• Journal of Microbiology and Biotechnology
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• 제33권12호
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• pp.1671-1680
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• 2023

The gluten protein content in whole-wheat flour is low, which affects the elasticity and viscosity of the dough. Enzymatic modification of the protein may result in a network that mimics gluten, which plays an important role in the processing of whole-wheat foods. In this study, the effects of Halomonas alkaliantartica laccase (LacHa) on the quality parameters of whole-wheat bread were investigated. The optimum dosage of LacHa was 4 U/100 g of whole-wheat flour. At this dosage, whole-wheat bread exhibited the best specific volume and optimum texture parameters. Laccase also extended the storage duration of whole-wheat bread. We analyzed the micro-structure of the dough to determine its gluten-free protein extractable rate and free sulfhydryl group content, and verify that LacHa mediates cross-linking of gluten-free proteins. The results demonstrated that the cross-linking of gluten-free protein by LacHa improves the texture of whole-wheat bread. As a flour improver, LacHa has great developmental and application potential in baked-food production.

• Applied Biological Chemistry
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• 제39권6호
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• pp.443-448
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• 1996

xylA 유전자의 프로모터상에서 조절양상을 조사하기 위하여 xylA 유전자의 프로모터(Pxyl)와 lacZ 유전자를 연결한 Pxyl-lacZ 융합 유전자를 제작하여 xylose에 의한 ${\beta}-galactosidase$ 생산의 조절양식을 조사하였다. xylA 프로모터 부위를 분리하여 lac 프로모터가 없는 고복제수의 lac 오페론 백터인 pMC1403에 클로닝시켜 pMCX191을 제작하여 reading frame에 변화가 없는 Pxyl-lacZ 융합 유전자를 만들었으며 이 벡터에서 Pxyl-lacZ 단편을 분리한 후 저복제수 벡터인 pLG339에 클로닝시켜 pLGX191을 제작하였다. 상기 플라스미드들을 xylA 변이주인 DH77에 형질전환시켜 Pxyl-lacZ 융합 유전자에서 ${\beta}-galactosidase$의 발현조절을 조사한 결과 xylose 농도에 따른 유도, glucose에 의한 발현억제 및 cAMP에 의한 억제해제 양상 등이 염색체상의xylA 유전자의 발현조절과 같은 경향을 나타내었다. pMCX191과 pLGX191을 이용하여 유전자 투여 량 효과를 본 결과도 복제수에 따른 차이가 크지 않았다. xylA 프로모터 부위내 조절영역를 추정하기 위해 구조유전자 상류 -209 bp를 포함한 xylA 유전자를 pUC19에 클로닝시킨 pUX30에서 프로모터 부위가 부분결손된 벡터들을 제작하여 결손부위의 염기서열을 확인하였다. 이들 부분결손 xylA 프로모터를 가진 xylA 유전자에서 xylose isomerase의 발현을 조사한 결과, 번역 개시점에서 -166 bp 이상의 영역을 결손시킨 pUX31과 pUX32의 경우pUX30과 비슷한 발현 양상을 보인 반면 -120 bp 이상의 영역을 결손시킨 pUX33과 pUX34에서는 모벡터에 비해 약 30% 수준의 발현을 보였다. 또한 pUX33과 pUX34에서는 xylose 유도시 cAMP에 의한 발현 촉진효과도 볼 수 없었다. -59 bp 이상의 부위가 결손된 pUX35의 경우에는 전혀 xylA 유전자의 발현이 일어나지 않았다. 이러한 결과로 볼때 xylA 프로모터내의 조절부위는 -165 bp에서 -59 bp 사이에 존재하는 것으로 추정되었다.

• Journal of Astronomy and Space Sciences
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• 제13권1호
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• pp.19-31
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• 1996

We have analyzed collected photoelectric light curves for light variations of SW Lac. The method of Fourier analysis was adopted to quantify the light variation from season to season. We found the linear relation between the Fourier coefficient, B1 and the magnitude difference between two maxima. The total light of the system has been decreased as much as 0m.04 during approxiamately 20 years time interval. Photoelectric parameters including spot parameters for all light curves were obtained by the method of the Wilson and Devinney differential correction in order to secure the variations of parameters from season to season. SW Lac, not like RS CVn type stars, required to adjust all parameters as well as spot parameters for a reasonable fit to the observations of each epoch. A surface temperature of cooler star is one of the most sensitive parameters to affect a shape of light curve of SW Lac. We conclude that the shape of light curve of SW Lac varies even during one season as well as season to season. The light curve is mainly caused by inhomogeneous surface temperature due to strong chromospheric activity of the system.

• Journal of Microbiology and Biotechnology
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• 제4권2호
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• pp.155-159
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• 1994

Two Zymomonas mobilis strains (ZM63 and ZM6307), containing both lactose and galactose operons, were constructed. $\beta$-Galactosidase and galactokinase assays indicated that both operons were expressed in both strains. The transport systems available for lactose uptake by Zymomonas mobilis were investigated using $^{14}C$-labelled lactose. After the outer membrane, which was considered to be a possible barrier to lactose uptake, was disrupted by treatment with EDTA and $Ca^{2+}$ ions, some increase in lactose uptake was observed in ZM6306 ($lac^+$) and ZM6307 ($lac^+\;gal^+$), but not in the parent, ZM6. This suggested that the outer membrane of Zymomonas mobilis acts as a barrier to lactose uptake to some degree, and also that the lactose permease is operational in Zymomonas mobilis.

• 패션비즈니스
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• 제18권4호
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• pp.114-124
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• 2014

This research was carried out to find the mordant effects by Tara and Myrobalan as natural tannins on the cow leather dyed with Lac powder. The cow leathers were treated with Tara, Myrobalan, Al, Cu, and Fe mordants by changing treatment orders. It was examined for K/S value, surface color changes, and color difference. The K/S value generally has higher Myrobalan than Tara, and pre-mordant than post-mordanted condition. Cu is the strongest among the three mordants. As a results of the treatment order, the K/S value is higer in pre-tannin-mordant agent than in pre-mordant agent-tannin. In the post mordant, K/S value is higher in mordant agent-tannin than in tannin-mordant agent. The color difference and color factors such as H, V and C were various according to the mordant agents, treatment orders and mordant methods; and surface colors of dyed cow leathers were R and RP. It was difficult to find some significant means of mordant orders.

• 한국식품영양과학회지
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• 제27권3호
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• pp.455-460
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• 1998

This study was carried out to investigate antimicrobial activities of ethanol extracts from 12 kinds of spices against Lactobacillus plantarum and Leuconostoc mesenteroides to kimchi fermentation. Lactic acid bacteria were isolated from fermenting kimchi, were identified as Leu. mesenteroides, Lac. sake, Lac. plantarum and Pediococcus pentosaceus. The ethanol extracts of cardamon, thyme and cumin among 12 spices showed antimicrobial activities against Lac. plantarum, while they did not showed the activites against Leu. mesenteroides through paper disc method. In addition, the growth of Lac. plantarum was inhibited in MRS broth containing each of cardamon(>4%), thyme(>4%) an cumin(>1%).

• KSBB Journal
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• 제5권3호
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• pp.195-200
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• 1990

대장균의 lipoprotein promoter, lactose promotor 및 operator 와 lipoprotein의 signal sequence 를 가지는 vector에alpha-IFN 유전자가 cloning된 plasmid pIF-Ill-B를 여러종류의 대장균 숙주 세포에 형칠전환하여 alpha-IFN 의 생산성, 생장특성을 조사하였다. 또한 plasmid 자체와 cloning된 alpha-IFN 유전자의 발현유도가 세포생장에 미치는 영 향을 조사하였다.

• 한국식품영양학회지
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• 제12권1호
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• pp.69-76
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• 1999

In order to screen lactic acid bacterial starter having high antibacterial activity and giving good flavor in Dongchmi for Naengmyon antibacterial activity and acid producing ability of 24 strains of Kimchi lactic acid bacteria were tested. Among 24 strains tested Leuconostoc mesenteroides subsp. mesenteroides C16, Leu. paramesenteroides C18 Lactobacillus bavaricus B01, B06, C19, C32 Lac. homohiochii B21 and B22 showed high antibacterial activity and their antibacterial activities were more active against Listeria monocytogenes and Staphylococcus aureus than against Escherichia coli and Salmonella typhimurium. The odors of Dongchimi-juices fermented with Leu. mesenteroides or Leu. paramesenteroides were more favorable than those with Lac. bavaricus or Lac. homohiochii. But the odors of Naengmyon-broths which were made with each Dongchimi-juice were not significantly different each other. In consideration of antibacterial ac-tivity and flavor of Dongchimi-juice two strains of lactic acid bacteria Lac. homohiochii B21 and Leu. mes-enteroides subsp. mesenteroides C16 were finally screened out as Dongchimi starters.

• 한국식품과학회지
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• 제53권3호
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• pp.348-355
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• 2021

Bacteriophages (phages) are known determinants of kimchi microbial ecology. Lactobacillus plantarum is related to kimchi over-acidification during the late stages of kimchi fermentation. A phage infecting Lac. plantarum was isolated from kimchi and characterized. The phage population for kimchi in a market was 2.3 log particles/mL, which corresponded to 32% of the bacterial population on a log scale. The isolated phage was designated as ΦLP12116. ΦLP12116 which belonged to the Siphoviridae family and has a very narrow host range, infecting only Lac. plantarum. The phage was stable at a lactic acid concentration of 1.0% and pH 4.0 at 4℃, indicating that it could survive in kimchi. In the kimchi extract broth treated by the phage, the growth of Lac. plantarum KCCM 12116 was inhibited by 2.2 log CFU/mL compared to the growth in non-phage-treated broth. Therefore, this study suggests that the growth of Lac. plantarum, which is known as an acid-producing strain during late fermentation in kimchi, may be controlled using the phage.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2006년도 The 5th Biannual Meeting of Pacific Rim Society for Fertility and Sterility
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• pp.176.2-176.2
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• 2006