Complete genome sequences of Lactococcus lactis JNU 534, a potential food and feed preservative

류상돈,Kiyeop Kim,Dae-Yeon Cho,Young Hoon Kim,Sejong OH 한국축산학회 2022 한국축산학회지 Vol.64 No.3

A new bacteriocin-producing lactic acid bacteria isolated from kimchi was identified as Lactococcus lactis JNU 534, presenting preservative properties for foods of animal origin. In this study, we present the complete genome sequence of the bacterial strain JNU 534. The final complete genome assembly consists of one circular chromosome (2,443,687 bp [base pair]) with an overall GC (guanine-cytosine) content of 35.2%, one circular plasmid sequence (46,387 bp) with a GC content of 34.5%, and one circular contig sequence (7,666 bp) with a GC content of 36.2%.

적콜라비 새싹채소 종자에서 분리한 Escherichia coli strain RC-4-D의 생장예측모델

최수연,류상돈,박병용,김세리,김현주,이승돈,김원일 한국식품저장유통학회 2017 한국식품저장유통학회지 Vol. No.

This study was conducted to develop a predictive model for the growth of Escherichia coli strain RC-4-D isolated from red kohlrabi sprout seeds. We collected E. coli kinetic growth data during red kohlrabi seed sprouting under isothermal conditions (10, 15, 20, 25, and 30℃). Baranyi model was used as a primary order model for growth data. The maximum growth rate (μmax) and lag-phase duration (LPD) for each temperature (except for 10℃ LPD) were determined. Three kinds of secondary models (suboptimal Ratkowsky square-root, Huang model, and Arrhenius-type model) were compared to elucidate the influence of temperature on E. coli growth rate. The model performance measures for three secondary models showed that the suboptimal Huang square-root model was more suitable in the accuracy (1.223) and the suboptimal Ratkowsky square-root model was less in the bias (0.999), respectively. Among three secondary order model used in this study, the suboptimal Ratkowsky square-root model showed best fit for the secondary model for describing the effect of temperature. This model can be utilized to predict E. coli behavior in red kohlrabi sprout production and to conduct microbial risk assessments.

Population changes and growth modeling of Salmonella enterica during alfalfa seed germination and early sprout development

김원일,류상돈,김세리,김현주,이승돈,김진우 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.6

This study examined the effects of alfalfa seed germination on growth of Salmonella enterica. We investigated the population changes of S. enterica during early sprout development. We found that the population density of S. enterica, which was inoculated on alfalfa seeds was increased during sprout development under all experimental temperatures, whereas a significant reduction was observed when S. enterica was inoculated on fully germinated sprouts. To establish a model for predicting S. enterica growth during alfalfa sprout development, the kinetic growth data under isothermal conditions were collected and evaluated based on Baranyi model as a primary model for growth data. To elucidate the influence of temperature on S. enterica growth rates, three secondary models were compared and found that the Arrhenius-type model was more suitable than others. We believe that our model can be utilized to predict S. enterica behavior in alfalfa sprout and to conduct microbial risk assessment

적콜라비 새싹채소 종자에서 분리한 Escherichia coli strain RC-4-D의 생장예측모델

최수연,류상돈,박병용,김세리,김현주,이승돈,김원일,Choi, Soo Yeon,Ryu, Sang Don,Park, Byeong-Yong,Kim, Se-Ri,Kim, Hyun-Ju,Lee, Seungdon,Kim, Won-Il 한국식품저장유통학회 2017 한국식품저장유통학회지 Vol.24 No.6

본 연구는 시중 유통되고 있는 새싹채소 재배용 적콜라비 종자에서 분리한 E. coli strain RC-4-D의 생장예측모델을 개발하기 위해 수행되었다. 각 온도조건(10, 15, 20, 25, $30^{\circ}C$) 별로 적콜라비 중 E. coli strain RC-4-D 밀도 변화를 조사하였고 Baranyi model을 1차 생장예측모델로 이용하였고 각 온도별로 최대생장률(${\mu}max$)과 $10^{\circ}C$를 제외한 유도기(LPD) 값을 도출하였다. E. coli strain RC-4-D의 최대생장률에 대한 2차 생장예측모델로써 suboptimal Ratkowsky square-root, suboptimal Huang square-root, suboptimal Arrhenius-type 세 종류의 모델을 비교하였다. 모델 적합성 검정 결과, suboptimal Huang square-root 모델이 정확도가 가장 높고 suboptimal Ratkowsky square-root 모델이 편차가 가장 적은 것으로 나타났다. 종합적으로, RMSE가 0.100, $A_f$가 1.255, $B_f$가 0.999인 suboptimal Ratkowsky square-root 모델이 온도의 영향을 설명하는 가장 적합한 2차 생장예측 모델인 것으로 나타났다. 본 연구에서 개발한 모델은 적콜라비 새싹채소 생산에 있어서 E. coli의 생장을 예측하고 미생물 위해성평가를 수행하는데 활용될 것으로 기대된다. This study was conducted to develop a predictive model for the growth of Escherichia coli strain RC-4-D isolated from red kohlrabi sprout seeds. We collected E. coli kinetic growth data during red kohlrabi seed sprouting under isothermal conditions (10, 15, 20, 25, and $30^{\circ}C$). Baranyi model was used as a primary order model for growth data. The maximum growth rate (${\mu}max$) and lag-phase duration (LPD) for each temperature (except for $10^{\circ}C$ LPD) were determined. Three kinds of secondary models (suboptimal Ratkowsky square-root, Huang model, and Arrhenius-type model) were compared to elucidate the influence of temperature on E. coli growth rate. The model performance measures for three secondary models showed that the suboptimal Huang square-root model was more suitable in the accuracy (1.223) and the suboptimal Ratkowsky square-root model was less in the bias (0.999), respectively. Among three secondary order model used in this study, the suboptimal Ratkowsky square-root model showed best fit for the secondary model for describing the effect of temperature. This model can be utilized to predict E. coli behavior in red kohlrabi sprout production and to conduct microbial risk assessments.

국내 생산단계 농산물의 미생물학적 안전성 조사

김원일,류재기,곽민규,조아라,류상돈,김세리,류송희,김황용 한국식품위생안전성학회 2017 한국식품위생안전성학회지 Vol.32 No.1

Foodborne disease outbreaks associated with produces have been increasing in occurrence worldwide. This study investigated microbial contamination levels on thirteen kinds of agricultural products from farms stage to evaluate potential hazards associated with foodborne illness. A total of 1,820 samples were collected in major cultivating area from 2013 through 2015, and analyzed to enumerate aerobic bacterial counts, coliforms/E. coli, Bacillus cereus and Staphylococcus aureus. In addition, the prevalence study for four kinds of microorganisms (Escherichia coli, E. coli O157:H7, Salmonella spp. and Listeria monocytogenes) was performed on each sample. Aerobic bacterial counts ranged from 0.01 to 7.18 log CFU/g, with the highest bacterial cell counts recorded for watermelon. Coliforms were detected in 651 samples (35.8%) with a minimum of 0.01 log CFU/g and a maximum of more than 5 log CFU/g. B. cereus was detected in 169 samples (9.3%) ranging from < 0.01 to 2.48 log CFU/g among total samples analyzed. S. aureus was detected in 14 samples (0.7%) with a minimum of 0.01 log CFU/g and a maximum of 1.69 log CFU/g. E. coli was detected in 101 samples (5.5%) among 1,820 samples. E. coli O157:H7, Salmonella spp. and L.monocytogenes were not detected in any of the samples. The microbial contamination levels of several agricultural products determined in this study may be used as the fundamental data for microbiological risk assessment (MRA).

콤부차 제품화를 위한 발효 특성 평가 및 기능성 평가

이정은,조정훈,김정헌,최혜진,이다슬,김종남,김영훈,류상돈 한국식품영양과학회 2022 한국식품영양과학회지 Vol.51 No.8

콤부차는 녹차나 홍차를 스코비(SCOBY)와 함께 발효시켜 만든 음료이며, 높은 항산화 활성, 소화율, 피부미용 능력, 비만 예방 효과를 가지고 있는 것으로 잘 알려져 있다. 본 연구에서는 기본적으로 설탕을 당원으로 발효한 콤부차에 2차 발효를 위한 5가지 2차 발효 첨가물(블루베리, 석류, 자몽, 건조 인삼, 오미자)을 첨가하여 실험을 진행하였다. 먼저 스코비에 존재하는 미생물들을 확인하고 여러 종류의 유리당, 유기산 및 에탄올의 농도를 측정했다. 또한, DPPH assay를 통해 항산화 활성을 측정하였고, RAW 264.7 세포를 이용한 NO assay를 통해 항염증 활성을 측정하였다. 스코비 미생물 동정 결과 초산균에 속하는 Acetobacter senegalensis와 Acetobacter tropicalis가 발견되었으며, Dekkera bruxellensis, Schizosaccharomyces pombe, Bruxellensis spp. 같은 효모들도 존재함을 확인하였다. 1차 발효 후 콤부차의 발효 특성을 분석한 결과 sucrose는 감소하였고 acetic acid는 증가하는 것으로 나타났으며, 2차 발효 시 2차 발효 첨가물에 따른 콤부차의 발효 특성 변화도 확인하였다. DPPH 분석 결과, 1차 발효 콤부차와 건삼 콤부차가 가장 높은 항산화 활성을 보였고 NO 분석 결과에서는 자몽과 인삼을 추가하여 발효한 콤부차에서 뛰어난 항염증 활성을 보였다. 따라서 본 연구를 통해 일반적인 콤부차의 발효 특성을 비롯하여 다양한 2차 발효 첨가물을 첨가한 2차 발효 콤부차의 발효 특성과 항산화 및 항염 효과 결과를 확인하였으며, 앞으로 콤부차의 건강 기능성과 관련된 연구에 도움이 될 것으로 사료된다.

Short Communication: Molecular characterization and functionality of rumen-derived extracellular vesicles using a Caenorhabditis elegans animal model

Hye Jin Choi,Daye Mun,류상돈,Min-Jin Kwak,Bum-Keun Kim,Dong-Jun Park,오상남,김영훈 한국축산학회 2023 한국축산학회지 Vol.65 No.3

The rumen fluids contain a wide range of bacteria, protozoa, fungi, and viruses. The various ruminal microorganisms in the rumen provide nutrients by fermenting the forage they eat. During metabolic processes, microorganisms present in the rumen release diverse vesicles during the fermentation process. Therefore, in this study, we confirmed the function of rumen extracellular vesicles (EVs) and their interaction with the host. We confirmed the structure of the rumen EVs by transmission electron microscope (TEM) and the size of the particles using nanoparticle tracking analysis (NTA). Rumen EVs range in size from 100 nm to 400 nm and are composed of microvesicles, microparticles, and ectosomes. Using the Caenorhabditis elegans smart animal model, we verified the interaction between the host and rumen EVs. Exposure of C. elegans to rumen EVs did not significantly enhance longevity, whereas exposure to the pathogenic bacteria Escherichia coli O157:H7 and Staphylococcus aureus significantly increased lifespan. Furthermore, transcriptome analysis showed gene expression alterations in C. elegans exposed to rumen EVs, with significant changes in the metabolic pathway, fatty acid degradation, and biosynthesis of cofactors. Our study describes the effect of rumen EV interactions with the host and provides novel insights for discovering biotherapeutic agents in the animal industry.

균주 선별 플랫폼에 따른 우수 목재 부후균의 염료 탈색 능력

이환휘 ( Aslan Hwanhwi Lee ),문기라 ( Kira Moon ),이나경 ( Nakyeong Lee ),류상돈 ( Sangdon Ryu ),송혜선 ( Hye Seon Song ),이진아 ( Jina Lee ),송승희 ( Seunghui Song ),김윤지 ( Yun Ji Kim ),이성문 ( Sung Moon Lee ),천세원 ( Se Won 한국목재공학회 2024 한국목재공학회 학술발표논문집 Vol.2024 No.1