Bioconversion of Ginsenosides from Red Ginseng Extract Using Candida allociferrii JNO301 Isolated from Meju

( Sulhee Lee ),( Yong Hun Lee ),( Jung Min Park ),( Dong Hoon Bai ),( Jae Kweon Jang ),( Young Seo Park ) 한국균학회 2014 Mycobiology Vol.42 No.4

Red ginseng (Panax ginseng), a Korean traditional medicinal plant, contains a variety of ginsenosides as major functional components. It is necessary to remove sugar moieties from the major ginsenosides, which have a lower absorption rate into the intestine, to obtain the aglycone form. To screen for microorganisms showing bioconversion activity for ginsenosides from red ginseng, 50 yeast strains were isolated from Korean traditional meju (a starter culture made with soybean and wheat flour for the fermentation of soybean paste). Twenty strains in which a black zone formed around the colony on esculin-yeast malt agar plates were screened first, and among them 5 strains having high β-glucosidase activity on p-nitrophenyl-β-D-glucopyranoside as a substrate were then selected. Strain JNO301 was finally chosen as a bioconverting strain in this study on the basis of its high bioconversion activity for red ginseng extract as determined by thin-layer chromatography (TLC) analysis. The selected bioconversion strain was identified as Candida allociferrii JNO301 based on the nucleotide sequence analysis of the 18S rRNA gene. The optimum temperature and pH for the cell growth were 20~30℃ and pH 5~8, respectively. TLC analysis confirmed that C. allociferrii JNO301 converted ginsenoside Rb1 into Rd and then into F2, Rb2 into compound O, Rc into compound Mc1, and Rf into Rh1. Quantitative analysis using high-performance liquid chromatography showed that bioconversion of red ginseng extract resulted in an increase of 2.73, 3.32, 33.87, 16, and 5.48 fold in the concentration of Rd, F2, compound O, compound Mc1, and Rh1, respectively.

OVERVIEW OF KSTAR INTEGRATED CONTROL SYSTEM

MIKYUNG PARK,KUKHEE KIM,TAEGU LEE,MYUNGKYU KIM,JAESIC HONG,SULHEE BAEK,SANG-IL LEE,JIN-SEOP PARK,YONG CHU,YOUNG-OK KIM,SANG-HEE HAHN,YEONG-KOOK OH,JOO-SHIK BAK 한국원자력학회 2008 Nuclear Engineering and Technology Vol.40 No.6

After more than 10 years construction, KSTAR (Korea Superconducting Tokamak Advanced Research) had finally completed its assembly in June 2007, and then achieved the goal of first-plasma in July 2008 through the four month’s commissioning. KSTAR was constructed with fully superconducting magnets with material of Nb3Sn and NbTi, and their operation temperatures are maintained below 4.5K by the help of Helium Refrigerator System. During the first-plasma operation, plasmas of maximum current of 133kA and maximum pulse width of 865ms were obtained. The KSTAR Integrated Control System (KICS) has successfully fulfilled its missions of surveillance, device operation, machine protection interlock, and data acquisition and management. These and more were all KSTAR commissioning requirements. For reliable and safe operation of KSTAR, 17 local control systems were developed. Those systems must be integrated into the logically single control system, and operate regardless of their platforms and location installed. In order to meet these requirements, KICS was developed as a network-based distributed system and adopted a new framework, named as EPICS (Experimental Physics and Industrial Control System). Also, KICS has some features in KSTAR operation. It performs not only 24 hour continuous plant operation, but the shot-based real-time feedback control by exchanging the initiatives of operation between a central controller and a plasma control system in accordance with the operation sequence. For the diagnosis and analysis of plasma, 11 types of diagnostic system were implemented in KSTAR, and the acquired data from them were archived using MDSplus (Model Driven System), which is widely used in data management of fusion control systems. This paper will cover the design and implementation of the KSTAR integrated control system and the data management and visualization systems. Commissioning results will be introduced in brief.

Isolation and Characterization of Microbial Strains with Hydrolytic Enzyme Profile from Clay Minerals

( Sulhee Lee ),( Eui-sang Cho ),( Young-do Nam ),( So-lim Park ),( Seong-il Lim ),( Dong-ho Seo ),( Jae-hwan Kim ),( Myung-ji Seo ) 한국미생물 · 생명공학회 2020 한국미생물·생명공학회지 Vol.48 No.1

A total of 262 bacterial strains were isolated from clay minerals, bentonite and zeolite, in Gyeongsangbukdo, Republic of Korea, and their hydrolytic enzyme activities were analyzed. Most of the isolated strains belonged to Micrococcales and Bacillales order. Of strains, 96 strains produced α-amylase activity, 42 strains showed cellulase activity, 111 strains had pectinase activity, and 70 strains showed protease activity. Among them, 177 isolates exhibited one or more of the hydrolytic enzyme activities and in particular Bacillus cereus MBLB1321, B. albus MBLB1326 and KIGAM017, B. mobilis MBLB1328, MBLB1329 and MBLB1330 showed all of the enzyme activities. These results demonstrate the diversity of functional Bacillus species in clay minerals as vital sources for the discovery of industrially valuable hydrolytic enzymes, which have a great commercial prospect in various bio-industrial applications.

Amelioration of sarcopenia in aged mice through intake of Weissella cibaria isolated from kimchi

Sulhee Lee,Boeun Kim,Young Seo Jang,Sang-Pil Choi,Namhee Kim,Min-Sung Kwon,Young Joon Oh,Sang Min Park,Ji Ye Mok,Hak-Jong Choi 한국산업식품공학회 2023 학술대회 및 심포지엄 Vol.2023 No.11

Quantitative measurement of peri-implant bone defects using optical coherence tomography

Sulhee Kim,Se-Ryong Kang,Hee-Jung Park,Bome Kim,Tae-Il Kim,Won-Jin Yi 대한치주과학회 2018 Journal of Periodontal & Implant Science Vol.48 No.2

Purpose: The purpose of this study was to visualize and identify peri-implant bone defects in optical coherence tomography (OCT) images and to obtain quantitative measurements of the defect depth. Methods: Dehiscence defects were intentionally formed in porcine mandibles and implants were simultaneously placed without flap elevation. Only the threads of the fixture could be seen at the bone defect site in the OCT images, so the depth of the peri-implant bone defect could be measured through the length of the visible threads. To analyze the reliability of the OCT measurements, the flaps were elevated and the depth of the dehiscence defects was measured with a digital caliper. Results: The average defect depth measured by a digital caliper was 4.88±1.28 mm, and the corresponding OCT measurement was 5.11±1.33 mm. Very thin bone areas that were sufficiently transparent in the coronal portion were penetrated by the optical beam in OCT imaging and regarded as bone loss. The intraclass correlation coefficient between the 2 methods was high, with a 95% confidence interval (CI) close to 1. In the Bland-Altman analysis, most measured values were within the threshold of the 95% CI, suggesting close agreement of the OCT measurements with the caliper measurements. Conclusions: OCT images can be used to visualize the peri-implant bone level and to identify bone defects. The potential of quantitative non-invasive measurements of the amount of bone loss was also confirmed.

Screening of Glucansucrase-Producing Lactic Acid Bacteria

Sulhee Lee,Young-Seo Park 한국산업식품공학회 2016 학술대회 및 심포지엄 Vol.2016 No.10

Glucansucrases are members of GH70 family of glycoside hydrolases and mainly produced by lactic acid bacteria such as Leuconostoc, Lactobacillus, and Weisella species. Glucansucrases use sucrose as a substrate to synthesize glucans as well as to produce oligosaccharides by transferring glucose moiety from sucrose onto acceptor carbohydrate molecules. It is known that some oligosaccharides produced by the reaction of glucansucrase show functional properties such as prebiotics and immunostimulatory activities. In this study, lactic acid bacteria which produce glucansucrase were screened from a variety of fermented foods, vegetables, and fruits collected from various area of Korea. Among 149 lactic acid bacteria strains which were isolated using BCP agar plates, 8 strains were selected which showed high glucansucrase activities. By nucleotide sequence analysis of 16S rRNA gene, strain no. 26-4 and 109-4 were identified as Leuconostoc mesenteroides, strain no. 95-4 strain was L. lactis, strain no. 92-4 and 112-1 were Weissella kimchii, strain no. 94-1 and 95-1 strains were W. confusa, and strain no. 113 was W. cibaria. When the oligosaccharides produced by the reaction of glucansucrase were analyzed using Bio-LC after these lactic acid bacteria were cultured into sucrose-containing media, the chromatograms of all bacterial showed unidentified peaks which implied the newly synthesized oligosaccharides

Leuconostoc lactis CCK940의 Glucansucrase 활성에 의한 올리고당 생산 최적화

이설희 ( Sulhee Lee ),박영서 ( Young-seo Park ) 한국산업식품공학회 2017 산업 식품공학 Vol.21 No.4

국내 재래시장에서 수집한 발효식품 등에서 우수한 glucansucrase 활성을 나타내는 유산균주를 분리한 후 이 균주를 이용한 올리고당 생성의 최적 조건을 조사하였다. 배추김치로부터 분리된 유산균주 CCK940은 glucansucrase 활성이 918.2 mU/mL로 가장 높아 본 올리고당 생산을 위한 균주로 선정하였고, Leu. lactis CCK940로 동정 및 명명되었다. 선정된 Leu. lactis CCK940는 배지의 pH를 6.0으로 조정하고 공여체인 sucrose와 수용체인 maltose의 초기 농도를 각각 5% (w/v)와 10% (w/v)로 첨가한 후 배양 4시간과 8시간째에 sucrose를 5% (w/v) 첨가하는 것이 최적인 것으로 확인되었다. 최적 조건에 12시간 배양 시 Leu. lactis CCK940는 중합도가 2-4인 올리고당을 최소 4종류 생성하였다. 본 균주는 수용체 분자로서 fructose와 melibiose를 사용할 수 없었다. Glucansucrase is an enzyme classified as a glycoside hydrolase (GH) 70 family, which catalyzes the synthesis of glucooligosaccharides with a low molecular weight using sucrose as a donor of D-glucopyranose and maltose as a carbohydrate acceptor. In this study, glucansucrase-producing lactic acid bacteria strain was isolated from the fermented foods collected in traditional markets, and the optimum conditions for the oligosaccharide production were investigated. The strain CCK940 isolated from Chinese cabbage kimchi was selected as an oligosaccharide-producing strain due to its high glucansucrase activity, with 918.2 mU/mL, and identified as Leuconostoc lactis. The optimum conditions for the production of oligosaccharides using Leu. lactis CCK940 were to adjust the initial pH to 6.0, add 5% (w/v) sucrose and 10% (w/v) maltose as a donor and acceptor molecules, respectively, and feed 5% (w/v) sucrose at 4 and 8 h of cultivation. When Leu. lactis CCK940 was cultured for 12 h at optimum conditions, at least four oligosaccharides with a polymerization degree of 2-4 were produced.

Protease를 생산하는 Lactobacillus paracasei의 분리와 이를 이용한 두유 발효 최적화

이설희(Sulhee Lee),장동훈(Dong-Hun Jang),최혁준(Hyuk Jun Choi),박영서(Young-Seo Park) 한국식품과학회 2013 한국식품과학회지 Vol.45 No.5

본 연구에서는 김치나 젓갈 등 각종 발효식품으로부터 단백질 가수분해 활성이 있는 총 108주의 분리된 유산균 중 일정 수준 이상의 protease 활성을 지니는 29주를 선정하였다. 그 중 두유 단백질 분해능이 가장 높은 균주 MK1을 본 연구의 발효균주로 최종 선정하였고, 생리학적 특성 및 16S rRNA 유전자 염기서열 등과 같은 분자유전학적 분석을 통해 Lactobacillus paracasei MK1로 동정 및 명명하였다. L. paracasei MK1을 이용하여 두유의 최적 발효산물을 제조하기 위하여 pH, 적정 산도, 생균수 및 단백질 분해 양상에 따른 최적화 연구를 실시하였다. L. paracasei MK1의 종배양액을 멸균한 두유에 2%(v/v)접종하여 발효시켰을 경우, 발효의 최적온도는 30℃이었으며, 이 때의 적정산도와 pH는 발효 초기 0.15%와 pH 7.31에서 24시간 발효 후 0.98%과 pH 4.56으로 변화하였다. 생균수는 초기 6.94 log CFU/mL에서 발효후 9.03 ? CFU/mL로 증가하였다. 두유의 최적 희석배수는 50%로서 적정산도는 배양 24시간 후 0.08%에서 0.45%로 증가하였다. 최적 초기 pH는 6.0이었으며 탄소원으로 2%(w/v) glucose를 50%로 희석한 두유에 첨가하고, 30℃에서 두유 발효를 실시하였을 때 가장 적합한 발효 경향을 나타내었다. Our aim was to ferment soymilk using lactic acid bacteria that showed protease activity and to optimize the condition for fermentation. In total, 108 strains of protease-producing lactic acid bacteria were isolated from various fermented foods such as kimchi and jeotgal, and among them, 29 strains displaying the highest protease activity were selected for further study. From these 29 strains, strain MK1, whose protease activity was 126 mU/mL·min, was selected as the optimal fermentation strain owing to its high ability to digest soymilk protein. It was henceforth labeled as Lactobacillus paracasei MK1. The optimum conditions for the fermentation of soymilk by using L. paracasei MK1 were determined to be as follows: 30 h of fermentation time at a temperature of 30℃, and at a pH of 6.0 in the initial growth medium.

Comparative Analysis of Growth-Phase-Dependent Gene Ex-pression in Virulent and Avirulent Streptococcus pneumoniae Using a High-Density DNA Microarray

고관수,Sulhee Park,오원섭,Ji-Yoeun Suh,TaeJeong Oh,Sungwhan Ahn,천종식,송재훈 한국분자세포생물학회 2006 Molecules and cells Vol.21 No.1

Pediococcus pentosaceus의 Multilocus Sequence Typing 분석에서 신규 Sequence Type의 확인

이설희 ( Sulhee Lee ),박영서 ( Young Seo Park ) 한국산업식품공학회 2015 산업 식품공학 Vol.19 No.4

The genus Pediococcus belongs to the lactic acid bacteria and includes 15 species which are used in the food industry as both starter and probiotic cultures. The importance of Pediococcus spp. is due to their use as starter cultures in fermented meat as well as to their presence as the natural microbiota in vegetables. The availability of P. pentosaceus in the food industry increases the need for reliable molecular techniques for strain identification. To date, the reliable molecular methods for definite identification at strain level of microorganisms used in food industry has not been developed. Molecular identification based on suitable marker genes could be a promising alternative to conventional molecular typing methods such as ribotyping. In this study, the applicability of seven housekeeping genes gyrB, pyc, pgm, leuS, glnA, and dalR in combination with the pgi gene in multilocus sequence typing of P. pentosaceus was assessed. Sequencing and comparative analysis of sequence data were performed on 6 strains isolated from various vegetables. In addition to 17 sequence types, two new sequence types were identified and these fortified sequence types and seven marker genes allowed for a clear differentiation of the strains analyzed, indicating their applicability in molecular typing.