Niabella ginsenosidivorans sp. nov., isolated from compost

이권정,임완택,김동운,Qing Mei Liu,김수기 한국미생물학회 2015 The journal of microbiology Vol.53 No.11

A Gram-reaction negative, strictly aerobic, non-motile, orange colored, and rod-shaped bacterium (designated BS26T) isolated from compost, was characterized by a polyphasic approach to clarify its taxonomic position. Strain BS26T was observed to grow optimally at 25–30°C and at pH 7.0 on R2A and nutrient media. Strain BS26T showed β-glucosidase activity that was responsible for its ability to transform ginsenoside Rb1 (one of the active components of ginseng) to ginsenoside compound-K (C-K). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain BS26T belongs to the genus Niabella of family Chitinophagaceae and was most closely related to Niabella soli DSM 19437T (94.5% similarity), N. yanshanensis CCBAU 05354T (94.3%), and N. aurantiaca DSM 17617T (93.8%). The G+C content of genomic DNA was 47.3 mol%. Chemotaxonomic data [predominant isoprenoid quinone-MK-7, major fatty acids–iso-C15:0, iso-C15:1 G, iso-C17:0 3-OH, and summed feature 3 (comprising C16:1 ω7c and/or C16:1 ω6c)] supported the affiliation of strain BS26T to the genus Niabella. However, strain BS26T could be differentiated genotypically and phenotypically from the recognized species of the genus Niabella. The novel isolate therefore represents a novel species, for which the name Niabella ginsenosidivorans sp. nov. is proposed, with the type strain BS26T (=KACC 16620T =JCM 18199T).

사료자원에 서식하는 세균의 소화효소활성, 항생제내성 및 병원성에 관한 특성

이권정 ( Kwon Jung Yi ),조상섭 ( Sang Seop Cho ),김수기 ( Soo-ki Kim ) 한국가축위생학회 2017 韓國家畜衛生學會誌 Vol.40 No.2

Among different types of spoilage, microbial contamination can cause feed decomposition, which results in decreases in feed intake and productivity, infection, and breeding disorder. During the storage time, various microbes have a chance to inoculate with depreciation of feed and to infect the animals. We investigated bacteria that inhabit diverse feed ingredients and complete feed which have been stored for a few months. We isolated and identified 30 genera and 62 species of bacteria. Among these 62 species, 21 species were of non-pathogenic bacteria, 18 species were of pathogenic bacteria, 9 species were of opportunistic pathogens, and 14 species were of unknown bacteria. Pantoea allii and 24 species showed proteolytic enzyme activity. We also confirmed that 6 species including Pseudomonas psychrotolerans showed α-amylase activity, and 29 species including Burkholderia vietnamiensis showed cellulase activity. Microbacterium testaceum and 3 species showed resistance to Ampicillin, Kanamycin, Streptomycin, Gentamicin, Carbenicillin, and Erythromycin (50 μg/mL). Using mealworm larvae (Tenebrio molitor L.) as a model for pathogenicity, we confirmed that 8 species including Staphylococcus xylosus had pathogenicity for mealworm larvae. Especially, Enterobacter hormaechei, Staphylococcus xylosus, and Staphylococcus hominis were reported as being pathogenic for humans. This research suggests that hygienic management of animal feed is essential because beneficial and harmful bacteria can inhabit animal feed differently during storage and distribution.

배합사료의 부패 동안 발생하는 미생물학적 및 영양학적 변화

이권정(Kwonjung Yi),연제성(Jae-Sung Yeon),김주현(Juhyeon Kim),김삼철(Sam Churl Kim),문형인(Hyung-In Moon),전체옥(Che Ok Jeon),이상석(Sang Suk Lee),김동운(Dong-Woon Kim),김수기(Soo-Ki Kim) 한국생명과학회 2015 생명과학회지 Vol.25 No.10

가축의 배합사료는 가축의 성장을 유지하기 위한 충분한 영양소를 함유하고 있어 적절한 온도와 습도하에서 부패되기 쉽다. 착유우 사료를 여름철 고온 다습한 환경 조건인 수분 33%, 온도 30℃에서 15일 동안 부패시키면서 일어나는 미생물 및 화학적 변화를 조사하였다. pH는 최초 6.29에서 4.66으로, 수분활성은 0.99에서 0.95으로 각각 감소하였다. 세균은 6.2×10<SUP>6</SUP>~1.6×10<SUP>7 </SUP>CFU/g에서 5일째에 최대 2.1×10<SUP>9</SUP> CFU/g까지 증가하였으며 이후 108 CFU/g 수준을 유지하였다. 곰팡이는 약 10<SUP>3</SUP>에서 8.0×10<SUP>4</SUP> CFU/g으로 증가하였다. 세균은 Acinetobacter oleivorans, Pediococcus acidilactici, Acinetobacter oleivorans, Weissella cibaria 및 Methylobacterium komagatae이 성장하였고, 곰팡이는 Fusarium속과 Mucor속이 분리되었다. 10일까지는 수분 함량은 증가하였고(p<0.01), 조단백질 함량은 큰 변화가 없었으나 조지방은 약 6.0%에서 5.5%로 감소하였다(p<0.01). 조섬유와 조회분은 각각 2.0~3.0%, 4.5~4.8%의 범위에서 변화되었으나 유의적인 차이는 없었다. 총에너지는 4,400 kcal/kg로 거의 변화가 없었다. 사료가 부패되면서 젖산과 프로피온산은 증가하였고 아세트산은 검출되지 않았다(p<0.01). 제랄레논은 59.2 μg/kg에서 623.8 μg/kg으로 약 10.5배가 증가하였다. 결론적으로 사료부패가 일어나는 동안은 pH 감소, 생균수의 증가 및 다양한 화학적 변화가 관찰되었다. Commercial complete feeds contain enough nutrients to support animal growth and it is easy to be spoiled under proper temperature and humid conditions. The aim of this study was to investigate microbiological and chemical changes on complete feed for milking cow under open-air exposure with moisture 33% at 30℃ during 15 days. pH decreased 6.29 to 4.66 and water activity decreased gradually 0.99 to 0.95. Bacteria increased 6.2×10<SUP>6</SUP>~1.6×10<SUP>7</SUP> to 2.1×10<SUP>9</SUP> CFU/g at 5 days and showed 10<SUP>8</SUP> CFU/ g until 15 days. Fungi increased 10<SUP>3</SUP> CFU/g to 8.0×10<SUP>4</SUP> CFU/g. During the processing of spoilage, bacteria such as Acinetobacter oleivorans, Pediococcus acidilactici, Acinetobacter oleivorans, Weissella cibaria, and Methylobacterium komagatae were identified and fungi such as Fusarium sp. and Mucor sp. were also identified. Moisture content increased until 10 days (p<0.01). Crude protein was not changed so much whereas crude fat decreased 6.0% to 5.5% (p<0.01). Crude fiber and crude ash changed 2.0~ 3.0% and 4.5~ 4.8% levels with no significance, respectively. Gross energy was not almost changed at 4,400 kcal/g. During spoilage, lactate and propionate increased whereas acetate was not detected. Protease and lipase activities increased significantly during spoilage (p<0.01). Zearalenone content increased 59.2 μg/kg to 623.8 μg/kg, showing 10.5 times more production. During feed spoilage, pH decreased with microbial growth and various chemical changes were occurred.

세종과 대전지역 부동산시장의 상호 영향 관계 : 행정중심복합도시 건설 단계별

이권정(Lee, Kwon-Jung),정재호(Chung, Jae-Ho) 한국부동산정책학회 2017 不動産政策硏究 Vol.18 No.3

The purpose of this study is to examine what effects the construction of multifunctional administrative city located at Sejong-si had on peripheral real estate at each step of development and seek out its implications. To this end, it designed some study models by Sejong-si and each real estate market by using land value index, average housing and rental price of apartments in Sejong-si, Daejeon-si, Yuseong-gu, Daejeon, west districts of Daejeon from January, 2002 to April, 2017, as variables. The study models conducted empirical analyses on the effect relationship between the periphery of Sejong-si and the real estate market, in connection with main issues in the construction of multifunctional administrative city, by dividing data by each step (plan, construction starting and transference) on the criteria of construction starting time (7. 20. 2007) and launching of Sejong-si (7. 1. 2012). The ADF test of time series data’s stability verified instability of the original time series, so the first order differenced one was determined to be used and a proper time lag for each variable was set as the first order according to AIC and SC. In addition, the establishment long-run equilibrium was examined by Unit-root and Cointegration Test, and then VAR model was established. This study initially understand the long-run equilibrium between variables through VECM and the short run effect relationship around outcomes of models, as there are the cointegration in some models. In order to confirm effects of such variables, the Granger Causality Test was conducted and a related structure was examined. Finally, it analyzed directions and magnitude of influences, with impulse response function and variance decomposition. The findings from such an empirical analysis can be summarized: First, effects of land market in Sejong-si were differentiated by each area, depending on analysis time (step of development in Sejong-si). Second, spillover effects of land market in Sejong-si on peripheral land market, along with the construction of multifunctional administrative city occurred not immediately but after time lag. Third, housing and rental market of apartments together with land market in Sejong-si since the launching of the city has dominated fluctuation of price in such markets in each area. Finally, the influence of land market in Sejong-si since the launching of the city has been gradually dampened, while those of housing and rental markets in Sejong-si have been reinforced.

고온 조건에서 사료 내 생균제의 생존성 및 오염미생물의 생장 억제 효과

김겸헌,이권정,이아란,장인환,송인근,김동운,김수기,Kim, Gyeom-Heon,Yi, Kwon-Jung,Lee, Ah-Ran,Jang, In-Hwan,Song, In-Geun,Kim, Dong-Woon,Kim, Soo-Ki 한국미생물학회 2014 미생물학회지 Vol.50 No.4

여름철의 고온으로의 온도 상승에 따른 사료빈 내의 생균제 L. plantarum, S. cerevisiae 및 B. subtilis의 생존성을 실험실의 가상 조건에서 분석하였다. 상온인 $25^{\circ}C$에서 멸균 사료와 비멸균 사료에 단일 혹은 혼합 균주 첨가 시 pH 변화와 생균제들의 생장을 상호 비교하였다. pH는 멸균 사료와 비멸균 사료 모두에서 4일째에 가장 감소한 것은 같았으나 비멸균 사료에서는 2일째까지는 상승하는 변화의 양상을 보여주었다. 멸균 여부 혹은 혼합 여부와 관계없이 S. cerevisiae와 B. subtilis의 생균수는 일정하게 유지되었지만 L. plantarum의 경우에는 그 수가 모두 줄어드는 것을 확인할 수 있었다. 따라서 3종의 혼합 생균제는 상호 길항작용은 없는 것으로 나타났다. 멸균 및 비멸균 사료에 생균제를 첨가한 후 $60^{\circ}C$의 고온 환경에서 사료의 pH 와 단일접종 생균제의 생존성을 조사하였다. 멸균 및 비멸균 사료 사이에 뚜렷한 pH의 변화는 관찰되지 않았으며 B. subtilis의 pH가 가장 낮게 관찰되었다. 고온 하에서 L. plantarum과 S. cerevisiae 균주는 생존할 수 없었으며, 내열성을 가진 B. subtilis 균주는 생존하면서 사료에 자연적으로 생존하는 오염세균의 증식을 억제하였다. 또 B. subtilis를 접종한 비멸균 사료에서 2일째부터 오염 곰팡이가 관찰되지 않았다. 따라서 내열성이 강한 B. subtilis 균주를 사용하면, 여름철 사료빈 내에 병원성 세균과 곰팡이의 오염을 억제할 수 있는 것으로 나타났다. The aim of this study was to investigate the effect of high temperature on the viability of probiotic organisms (Bacillus subtilis, Lactobacillus plantarum, and Saccharomyces cerevisiae) mixed with animal feed under controlled conditions by simulating a farm feed bin in the summer. Following inoculation of probiotics into the feed, the pH and probiotic viability were monitored during an 8-day incubation at room temperature. Sterile and non-sterile feeds displayed different patterns of pH changes, with increased pH in non-sterile feed at 2 days, but a pattern of decreasing pH at 4 days. The viabilities of S. cerevisiae and B. subtilis after mono/co-inoculation were maintained without substantial changes during the incubation, whereas L. plantarum viability tended to decline. In both non-sterile and sterile feeds, the probiotics were maintained or grew without any antagonistic effects. Probiotic viability was also tested upon a shift to high temperature ($60^{\circ}C$). There was no distinct change in pH between sterile and non-sterile feeds after the temperature shift. L. plantarum and S. cerevisiae could not survive at the high temperature, whereas B. subtilis displayed normal growth, and it inhibited the growth of contaminant microbes. Fungal growth was not observed in non-sterile feed 2 days after supplementation with B. subtilis. Therefore, heat resistant B. subtilis could be safely used in feed bins to inhibit microbial contamination, even at high temperatures. The prevention of elevated temperature in feed bins is necessary for the utilization of L. plantarum and S. cerevisiae during the summer season.

착유우용 배합사료의 부패과정 중 발생하는 저분자 유기화합물의 분석

김용탁 ( Yong Tak Kim ),이권정 ( Kwon Jung Yi ),김겸헌 ( Gyeom-heon Kim ),김동운 ( Dong Woon Kim ),김수기 ( Soo Ki Kim ),문형인 ( Hyung-in Moon ) 한국가축위생학회 2016 韓國家畜衛生學會誌 Vol.39 No.3

In this study, we analyzed for the changes of low organic compounds during 4 weeks incubation though inoculation of harmful microorganisms on commercial feed. Two percent of overnight cultures of Exiguobacterium acetylicum, Acinetobacter calcoaceticus, Aspergillus flavus and Fusarium graminearum were inoculated in feed, respectively. After adjusting moisture level to 50% for the promotion of feed spoilage, pH was decreased to 4.58∼5.03 and microorganism was ranged to 6∼10 log₁₀CFU/g. The compounds were compare between aflatoxin G1 producing feeds and aflatoxin G1 non-producing feeds. Aflatoxins G1 were detected by the immunoaffinity column clean-up method with HPLC-FLD, and were confirmed in samples incoulated by Aspergillus flavus and Acinetobacter calcoaceticus. Koiganal II, cy-clohexanol and butadien-one were detected from samples (the non-sterilized inoculated feed) by Aspergillus flavus and Acinetobacter calcoaceticus. Respectively as aflatoxin G1 pre-detected substance, Koiganal II, cyclohexanol and butadien-one may be useful substance for the pre-detection of aflatoxin G1.

배합사료의 자연부패과정 중 발생하는 저분자 유기화합물의 동정 및 분석

유지민 ( Ji Min Yu ),김용탁 ( Yong Tak Kim ),이권정 ( Kwon Jung Yi ),김동운 ( Dong-woon Kim ),김수기 ( Soo-ki Kim ),문형인 ( Hyung In Moon ) 한국가축위생학회 2017 韓國家畜衛生學會誌 Vol.40 No.4

In this study, the changes of low molecular weight compounds during natural decay process for 4 weeks were analyzed. Natural corruptions were observed in the slate warehouse with summer humidity and temperature throughout the rainy season by using commercially available compound feeds. Koiganal was detected from 14 days of natural decay and corruption with chicken, pig, and Korean cattle feed. Ethyl palmitate, Ethyl pentadecanoate and, Methyl elaidatel were detected from chicken, pig, and Korean cattle feed. So, Koiganal can be useful for monitoring the degree of pollution of corruption of livestock feeds in advance.

Characteristics of Eggshell Powder as Carriers of Probiotics

Woo-Do Lee(이우도),Kai-Min Niu(우개민),Jeong-Min Lim(임정민),Kwon-Jung Yi(이권정),Bong-Joo Lee(이봉주),Kang-Woong Kim(김강웅),Kyoung-Duck Kim(김경덕),Sang-Woo Hur(허상우),Hyon-Sob Han(한현섭),Soo-Ki Kim(김수기) 한국생명과학회 2018 생명과학회지 Vol.28 No.1

계란 가공 부산물인 난각(ES: Eggshell)은 탄산칼슘 함량이 높아 사료에 첨가하여 칼슘원으로 이용되고 있다. 본 연구에서는 ES를 생균제의 부형제인 운반체로서 활용 가능성을 처음으로 시도하였다. L. plantarum을 대두박(SBM: Soybean meal), 난각조각(ESL: Eggshell powder with large particles), 난각미세분말(ESF: Eggshell powder with fine particles), 그리고 이들의 복합운반체인 SBM+ESL과 SBM+ESF에 생균제를 흡착시켜 그 부착상태를 주사전자현미경으로 확인하였다. 이 중 복합운반체인 SBM+ESF는 상온에서 4주 동안 pH 7~8을 유지하면서 L. plantarum의 가장 높은 생존율을 보였다. 본 연구에 사용한 모든 생균제들은 보존기간 동안 4℃에서는 높은 생존율을 보였다. 30℃에서는 유산균수는 크게 감소하였으나, B. licheniformis는 높은 생존율을 유지하였고 B. subtilis, B. amyloliquefaciens와 S. cerevisiae는 2 log10 (CFU/g)정도 감소하였다. 상기 연구결과는 사료의 칼슘원으로 이용되는 난각미세분말(ESF)을 대두박과 혼합하여 사용하면 B. licheniformis를 비롯한 일부 생균제의 생존성을 향상시켜 부형제(운반체)로도 사용할 수 있음을 밝혔다. Eggshell (ES) is a by-product of table eggs with high content of calcium carbonate which can be used as a calcium source in feed. In this study, we have first illuminated the potential application of ES as a novel carrier for probiotics. The carriers used in the study include a SBM (Soybean meal), ESL (Eggshell powder with large particles), ESF (Eggshell powder with fine particles), and the complex carriers (SBM+ESL, SBM+ESF). The structure of carriers absorbed by L. plantarum was confirmed by SEM image. Among these carriers, the complex carrier SBM+ESF showed the highest viability of L. plantarum with pH 7~8 during four weeks storage at room temperature. The SBM+ESF was further tested as a carrier for various probiotic strains at 4℃ or 30℃. All the probiotic strains showed high viability at 4℃ storage. However, a significant reduction of Lactobacillus cells was observed at 30℃ storage. B. lichenifomis maintained high viability whereas B. subtilis, B. amyloliquefaciens, and S. cerevisiae showed the reduction of 2 log10 (CFU/g). These results suggest that if the ESF as a calcium source in feed was mixed with SBM, it can be used as an effective complex carrier for improving the viability of some probiotics including B. licheniformis.

도계 후 원료육의 저장기간 동안 가슴육의 품질 특성

황용준(Yong-Joon Hwang),박도희(Do-Hee Park),윤성호(Sung-Ho Yoon),김동준(Dong-Joon Kim),이원복(Won-Bok Lee),연제성(Jae-Sung Yeon),이권정(Kwon-Jung Yi),김수기(Soo-Ki Kim) 한국가금학회 2015 韓國家禽學會誌 Vol.42 No.4

본 연구는 도계 후 원료육의 저장기간에 따른 품질 특성을 조사하여 가공업소에서 반입되는 원료육에 대하여 현행 등급판정기준인 ‘도계 후 2일 이내의 원료육’의 사용이 적합한지 혹은 어느 정도 연장이 가능한지 여부를 판단하기 위하여 처음으로 수행하였다. 당일 도계한 원료육부터 도계 후 4일 경과된 원료육까지 총 40개의 샘플을 3℃의 냉장고에 냉장보관하여 부분육으로 발골 후 가슴육에 대하여 품질 특성을 연구하였다. 도계 후 2일 경과된 원료육과 3일 경과된 원료육을 비교 분석한 결과, 신선도는 각각 6.9와 7.0, 육색은 60.22와 60.51, 총균수는 4.20과 4.31 log10CFU/g, 지방산패도는 0.056과 0.071 mg MDA/kg, 전단력은 1.43과 1.59 kg/㎠, 가열감량은 17.24와 15.66%의 결과를 보였다. 신선도, 육색, 총균수, 지방산패도, 전단력 및 가열감량 모두 본 연구에서 도계 후 2일 경과된 원료육과 3일 경과된 원료육 간에 통계적 유의적인 차이가 없었다. 도계 후 4일 경과된 원료육은 신선도, 총균수, 전단력, 가열감량의 실험에서 2∼3일 경과된 원료육과 통계적 유의적인 차이가 없었으나, 지방산패도는 0.088 mg MDA/kg으로 유의적으로 높은 값을 보였다(P<0.05). 따라서 본 실험의 결과는 도계 후 3일 이내의 원료육도 사용이 가능하다는 것을 시사하였다. 등급판정 시 원료육의 사용 가능 시점을 도계 후 현행 2일에서 3일로 하루 연장할 수 있다면 닭고기 가공 및 유통업체는 원료육 사용 혹은 유통의 폭이 보다 넓어질 것으로 기대된다. This study was first conducted to investigate the effect of post-mortem storage time of chicken meat on the quality of chicken breast, and to determine whether the current grading rule that is ‘using the chicken meat within 2 day post-mortem (PM)’ is appropriate or not at meat processing plants. Different methods such as freshness, lightness (L<SUP>*</SUP>), total number of microbes, 2-thiobarbituric acid reactive substances (TBARS), shear force and cooking loss were performed. Forty samples of different PM time (0∼4 day) of chicken meat were stored in the refrigerator (3℃). As a result of comparing the chicken meat of 2 day and 3 day PM, torrymeter value was 6.9 and 7.0, respectively. The other values are also as follows: lightness (L<SUP>*</SUP>) 60.22 and 60.51, total number of microbes 4.20 and 4.31 log10CFU/g, TBARS value 0.056 and 0.071 mg MDA/kg, shear force 1.43 and 1.59 kg/㎠, and cooking loss 17.24 and 15.66%, respectively. As a result, these two groups were not significantly different (P<0.05). TBARS value of the chicken meat of 4 day PM was 0.088 mg MDA/kg which is significantly higher compared to 2∼3 day PM (P<0.05). Thus, the result of the study suggests that using the chicken meat within 3 day PM is also possible. If the grading rule that is ‘using the chicken meat within 2 day post-mortem (PM)’ is changed to 3 day PM, it will allow processing plants and distributors to more flexibly use or distribute chicken meat.