Ultrasonic Degradation of Endocrine Disrupting Compounds in Seawater and Brackish Water

So Young Park,Jong Sung Park,Ha Yoon Lee,Ji Yong Heo,Yeo Min Yoon,Kyung Ho Choi,Nam Guk Her 대한환경공학회 2011 Environmental Engineering Research Vol.16 No.3

In this study, a series of experiments was conducted on the relative degradation of commonly known endocrine-disrupting compounds such as bisphenol A (BPA) and 17α-ethinyl estradiol (Ee₂) in a single-component aqueous solution using 28 and 580 kHz ultrasonic reactors. The experiments were conducted with three different types of model water: deionized water (DI), synthetic brackish water (SBW), and synthetic seawater (SSW) at pH 4, 7.5, and 11 in the presence of inert glass beads and humic acids. Significantly higher sonochemical degradation (93-97% for BPA) occurred at 580 kHz than at 28 kHz (43-61% for BPA), regardless of water type. A slightly higher degradation was observed for Ee₂ compared to that of BPA. The degradation rate of BPA and Ee₂ in DI water, SBW, and SSW after 30 min of ultrasound irradiation at 580 kHz increased slightly with the increase in pH from 4 (0.073-0.091 min-1 for BPA and 0.081-0.094 min-1 for Ee₂) to 7.5 (0.087-0.114 min-1 for BPA and 0.092?0.124 min-1 for Ee₂). In contrast, significant degradation was observed at pH 11 (0.149-0.221 min-1 for BPA and 0.147-0.228 min-1 for Ee₂). For the given frequencies of 28 and 580 kHz, the degradation rate increased in the presence of glass beads (0.1 mm and 25 g) for both BPA and Ee₂: 0.018-0.107 min-1 without beads and 0.052-0.142 min-1 with beads for BPA; 0.021-0.111 min-1 without beads and 0.054-0.136 min-1 with beads for Ee₂. A slight increase in degradation of both BPA and Ee₂ was found as the concentration of dissolved organic carbon (DOC, humic acids) increased in both SBW and SSW: 0.107-0.115 min-1 in SBW and 0.087-0.101 min-1 in SSW for BPA; 0.111-0.111 min-1 in SWB and 0.092-0.105 min-1 in SSW for Ee₂. After 30 min of sonicating the humic acid solution, DOC removal varied depending on the water type: 27% (3 mg L-1) and 7% (10 mg L-1) in SBW and 7% (3 mg L-1) and 4% (10 mg L-1) in SSW.

Fine mapping of grain weight QTL, tgw11 using near isogenic lines from a cross between Oryza sativa and O. grandiglumis

Ji‐Min Oh,Sangshetty Balkunde,Paul Yang,Dong‐Beom Yoon,안상낙 한국유전학회 2011 Genes & Genomics Vol.33 No.3

In our previous study, we reported the grain weight (GW)QTL, tgw11 in isogenic lines derived from a cross between Oryza sativa ssp. Japonica cv. Hwaseong and O. grandiglumis. The O. grandiglumis allele at tgw11 decreased GW in the Hwaseong background. To fine-map tgw11, one F5 plant homozygous for the O. grandiglumis DNA in the target region on chromosome 11 was selected from F_4 line,CR1242 segregating for tgw11 and crossed with Hwaseong to produce secondary F_2 and F_3 populations. QTL analysis using 760 F_2 plants confirmed the existence of tgw11 with an R^2 value of 15.0%. This QTL explained 32.2% of the phenotypic variance for GW in 91 F_3 lines. Substitution mapping with 65 F_3 lines with informative recombination breakpoints in the target region was carried out to narrow down the position of the tgw11. The result indicated that tgw11 was located in the 900-kb interval between two SSR markers, RM224 and RM27358. QTLs for grain width and grain thickness were also located in the same interval suggesting that a single gene is involved in controlling these three traits. Analysis of F3 lines indicated that the variation in TGW is associated with variation in grain shape, specifically grain thickness and grain width. Genetic analysis indicated that the O. grandiglumis allele for small seed was dominant over the Hwaseong allele. SSR markers tightly linked to the GW QTL would be useful in marker-assisted selection for variation in GW in breeding program.

Production and Characterization of Enzymes Involved in Chitin Catabolic Cascade from a Bacterial Strain Isolated from Soil

( Ji Hyun Lee ),( Jeong In Lee ),( So Yeon Park ),( Yoo Kyeong Jang ),( You Bin Lim ),( Hye Yoon Lee ),( Young Min Jung ),( Hae Chang Lee ),( Jong Hwa Lee ),( Shaheen Amna ),( Jae Kweon Park ) 한국키틴키토산학회 2019 한국키틴키토산학회지 Vol.24 No.1

The present study was aimed to isolate the bacteria producing chitinolytic enzymes including chitin deacetylase (CDA) from soil origin. About 24 bacteria were screened for their chitinolytic enzymes producing ability on the basis of colloidal chitin. Amongst one of the most potent isolates designated to JI-02 was further selected as the most prominent chitinolytic and CDAlike enzyme (CDA-X) producer based on the ability of deacetylation of an artificial substrate pNP-acetamilide. The maximum production of CDA-X in crude enzyme from JI-02 was observed in the presence of 1% colloidal chitin at 37°C and pH 6.4 after 120 h of incubation. Potent enzyme activity of CDA-X was determined toward pNP-acetamilide, demonstrating that optimal pH, temperature and ionic strength of the CDA-X were assessed to be 7.0, 52°C and 125 mM, respectively. Unexpectedly, Nacetylglucosamine (GlcNAc) was not fully converted by the action of CDA-X to glucosamine (GlcN) under the established conditions. Further study on enzyme activity toward chitin-oligosaccharides consisting of multi-N-acetylglucosamine (GlcNAc)n, n=2-5 may be necessary to elucidate the mode of action which requires the minimum size of (GlcNAc)n. However, our data suggest that CDA-X can convert chitin to chitosan with the maximum yield of approximately 0.08g/L during the fermentation of the strain in the presence of chitin. Furthermore, we found that crude enzyme showed the significant chitosanolytic activity. Taken together, our data suggest that the strain JI-02 may be a potential candidate as a particular strain for better understating of chitin catabolic pathway.

Chlorpropamide 2-hydroxylation is catalysed by CYP2C9 and CYP2C19 <i>in vitro</i>: chlorpropamide disposition is influenced by CYP2C9, but not by CYP2C19 genetic polymorphism

Shon, Ji-Hong,Yoon, Young-Ran,Kim, Min-Jung,Kim, Kyoung-Ah,Lim, Young-Chae,Liu, Kwang-Hyeon,Shin, Dong-Hoon,Lee, Chung Han,Cha, In-June,Shin, Jae-Gook Blackwell Science Ltd 2005 British journal of clinical pharmacology Vol.59 No.5

<P>Aims</P><P>We evaluated the involvement of cytochrome P450 (CYP) isoforms 2C9 and 2C19 in chlorpropamide 2-hydroxylation <I>in vitro</I> and in chlorpropamide disposition <I>in vivo</I>.</P><P>Methods</P><P>To identify CYP isoforms(s) that catalyse 2-hydroxylation of chlorpropamide, the incubation studies were conducted using human liver microsomes and recombinant CYP isoforms. To evaluate whether genetic polymorphisms of CYP2C9 and/or CYP2C19 influence the disposition of chlorpropamide, a single oral dose of 250 mg chlorpropamide was administered to 21 healthy subjects pregenotyped for CYP2C9 and CYP2C19.</P><P>Results</P><P>In human liver microsomal incubation studies, the formation of 2-hydroxychlorpropamide (2-OH-chlorpropamide), a major chlorpropamide metabolite in human, has been best described by a one-enzyme model with estimated <I>K</I><SUB><I>m</I></SUB> and <I>V</I><SUB>max</SUB> of 121.7 ± 19.9 µ<SMALL>M</SMALL> and 16.1 ± 5.0 pmol min<SUP>−1</SUP> mg<SUP>−1</SUP> protein, respectively. In incubation studies using human recombinant CYP isoforms, however, 2-OH-chlorpropamide was formed by both CYP2C9 and CYP2C19 with similar intrinsic clearances (CYP2C9 <I>vs.</I> CYP2C19: 0.26 <I>vs.</I> 0.22 µl min<SUP>−1</SUP> nmol<SUP>−1</SUP> protein). Formation of 2-OH-chlorpropamide in human liver microsomes was significantly inhibited by sulfaphenazole, but not by <I>S</I>-mephenytoin, ketoconazole, quinidine, or furafylline. In <I>in vivo</I> clinical trials, eight subjects with the <I>CYP2C9</I>*<I>1/</I>*<I>3</I> genotype exhibited significantly lower nonrenal clearance [*<I>1/</I>*<I>3 vs.</I>*<I>1/</I>*<I>1</I>: 1.8 ± 0.2 <I>vs.</I> 2.4 ± 0.1 ml h<SUP>−1</SUP> kg<SUP>−1</SUP>, <I>P</I> < 0.05; 95% confidence interval (CI) on the difference 0.2, 1.0] and higher metabolic ratios (of chlorpropamide/2-OH-chlorpropamide in urine: *<I>1/</I>*<I>3 vs.</I>*<I>1/</I>*<I>1</I>: 1.01 ± 0.19 <I>vs.</I> 0.56 ± 0.08, <I>P</I> < 0.05; 95% CI on the difference − 0.9, − 0.1) than did 13 subjects with <I>CYP2C9</I>*<I>1/</I>*<I>1</I> genotype. In contrast, no differences in chlorpropamide pharmacokinetics were observed for subjects with the <I>CYP2C19</I> extensive metabolizer <I>vs.</I> poor metabolizer genotypes.</P><P>Conclusions</P><P>These results suggest that chlorpropamide disposition is principally determined by CYP2C9 activity <I>in vivo</I>, although both CYP2C9 and CYP2C19 have a catalysing activity of chlorpropamide 2-hydroxylation pathway.</P>

D-Amphetamine이 니코틴성 흥분작용에 의한 카테콜아민 분비작용에 미치는 영향

임건한,서유석,민선영,임지연,김용직,나광문,임동윤 朝鮮大學校 附設 醫學硏究所 2005 The Medical Journal of Chosun University Vol.30 No.1

본 연구의 목적은 d-arphetamine이 흰쥐의 적출부신 관류모델에서 니코틴 수용체 흥분에 의한 카테콜아민(CA) 유리작용에 미치는 영향을 검색하여 그 작용기전을 규명하고자 하였다. D-amphetamine은 흰쥐 부신정맥내로 60분간 관류시 d-amphetamine자체는 약한 CA 분비작용을 나타내었으나, d-amphetamine (30 μM)을 비롯한 강력한 neuronal nicotine 수용체 작용제인 cytisine (50 μM) 및 epibatidine (30 μM)에 의한 CA 유리작용을 처음 4-10분 동안만 유의하게 증강시켰다. 또한, d-amphetamine (30 μM)은 60분간 부신정맥 내로 관류한 상태에서 dihydropyridine L-형 칼슘통로 개방약물인 Bay-K-8644 (10 μM)과 세포질내 칼슘저장고에서 Ca^(2+) ATPase 억제제인 cyclopiazonic acid (10 μM)의 CA 유리작용을 처음 4분간만 유의하게 증강시켰다. 그러나, 고농도의 d-amphetamine (500 μM)은 상기한 모든 분비촉진제의 CA분비작용을 오히려 억제하였다. 이와 같은 연구결과로 보면, 흰쥐 관류 부신수질에서 d-amphetamine은 낮은 농도에서는 콜린성 니코틴 수용체 흥분에 의한 카테콜아민 분비반응을 증강시키지만, 고농도에서는 오히려 억제적으로 작용함을 시사한다. 따라서, d-amphetamine은 용량에 따라서 흰쥐 적출 관류부신수질의 니코틴 수용체의 작용제 및 길항제로 이중 작용(dual action)을 나타내는 것으로 생각된다. 이러한 d-amphetamine의 작용은 흰쥐 부신수질 크롬친화세포의 dihydropyridine계 L-형 칼슘통로의 활성화 및 세포 내 칼슘저장고로부터 칼슘유리작용과 관련성이 있는 것으로 사료된다. The purpose of the present study was to examine the effect of d-amphetamine on CA release evoked by nocotinic receptor stimulation from the isolated perfused model of the rat adrenal gland, and to establish its mechanism of action. D-amphetamine(30 μM), when perfused into an adrenal vein of the rat adrenal gland for 60 min, enhanced the CA secretory responses evoked by ACh (5.32 mM), nicotine (30 μM), cytisine (50 μM, a selective neuronal nicotinic Nn-receptor agonist) and epibatidine (30 nM, a selective neuronal nicotinic Nn receptor agonist) only for the first period (4~10 min), although it alone has weak effect on CA secretion. Moreover, d-amphetamine (30 μM) in to an adrenal vein for 60 min also augmented the CA release evoked by BAY-K-8644, an activator of the dihydropyridine L-type Ca^(2+) channels, and cyclopiazonic acid, an inhibitor of cytoplasmic Ca^(2+) ATPase only for the first peroid (4 min). However, in the presence rather inhibited the CA secretory responses evoked by the above all of secretagogues. Taken together, these experimental results suggest that d-amphetamine at a low concentration enhances the CA secretion from the rat adrenal medulla evoked by stimulation of cholinergic nicotininc receptors, but at a high concentration it rather inhibits them. It semms that d-amphetamine has dual action acting as both agonist and antagonist at nicotinic receptors of the isolated perfused rat adrenal medulla, which are might be dependent on the concentration. It is also thought that these actions of d-amphetamine are probably relevant to the activation of the dihydropyridine L-type Ca^(2+) channels located on the rat adrenomedullary chromaffin cell membrane and release of Ca^(2+) from the cytoplasmic store.

Subcritical water extraction (SWE) of anthocyanin from blueberries (Vaccinium corymbosum)

Hye-Ji Kang,Seon-Woo Kim,Ha-Un Yoo,Na-Yeon Kim,So-Yoon Yee,Min-Jung Ko,Myong-Soo Chung 한국산업식품공학회 2017 학술대회 및 심포지엄 Vol.2017 No.11

Subcritical water extraction (SWE) is an eco-friendly new extraction technology because it does not contain harmful organic solvent and has high extraction efficiency in a short time compared with conventional extraction methods. Blueberries (Vaccinium corymbosum) are widely known as superfood due to rich source of anthocyanin (malvidin-3-o-galgctoside) and antioxidant activity. In this study, optimal extraction condition of SWE from blueberries was determined and compared with the conventional extraction methods. SWE was carried out using a Dionex Accelerated Solvent Extractor (ASE, Model 350) under conditions of temperatures (110, 130, 150 and 170°C) and times (1, 3, 5 and 10 min). Total anthocyanin of SWE extracts was compared with hot water (60°C, 1 h) extract and pressed juice extract. The total anthocyanin content was determined by pH differential method. Considering both the extraction time and temperature conditions, the highest content of total anthocyanin content was 0.455 mg/g FW Vaccinium corymbosum at 130°C for 3 min. At high temperature and long extraction time, the anthocyanin in the blueberries will undergo thermal degradation due to low stability of anthocyanin at extreme condition. Besides, maximum yield of anthocyanin from blueberries using SWE was about 1.2 and 3.8 times more higher than hot water extract and pressed juice extract, respectively. Therefore, SWE is faster and more efficient method to extract anthocyanin from blueberries than conventional extraction methods. This study shows a possibility of SWE applied to food processing industry.

물리ㆍ화학적 처리에 의한 멸균 초콜릿 우유 오염균의 생육억제 효과

최문경(Moon-Kyoung Choi),윤소영(So-Young Yoon),이소영(So-Young Lee),김꽃봉우리(Koth-Bong-Woo-Ri Kim),이청조(Chung-Jo Lee),정지연(Ji-Yeon Jung),곽지희(Ji-Hee Kwak),김민지(Min-Ji Kim),김동현(Dong-Hyun Kim),선우찬(Chan Sunwoo),이주운(Ju-W 한국식품영양과학회 2011 한국식품영양과학회지 Vol.40 No.8

멸균 초콜릿 우유로부터 분리한 내열성 균주에 대해 열, pH, 전해수, 오존처리, microwave 및 감마선 처리를 하여 균주의 사멸효과에 대해 알아보았다. 균주의 지방산 분석과 API kit를 통하여 균주를 동정한 결과, Bacillus lentus로 동정되었으며, 잠정적으로 Bacillus lentus M1으로 명명하였다. B. lentus M1에 110℃, 15분간 열처리하였을 경우 생육이 억제되었으며, pH 처리 시 pH 5 이하, 10 이상에서 생육이 억제된 것으로 나타났다. B. lentus M1에 대한 전해수의 항균활성을 paper disc법으로 측정한 결과, 높은 생육억제를 보였으며, 오존 처리의 경우 초기 균수가 10² CFU가량의 균을 10분 동안, 10³ CFU가량의 균을 30분 동안 처리 시 균의 생육이 억제되는 것으로 나타났다. Microwave를 1분간 처리 시 B. lentus M1이 모두 사멸한 것으로 나타났다. 감마선 조사의 경우, 1 kGy 조사 시 생균수가 1.61×10³ CFU로 초기 균수에 비해 4 log cycle 가량 균수가 감소하였으며 7 kGy에서 완전히 사멸하였다. 이상의 결과를 통해 열, pH, 전해수, 오존 처리 및 방사선 처리 방법이 멸균 초콜릿 우유의 생존 오염균인 B. lentus M1을 효과적으로 사멸시킬 수 있을 것으로 사료된다. This study was conducted to investigate the cause of microbiological contaminants in aseptic chocolate milk and evaluate the effect of a physicochemical treatment on the growth inhibition of isolated bacterial strains. The bacterium isolated from aseptic chocolate milk was identified as Bacillus lentus and was named B. lentus M1. In the heat and pH treatment, the growth of B. lentus was inhibited at 110℃ for >15 min and at pH’s <5 and >10. An electrolyzed water treatment against B. lentus M1, revealed 5 ㎜ growth past the inhibition zone. The effect of ozone gas on B. lentus M1 growth was evaluated using viable cell counts. When the initial number of B. lentus M1 was 10² and 10³ CFU, the bacteria were completely suppressed by ozone gas treatment for 10 and 30 min, respectively. In a microwave treatment, B. lentus M1 was sterilized following microwave treatment for 1 min. As the result of γ-irradiation against B. lentus M1, numbers decreased as the γ-irradiation dosage increased. These results show the growth inhibition effects against contaminants in aseptic chocolate milk using physicochemical treatments.

Free Paper Presentation : OS-111 ; The Effects of Dexmedetomidine for Sleep in Critically Ill Patients: Pilot Study

( Se Joong Kim ),( Jin Soo Min ),( Ji Soo Park ),( Yeon Joo Lee ),( Jong Sun Park ),( Ho Il Yoon ),( Jae Ho Lee ),( Choon Taek Lee ),( Young Jae Cho ) 대한결핵 및 호흡기학회 2014 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.118 No.-

Background: Many critically ill patients in the intensive care unit (ICU) experience sleep disruption and delirium. For the sedation of these patients, dexmedetomidine is one of commonly recommended sedatives because of its pharmacokinetic merit. This pilot study was undertaken to identify the effects of dexmedetomidine for sleep and delirium in critically ill patients. Methods: This prospective study was conducted in medical ICU of a tertiary referral hospital. Dexmedetomidine was administered with the maintenance dose of 0.4-0.7μg/kg/hr and adjusted by Richmond Agitation Sedation Scale score of 0 to -2. Portable polysomnography was performed in the ICU over 24 hour to assess the quantity and quality of sleep. The confusion assessment method for ICU was used for detection of delirium. Results: Total 9 patients were enrolled. Median age was 77.0 (Range: 61-90) and 3 patients experienced delirium. Median total sleep time was 283 (IQR: 56-739) min. The majority of sleep was stage 1 (median 208 [IQR: 56-356] min) and 2 (median 75 [IQR: 7-396] min) with absent REM and stage 3 sleep. The dose of dexmedetomidine was not associated with total sleep time, stage 1 and stage 2 sleep (all P>0.05). However, the patients with delirium was administered higher dose of dexmedetomidine than ones without delirium (0.67μg/kg/hr vs 0.33μg/kg/hr, P=0.006). Conclusions: Although proper sedation was met with dexmedetomidine, the quantity and quality of sleep in critically ill patients were poor. Further study is required for the promotion of good sleep and the prevention of delirium in ICU patients.

이동형 스크러버를 이용한 암모니아 및 톨루엔의 제거 효율

김재영 ( Jae-young Kim ),김장윤 ( Jang-yoon Kim ),이연희 ( Yeon Hee Lee ),김민선 ( Min Sun Kim ),김민수 ( Min-su Kim ),김현지 ( Hyun Ji Kim ),류태인 ( Tae In Ryu ),정재형 ( Jae Hyeong Jeong ),황승율 ( Seung-ryul Hwang ),김균 ( Ky 한국환경농학회 2018 한국환경농학회지 Vol.37 No.1

본 연구는 국내에서 다량 취급되고 있는 암모니아 및 톨루엔을 흄 상태로 노출시킨 후 흡수/흡착방법을 달리한 이동형 스크러버를 이용해 각 유해화학물질의 제거효율을 비교 분석하였다. 이동형 스크러버는 기 개발된 장치를 개선하여 와류세정에 의한 흡수, 유입풍속 조절의 장점을 살리고, 활성탄 및 카본필터를 통한 기체상 유해화학물질의 흡착방법 도입을 통해 단점을 보완하였다. 개선된 장치는 기초성능평가를 통해 적정 제어풍속이 검증되었고, 5% 암모니아수 용액을 흄 상태로 노출시켜 후드 흡입부, 송풍기 배출부 및 세정기가 정상 작동함을 확인하였다. 흡수/흡착방법에 따른 암모니아 제거효율은 90분 경과 후 C≥PCA>SWA 순으로 가장 우수한 SWA 군의 노출 농도별 제거 효율은 시간이 경과할수록 노출 농도와 무관하게 배출 농도는 증가되었고, 세정액의 pH는 산성에서 염기성으로 변화되었다. 또한, 시간 경과에 따른 노출 농도 별 세정액의 pH 변화와 배출구 농도 변화 사이에 0.9429~0.9491 수준의 정의 상관관계를 나타내었다. 흡착방법에 따른 톨루엔의 제거 효율은 초기 10분 경과 후 배출구농도에서 C>CMA≥GCA 순을 나타내다 90분 경과까지 일정한 농도로 유지되었다. 가장 우수한 GCA 군의 노출 농도 별 제거 효율은 초기 10분 경과 시 노출 농도에 비례하여 배출 농도가 높은 경향이었다. 이와 같은 결과를 통해 개선된 이동형 스크러버는 중화반응에 의해 산성 또는 염기성 유해화학물질의 제거뿐 아니라, 활성탄 등의 흡착기능 개선을 통해 VOCs 제거에도 효과적이었다. 하지만, 실제 현장에서 활용이 가능하도록 세정액 pH를 지속적으로 유지하여 연속적으로 흡수 제거할 수 있는 방법과 노출되는 화학물질 농도와 흡착제의 관계에서 파괴점, 포화점, 흡착속도 등의 물리적인 요소가 추가적인 연구를 통해 도출되어야 할 것이다. BACKGROUND: The mobile vortex wet scrubber was developed to remove the harmful chemicals from accidental releases. However, there was a disadvantage that it was limitedly used for volatile organic compounds (VOCs) such as toluene according to the physicochemical properties. This study compared the removal efficiencies of an improved mobile scrubber on toluene and ammonia by applying diverse adsorption and absorption methods. METHODS AND RESULTS: The removal efficiencies on harmful chemicals were examined using various adsorption and absorption methods of water vortex process (C), phosphoric acid-impregnated activated carbon adsorption (PCA), pH-controlled water (pH 2.5) vortex process absorption with sulfuric acid (SWA) after ammonia exposure, granular activated carbon adsorption (GCA), and activated carbon mat adsorption (CMA) after toluene exposure. As a result, the best removal efficiency was shown in the SWA for ammonia and GCA for toluene. Also, the SWA and GCA methods were compared with different concentration levels. In the case of ammonia exposure (5, 10 and 25%), there was no difference by concentration levels, and the concentration in the outlet gradually increased, with pH change from acid to base. In the case of toluene exposure (50, 75 and 100%), the outlet concentration was higher relative to the exposure concentration in the initial 10 min, but the outlet concentration was remained steady after 10 min. CONCLUSION: The newly improved mobile scrubber was also effective in removing VOCs through adsorption techniques (activated carbon, activated carbon fiber, carbon mat filter etc.), as well as removing acid-base harmful chemicals by neutralization reaction.

물리․화학적 처리에 의한 요구르트 오염균의 생육 억제효과

선우찬(Chan Sunwoo),이소영(So-Young Lee),윤소영(So-Young Yoon),정지연(Ji-Yeon Jung),김꽃봉우리(Koth-Bong-Woo-Ri Kim),이청조(Chung-Jo Lee),곽지희(Ji-Hee Kwak),김민지(Min-Ji Kim),김동현(Dong-Hyun Kim),정슬아(Seul-A Jung),김현지(Hyun-Jee 한국식품영양과학회 2011 한국식품영양과학회지 Vol.40 No.12

물리?화학적 처리에 의한 요구르트 오염균의 생육억제 효과를 알아보기 위해, 요구르트의 주요 오염균을 분리?동정하고, 열, pH, 전해수, 오존가스, microwave 처리 및 감마선을 조사하여 오염균주에 대한 사멸효과를 알아보았다. 오염된 요구르트로부터 분리한 효모의 지방산 조성 분석과 API(Analytic Profile Index) kit 분석을 실시한 결과, Hanseniaspora uvarum으로 동정되었으며 잠정적으로 Hanseniaspora uvarum Y1으로 명명하였다. H. uvarum Y1의 열 및 pH 처리에 의한 생육억제 효과를 측정한 결과, 70℃ 및 80℃에서 15분 가열처리로 균이 사멸되었으며, pH 처리 시 pH 2, 3 및 9에서 생육이 다소 억제되었으며, pH 1 및 10에서 완전히 억제되었다. 전해수 처리의 경우, clear zone이 5 mm 이상으로 H. uvarum Y1이 전해수에 높은 감수성을 가지는 것으로 나타났다. 오존가스 처리에 의한 H. uvarum Y1의 사멸효과를 측정한 결과, 102 CFU의 균은 10분, 103 CFU의 균은 20분 처리 시 모두 사멸한 것으로 나타났으며, microwave 처리의 경우, 106 CFU 가량의 균이 1분 처리 시 모두 사멸되었다. 방사선 조사의 경우, 균수를 90% 이상 감소시키는데 필요한 조사선량이 20 kGy 이상으로 H. uvarum Y1은 감마선에 저항성이 있는 균임을 알 수 있었다. 이상의 결과를 종합해볼 때 열, pH, 전해수, 오존가스, microwave 처리를 통해 요구르트 오염균주인 H. uvarum Y1의 생육을 효과적으로 억제할 수 있을 것으로 생각된다. This study was conducted to investigate the cause of microbiological contamination in yogurt and evaluate the effect of physicochemical treatment on the growth inhibition of Hanseniaspora uvarum isolated from yogurt. The yeast strain Hanseniaspora uvarum Y1 was subjected to heat and pH treatments. H. uvarum Y1 was killed at 70oC and 80oC after 15 min and survived in a wide pH range from pH 2 to 9. However, it did not survive under pH 1 and over pH 10. In a disk diffusion susceptibility test on H. uvarum Y1, a clear zone (5 mm) of growth inhibition was observed upon treatment with electrolyzed water. The effect of ozone gas on the growth of H. uvarum Y1 was evaluated by viable cell count. Initial cell numbers of 102 and 103 CFU/mL of H. uvarum Y1 were completely killed by treatment for 10 and 30 min, respectively. H. uvarum Y1 was also sterilized by microwave treatment for 1 min. When treated with gamma-irradiation, the rate of killing of H. uvarum Y1 was proportional to the irradiation dose. and complete killing occurred at a dose of 50 kGy.