbial density at streaming site was on the whole 3.9-fold higher than that at static site. Bacterial densities examined before and after rainy season was revealed to be similar, whereas actinomycetes and fungi exhibited higher distribution after and before rainy season, respectively. The microbial distribution was not generally reduced with the increase of depth and was rather higher at some deep sites. On comparing with the microbial densities of grass land around the lake, bacteria, actinomycetes, and fungi at lake sediments on the average showed the distribution of 52.9%, 35%, and 7%, respectively. However, their distribution except for fungi which exhibited 71.2% was mostly found to be somewhat higher than at the shore of lake.

Distribution Functions Describing the Microbiological Contamination of Seasoned Soybean Sprouts

Jin Pyo Park,Dong Sun Lee,Hyun-Dong Paik 한국식품과학회 2008 Food Science and Biotechnology Vol.17 No.3

Different statistical distribution functions were examined to find an adequate distribution function to describe the microbial contamination behavior of a Korean side dish product, seasoned soybean sprouts for different seasons and market groups. The triang distribution was the best for any market groups in winter, while the logistic distribution could describe the microbial contamination in log CFU/g for all the market groups in spring and summer. From parametric bootstrapping based on the fitted distributions, it was found that a normal distribution could describe the distribution of mean microbial count in log CFU/g for all the seasons and market groups. Statistical parameters for each season/market group are presented to estimate the confidence interval.

전처리 농산물의 유통 경로에 따른 미생물학적 오염도 조사

현정은,이수빈,정도영,채효빈,최송이,황인준,김세리 한국식품영양과학회 2023 한국식품영양과학회지 Vol.52 No.3

This study investigates microbial contamination in pre-treated agricultural products. Eleven types of pre-treated agricultural product were evaluated for microbial contamination arising from four distribution channels: supermarket, local market, online, and traditional market. Of the 38 samples examined, the average populations of total aerobic bacteria and coliform in sliced garlic were higher by 6.85 and 5.94 log CFU/g, respectively. Similarly, the average populations of total aerobic bacteria and coliform determined in shredded green onion were 6.39 and 5.46 log CFU/g, respectively. In particular, the average populations of total aerobic bacteria were higher in sliced garlic and shredded green onion than in peeled garlic and peeled green onion. Furthermore, Bacillus cereus (13.16%) was detected in peeled chestnut, peeled potato, cut Chinese yam, and cut green onion. In addition, Staphylococcus aureus was isolated from cut radish in 1 out of 38 samples (2.63%). However, no correlation was obtained between microbial population and distribution channel in all samples. These results could provide the basic information to control the microbial safety of pre-treated agricultural products.

Effect of Improving Quality by Changing the Distribution Method of Shrimp Culture

Woo-Taeg KWON,Min-Jae JUNG,Hyun-Jin Woo,Woo-Sik LEE,Lee-Seung KWON 한국유통과학회 2021 유통과학연구 Vol.19 No.4

Purpose: This study focuses on exploring ways to improve the distribution method of shrimp farming so that it is eco-friendly and increases the distribution of shrimp. Research design, data and methodology: The experimental device installed in a biofloc shrimp culture in one area tested 10 times. Complex odor, concentration of H2S, water quality improvement effected by decomposition of organic substances, and degree of microbial activation measured. The data of the experimental results verified using the T-test technique, and the p value was determined based on the significance probability of 0.05. Results: This experimental device was effective in reducing odor and hydrogen sulfide in shrimp farms. With the improvement of water quality, dissolved oxygen increased due to the microbubble and cavitation action of air ejector and ultrasonic waves. In addition, the cultured microorganisms in the cultured water treated by the experimental device were remarkably proliferated compared to the raw water. Conclusions: The biofloc distribution method has a significant effect on improving water quality and reducing odor substances and will become a new eco-friendly and efficient distribution method for shrimp farming in the future.

Distribution of Airborne Microorganisms in Yellow Sands of Korea

Choi, Dae-Sung,Park, Yong-Keun,Oh, Sang-Kon,Yoon, Hee-Ju,Kim, Jee-Cheon,Seo, Won-Jun,Cha, Seung-Hee The Microbiological Society of Korea 1997 The journal of microbiology Vol.35 No.1

Distribution of airborne microorganisms was determined with two different types of air samplers, the Anderson cascade sampler and the Aerobioscope sampler, in the vicinity of Taejon. The size distribution of particles carrying bacteria and fungi was concurrently measured. The concentration of detected viable airborne particles was greatly varied. It was observed that the number of microbial particles increased in April and October. The most isze o particles carrying bacteria was larger than 4.7 .mu.m in mean aerodiameter, which made up 69.8% of the total particle fraction. About 63.2% of fungi-carrying particles were smaller than 4.7 .mu.m in aerodiameter. The distribution of particles on Yellow Sand Phenomena days was also analyzed. The number of fine particles having mass median aero-diameter from 1.0 to 10.mu.m increased on Yellow Sand Phenomena days to about 6 times that on normal days and the n umber of colony forming unit (CFU/$\textrm{m}^3$) of airborne bacteria also increased by 4.3 times in April. The reuslts from the Anderson sampler showed that the concentration of bacteria increased greatly on the fraction of fine particles ranging from 0.6 $\mu$m to 4.7 $\mu$m in diameter. Unlike the increase in bacterial floraon Yellow Sand Phenomena days, the fungal concentration slightly decreased and showed a normal size distribution parttern. This study suggests that a long-range transmission of bacteria results form bacteria adsorbing onto the fine particles during the Yellow Sand Phenomena.

식품산업체에서 확률분포 모델을 이용한 불규칙적인 미생물 수 분포 활용

박경진,김성조,심우창,천석조,최원상,홍종해 한국식품위생안전성학회 2003 한국식품위생안전성학회지 Vol.18 No.4

식품산업체에서 검사한 자료의 일반세균수는 대부분 불규칙 분포를 나타낸다. 최근 이러한 불규칙적인 경향에 대하여 미생 물수의 lognormal 분포 특성을 이용하는 확률분포 모델을 적용함으로써 좀더 정확한 변화의 특성을 밝히고 있다. 확률분포 모델을 이용하면 일반세균수와 대장균군 등의 분석결과에 대해 과거의 단순한 경향분석을 벗어나, 유용한 분석이 가능한 것으로 나타나고 있 다. 본 연구는 냉동만두류를 생성하는 2개 업체의 각각 1년 동안 실험된 일반세균 자료를 갖고, 확률분포 모델 활용의 타당성과 업체간의 위생수준 상호비교 그리고 예상되는 위해 발생 예측에 적용 검토하였다. 그 결과 정량적인 미생물 자료에 대한 확률분포 모델의 적용은 식품산업체에서 일반세균수에 의한 위해발생 가능성을 예측하고 안전관리 수준을 결정하는데 유용한 것으로 판단되었다. Sequences of industrial microbial counts of foods shows irregular fluctuating patterns as a definition of fluctuating microbial counts(FMC). Recently, it became clear that the FMC was considered as having a lognormal distribution as first order approximation. Application of lognormal distribution to the industrial microbial counts could produce useful information in practice. This study is intended to verify the application method of lognormal distribution in FMC. The one year's records of microbial counts of frozen dumplings from two companies were obtained, and the statistical analysis was carried out to estimate the frequencies of future events where counts exceeding selected levels and to compare the sanitation level of the two companies. The results showed that this application method enable translation of irregular records of microbial counts into an useful information such as the actual probabilities of outburst of a given level and the quantitative predictions of potential hazards in the processing.

국내 식품냉장창고 온도분포 분석 및 적정 확률분포모델 설정

김형태,박경진,김상규,백옥진 한국식품위생안전성학회 2012 한국식품위생안전성학회지 Vol.27 No.3

This study was to present the proper probability distribution models that based on the data for surveys of food cold storage temperatures as the input variables to the further MRA (Microbial risk assessment). The temperature was measured by directly visiting 7 food plants. The overall mean temperature for food cold storages in the survey was 2.55 ± 3.55oC, with 2.5% of above 10oC, −3.2oC and 14.9oC as a minimum and maximum. Temperature distributions by space-locations was 0.80 ± 1.69oC, 0.59 ± 1.68oC, and 0.65 ± 1.46oC as an upper (2.4~4 m), middle (1.5~2.4 m), and lower (0.7~1.5 m), respectively. Probability distributions were also created using @RISK program based on the measured temperature data. Statistical ranking was determined by the goodness of fit (GOF) to determine the proper probability distribution model. This result showed that the LogLogistic (−4.189, 5.9098, 3.2565)distribution models was found to be the most appropriate for relative MRA conduction.

Impacts of Cropping Systems on the Distribution of Soil Microorganisms in Mid-mountainous Paddy

Ui-Gum Kang,Woon-Chul Shin,Jong-Seo Choi,Yong-Bok Lee,Young-Han Lee 한국토양비료학회 2016 한국토양비료학회지 Vol.49 No.5

Soil microbes are widely well known to play an important role for sustainable agriculture in terms of crop healthy cultivation and environmental conservation. In this context, the distributional characteristics of soil microbes according to cropping systems were investigated under rice (R)-rice (R), rice (R)-barley (B)-rice (R), and soybean (S)-barley (B)-soybean (S) cropping condition to get basic informations for sustainable agriculture, where barley was grown for winter, in mid-mountainous loam paddy located at the altitude of 285 m above sea level in Sangju area from 2014 to 2015. Estimating from microbial communities by fatty acid methyl ester (FAME) method, a total biomass of bacteria, actinomycetes, and fungi in R-B-R plot was 37% and 40% higher than that in S-B-S and R-R plots, respectively (p < 0.05). In especial, bacteria and fungi were more in R-B-R plot than those in any other ones. B. japonicum, AMF, and mesophilic Bacillus sp. were also greater in S-B-S plot than those. In the community distribution, however, bacteria and actinomycetes showed comparatively high values in S-B-S plot relative to either R-R or R-B-R plot including rice, in which fungi outstanding. In the correlation between microbial biomass and soil properties changed by the cropping, bacteria was positively correlated with C:N ratio; actinomycetes with exchangeable Ca; fungi with available P₂O5 (p < 0.05). While these microbes showed negative response to water stable aggregates of soil.

염소수 세척이 ‘다채’ 어린잎 채소의 품질 및 미생물에 미치는 영향

이정수(Jung-Soo Lee),김지강(Ji-Gang Kim),박수형(Suhyung Park) 한국원예학회 2009 원예과학기술지 Vol.27 No.4

This experiment was conducted to investigate the effect of chlorinated water on storage quality and microbial reduction of tah tasai Chinese cabbage young leaf vegetable (microgreen). Fresh young leaves were washed in cold (5℃) and warm (25℃) chlorinated water with 0, 50 or 100 ㎎ㆍℓ?¹ free chlorine for 90 sec. Samples were then packaged in polypropylene (PP) film bag and stored for 8 days at 15℃. Changes in weight loss, color, SPAD value, external appearance, and aerobic plate count (APC) were evaluated. Chlorinated water treatment at 5℃ had a more beneficial effect on visual quality, weight loss, SPAD value change than 25℃ chlorinated water treatment. No significant difference was found in APC on the surface of tah tasai Chinese cabbage microgreen after 3-day storage period. Chlorinated water either at 5℃ or 25℃ with 50-100 ㎎ㆍℓ?¹ free chlorine significantly reduced APC during the initial period of storage (up to 2 days). The results indicated that chlorinated water only affected microbial reduction until tah tasai Chinese cabbage microgreen maintained its initial quality.

Microbial Differentiation on Chemical Properties of Paddy Soils in Reclaimed Tidal Lands at Western-coast Area of Korea

Mi-Na Park,Kwang-Min Yang,Jin-Hee Ryu,Tongmin Sa,Joon-Ho Choi 한국토양비료학회 2016 한국토양비료학회지 Vol.49 No.4

The scientific information on the microbial differentiation according to the changes in chemical properties of paddy soil in reclaimed tidal lands is not enough to understand the reclamation processes. The changes in microflora based on the chemical properties of paddy soils at the same sites of reclaimed tidal lands (21 samples from Nampo, Ewon, Sukmoon and Shihwa sites) were investigated in 2013 and 2015. In general, organic matter in paddy soils increased whereas pH decreased with the reclamation time. The electrical conductivities (EC) of soil samples were closely related to the exchangeable Na+. With an increases in EC of paddy soils from 0.39 to 48.9 dS m-1, the ratios (%) of halotolerant and halophilic bacteria to mesophilic bacteria proportionally increased from 0.2% to 102,000%. The population of halotolerant and halophilic bacteria in total microflora was also differentiated with the changes in EC of the same sites from reclaimed tidal soils within 2 years. The population of mesophilic bacteria decreased with an increase in EC above 5 dS m-1. The microflora including halotolerant and halophilic bacteria could be a candidate as a biological parameter in evaluating the reclamation processes in addition to the chemical index of EC.