Salmonella sp.의 신속한 동정을 위한 증진배양의 개선에 관한 연구

김기태,김태우,옥순학,이영호,백운화 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.6

식품 및 생활폐수내의 존재하는 Salmonella spp.에 대한 효율적이고 신속한 동정을 위한 증진배야업을 개발하고자 하였다. 본 연구에 사용된 균주인 S. enteritidis 생육을 촉진시키기 위한 방법으로 cAMP 및 yeast extract를 사용하였는데 전자인 경우는 배지내의 농도가 10 mM 이상일 때 10^-3 cfu/ml의 균수로 7시간 배양후 균수가 control보다 약5배의 증가를 보였으며 후자인 경우는 0.6% 첨가시 10배의 증가를 보였다. 다른 균주들에 대한 선택적인 성장효과를 보기위하여 selenite broth와 bile salts를 사용하였고 이때 사용된 균주는 Staphylococcus aureus, Pesudomonas aeruginosa, Lactobacillus plantarum 및 Escherichia coli이었고 bile salts의 농도가 0.1%일때 네 가지 균주의 증식에 대한 억제 효과가 있었다. 두 단계의 증진배양법으로서 1차 증진배양에서는 selenite broth에 0.6% yeast extract를 첨가한 것으로 2차 증진배양에서는 0.1% bile salts를 첨가한 것으로 하였는데 타균과의 혼합배양에서 Salmonella의 초기균수가 10^0.3일 때 14시간 증진배양으로 10^8.5 cfu/ml까지 증식을 보였으며 초기균수가 1 cfu/100 ml인 경우는 10시간의 1차 증진배양과 6시간의 증진배양으로 약 10^7의 증식속도를 나타내었다. The development of an enrichment method for the rapid and effective identification of Salmonella spp. in sewage or food was studied. As a growth factor for Salmonella, 10 mM cyclic adenosine monophosphate (cAMP) in trypticase soy broth with 0.6% yeast extract (TSBYE) increased cell number five-folds and 0.6% yeast extract in selenite broth increased cell number ten-folds of control. Bile salts in slenite broth was tested for the selection of S. enteritidis in a mixture with Staphylococcus aureus, Pesudomonas aeruginosa, Lactobacillus plantarum and Escherichia coli. The latter four strains were effectively inhibited at 0.1% bile salt. A two-step culture method was used to enrich Salmonella spp.; a primary-enrichment and secondary-enrichment culture. At a primary-enrichment step, selenite broth with 0.6% yeast extract and 10 mM cAMP was used, and at a secondary-enrichment step, -0.1% bile salt was additionally used. Culture times of a primary-enrichment and a secondary-enrichment step were 8 hr and 6 hr, respectively. In this procedure, cell number increased from 10^0.3 to 10^8.5 with inhibition of other strains within 14 hr. In the case of an initial cell concentrarion as low as 10^-2 cfu/ml, a cell number increased to 10^7 cfu/ml by using a 10 hr primary-enrichment and 6 hr secondary-enrichment procedure.

연구발표 초록 ( 공정시스템 (Ⅱ) ) : 최소 접근 온도의 최적화를 통한 열교환망 연구

백운화,김상우,이해평,박선원 ( Un Hua Pek,Sang Woo Kim,Hae Pyeong Lee,Sun Won Park ) 한국화학공학회 1991 추계학술발표회 Vol.- No.-

Characteristics of Low - Fat Cheddar Cheese Made with Added Micrococcus sp .

Si Kyung Lee,Un Hua Pek,Hyun Kyu Joo,Elmer H . Marth 한국응용생명화학회 1992 한국응용생명화학회 학술발표회 Vol.1992 No.-

The main purpose of this study was to determine the effects of Micrococcus sp. LL3 on accelerating proteolysis, flavor development and characteristics of low-fat Cheddar cheese as a potential agent for industrial application, and to optimize cultural conditions for cell mass production. Optimum temperature for cell growth and caseinolysis was 30 ℃ and 35 ℃ respectively, and optimum pH was 7.0. Monosaccharides like glucose, mannose and fructose were more excellent as carbon source, but arabinose and xylose markedly inhibited cell growth and caseinolysis. Among the organic nutrients, yeast extract was more effective for cell growth and for caseinolysis. However, inoranic nitrogen sources were less effective than organic sources. Urea inhibited cell growth severely. Cell growth and caseinolysis were rather increased a little in broth containing 1% NaCl, and Micrococcus sp. LL3 was very tolerant until NaCl concentration in broth added to 9%. Addition of vitamin did not affect cell growth and caseinolysis in level of 0.1 ㎍/㎖ concentration. Cell growth and caseinolysis were activiated by addition of glutamic acid and MgSO₄ with concentration of 0.2% and 0.5% respectively. Production of aminopeptidase which cleaved polypeptides was the highest in early stationary phase during cell growth. There was no difference in acidity changes in the course of cheese manufacture and in chemical component in 6-month old cheese through addition of Micrococcus sp. LL3 to cheese. It was however possible to note a significant increase in the value for TCA solube N and PTA soluble N in cheese with added adjunct compared to the control cheese. Values for TCA soluble N were 14, 21 and 28% higher khan that of the control cheese for 6-month old cheeses with added CFE, FD and live cells of Micrococcus sp. LL3. Using electrophoresis in polysacrylamide gels, casein hydrolysis appeared also to be more extensive in experimental cheeses ripened at 10 ℃ for 5 and 6 months than in the control cheese. The population of starter and lactic acid bacteria was not affected by addition of Micrococcus sp. LL3 as ajunct. Starter bacteria decreased slowly but lactic acid bacteria increased rapidly with time. Microflora of 3-month old low-fat Cheddar cheese represented a sequene of changes in which Lactobacillus sp. replaced the initial flora of Streptococcus sp. When Micrococcus sp. LL3 was added in cheese, no marked flavor defects developed and bitterness decreased more than in control cheese. Panelists gave higher flavor score and overall preference score to experimental cheeses than to the control cheese.

하이드록시프로필화 옥수수 전분의 호화 및 겔 특성

육철(Cheol Yook),백운화(Un-Hua Pek),박관화(Kwan-Hwa Park) 한국식품과학회 1991 한국식품과학회지 Vol.23 No.3

하이드록시프로필화 및 가교화 시킨 옥수수 전분의 호화 및 겔 특성

육철(Cheol Yook),백운화(Un-Hua Pek),박관화(Kwan-Hwa Park) 한국식품과학회 1992 한국식품과학회지 Vol.24 No.1

Microbial BOD Sensor Using Hansenula anomala

Ihn Gwon-Shik,Park Kyung-Ho,Pek Un-Hua,Sohn Moo-Jeong Korean Chemical Society 1992 Bulletin of the Korean Chemical Society Vol.13 No.2

A microbial sensor for BOD (Biochemical Oxygen Demand) measurement has been developed by immobilizing Hansenula anomala in a polyacrylamide gel. The optimum pH and temperature for BOD measurement using this sensor were pH 7.0 and $30^{\circ}C$, respectively. The response time was 30 min. A linear relationship was observed between the potential and the concentration below 44 ppm BOD. The potential was reproducible within ${\pm}9%$ of the relative error when a sample solution containing 20 mg/l of glucose and 20 mg/l of glutamic acid was employed. The effect of various compounds on BOD estimation was also examined. The potential output of the sensor was almost constant for 30 days. The relative error in BOD estimation was within ${\pm}10%$.

봄배추의 收穫後 品質 및 색깔 變化에 미치는 CA 貯藏의 效果

梁容準(Yang Yong-Joon),白雲和(Pek Un-Hua) 한국원예학회 1996 Horticulture, Environment, and Biotechnology Vol.37 No.5

하이드록시프로필화 옥수수 전분의 이화학적 특성

육철,백운화,박관화,Yook, Cheol,Pek, Un-Hua,Park, Kwan-Hwa 한국식품과학회 1991 한국식품과학회지 Vol.23 No.2

옥수수 전분을 propylene oxide와 반응시켜 치환도가 $0.031{\sim}0.147$되는 hydroxypropyl 옥수수 전분을 제조하여 물리화학적 특성을 규명하였다. Hydroxypropylation에 의하여 팽윤력, 용해도 및 물결합 능력이 증가하고 생전분의 효소 분해력이 높아졌으며 요오드 흡착강도가 낮아졌다. 아울러 hydroxypropylation에 의하여 전분의 결정화도도 감소되었다. 한편, 옥수수 전분을 hydroxypropylation시켰을 때 분자량 $1.34{\times}10^7$ 이상의 큰 분자는 감소하였고 $1.34{\times}10^7{\sim}1.18{\times}10^5$의 전분 분자는 증가하였다. Hydroxypropylation에 의하여 옥수수 전분 입자의 형태에는 별 변화가 없었으나 입자크기는 평균입경이 $13.9\;{\mu}m$에서 $16.0\;{\mu}m$로 증가하였다. Hydroxypropylated starches were prepared by reaction of corn starch with propylene oxide and their physicochemical properties were compared with those of the native starch. Swelling power, solubility and water binding capacity increased with the increase of hydroxypropylation. The hydroxypropylation of corn starch significantly reduced the extent of digestion and iodine absorption. Starch molecules larger than $1.34{\times}10^7{\sim}$ decreased whereas molecules ranging from $1.34{\times}10^7{\sim}1.18{\times}10^5$ increased by hydroxypropylation. Granule size increased by hydroxypropylation but this did not significantly affect the granule surface appearance by SEM. The hydroxypropylation improved the solubility and water binding capacity of corn starch.

고초균으로부터 β - glucanase 유전자의 분리 및 대장균에서의 발현

서연수,이영호,백운화 ( Yeon Soo Seo,Young Ho Lee,Un Hua Pek ) 생화학분자생물학회 1985 BMB Reports Vol.18 No.4

A gene coding for β-glucanase which can specifically hydorlyze barley β-glucan and lichenan was isolated from Bacillus subtilis ATCC6633 by molecular cloning using a plasmid vector pBR325. 2.1 Kb BamHI-HindIII DNA fragment conferred β-glucanase activity on Escherichia coli HB101 and 1.7 Kb PstI DNA fragment included in 2.1 Kb fragment gave rise to β-glucanase producing colonies, while its expression depended upon its inserting orientation in pUC9. This gene directed efficiently the synthesis of β-glucanase in E. coli. Up to 2496 of total activity was found outside of the cells. Fine restriction map was also constructed for further sequencing analysis. The transcriptional direction of cloned β-glucanase gene was determined and its putative functional unit could be deducted from the molecular weight of β-glucanase and by deletion mapping.

산업용 효모에서 Bacillus subtilis Endo-β-1,4-Glucanase의 생합성 및 분비

박용준,이영호,강현삼,백운화 한국산업미생물학회 1991 한국미생물·생명공학회지 Vol.19 No.4

Bacillus subtilis의 β-1,4-glucanase 유전자와 Saccharomyces cerevisiae의 alcohol dehydrogenase isoenzyme I 유전자(ADHI)의 promoter와 mouse α-amylase의 분비신호를 연결하여 분비형 플라스미드를 구성하였으며 이를 산업용 알콜생산 효모인 Saccharomyces cerevisiae 54에 도입하여 형질전환시켰다. 한편 β-glucanase 유전자의 발현정도를 증대시키기 위해 CYCI 유전자의 전사종결신호를 부가한 후 역시 Saccharomyces cerevisiae 54에 도입하였다. 형질전환체들은 carboxymethyl cellulose가 함유된 평판배지에서 β-glucanase를 분비하고 있음을 확인할 수 있었다. 전사종결 신호가 부가된 경우엔 전체역가가 2배정도 증가하였다. 형질전환체들이 세포밖으로 분비한 효소역가는 전체의 60% 정도였다. DNA segment encoding β-1,4-glucanase of Bacillus subtilis was fused in frame to mouse α-amylase signal sequence behind the alcohol dehydrogenase isoenzyme I gene (ADHI) promoter of the yeast expression vector pMS12. To enhance the expression level of the β-glucanase gene in yeast, transcription terminator sequence iso-1-cytochrome c gene (CYCI) was inserted into the recombinant plasmid. The transformants harbouring such recombinant plasmids secreted β-glucanase into the culture medium. The expresstion level of the β-glucanase gene was increased about 2-fold caused by inserting the terminator. The amount of the secreted β-glucanase in culture medium was approximately 60% of the total quantity synthesized.