• Title/Summary/Keyword: claR

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Enhanced Clavulanic Acid Production in Streptomyces clavuligerus NRRL3585 by Overexpression of Regulatory Genes

  • Hung, Trinh Viet;Ishida, Kenji;Parajuli, Niranjan;Liou, Kwang-Kyoung;Lee, Hei-Chan;Sohng, Jae-Kyung
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.2
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    • pp.116-120
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    • 2006
  • We constructed four recombinant plasm ids to enhance the production of clavulanic acid (CA) in Streptomyces clavuligerus NRRL3585: (1) pIBRHL1, which includes ccaR, a pathway-specific regulatory gene involved in cephamycin C and CA biosynthesis; (2) pIBRHL2, containing claR, again a regulatory gene, which controls the late steps of CA biosynthesis; (3) pGIBR containing afsR-p, a global regulatory gene from Streptomyces peucetius; and (4) pKS, which harbors all of the genes (ccaR/ claR/ afsR-p). The plasmids were expressed in S. clavuligerus NRRL3585 along with the $ermE^*$ promoter. All of them enhanced the production of CA; 2.5-fold overproduction for pIBRHL1, 1.5-fold for pIBRHL2, 1.6-fold for pGIBR, and 1.5-fold for pKS compared to the wild type.

Sequence Variations in the Non-Coding Sequence of CTX Phages in Vibrio cholerae

  • Kim, Eun Jin;Yu, Hyun Jin;Kim, Dong Wook
    • Journal of Microbiology and Biotechnology
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    • v.26 no.8
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    • pp.1473-1480
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    • 2016
  • This study focused on the variations in the non-coding sequences between ctxB and rstR of various CTX phages. The non-coding sequences of CTX-1 and CTX-cla are phage type-specific. The length of the non-coding region of CTX-1 and CTX-cla is 601 and 730 nucleotides, respectively. The non-coding sequence of CTX phage could be divided into three regions. There is a phage type-specific Variable region between two homologous Common regions (Common regions 1 and 2). The non-coding sequence of RS1 element is similar to CTX-1 except that Common region 1 is replaced by a short RS1-specific sequence. The non-coding sequences of CTX-2 and CTX-cla are homologous, indicating the non-coding sequence of CTX-2 is derived from CTX-cla. The non-coding region of CTX-O139 is similar to CTX-cla and CTX-2; however, it contains an extra phage type-specific sequence between Common region 2 and rstR. The variations in the non-coding sequences of CTX phages might be associated with the difference in the replication efficiency and the directionality in the integration into the V. cholerae chromosome.

Effect of Conjugated Linoleic Acid(CLA) on Proliferation and Differentiation of Porcine Adipocyte and Muscle Cell (Conjugated Linoleic Acid(CLA)가 돼지 지방세포와 근육세포의 증식과 분화에 미치는 영향)

  • Chung, C.S.;Kim, H.R.;Kang, J.N.;Kim, N.S.
    • Journal of Animal Science and Technology
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    • v.49 no.1
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    • pp.25-32
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    • 2007
  • The current study was undertaken to determine the effect of conjugated linoleic acid(CLA) isomers, cis-9, cis-11(c9c11), cis-9, trans-11(c9t11), trans-9, trans-11(t9t11), trans-10, cis-12(t10c12) on differentiation of pig preadipocytes and myogenic satellite cells during culture. Cells were isolated from new born pigs. The t10c12 isomer decreased differentiation of pig preadipocytes(92%), but not that of myogenic cells. The t9t11 isomer decreased differentiation of preadipocytes(14%) and increased that of myogenic cells (26%). No other CLA isomers affected differentiation of preadipocytes or myogenic cells. The effects of CLA on proliferation of preadipocytes and myogenic cells were small, compared to the effects on differentiation. These results suggest that CLA isomers have different effects on differentiaton of pig preadipocytes and myogenic cells.

A Simple Method for the Preparation of Highly Pure Conjugated Linoleic Acid(CLA) Synthesized from Safflower Seed Oil

  • Kim, Young R.;Lee, Young H.;Park, Kyung A.;Kim, Jeong O.;Ha, Yeong L.
    • Preventive Nutrition and Food Science
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    • v.5 no.1
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    • pp.10-14
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    • 2000
  • A simple and rapid method was developed to prepare a large quantity of highly pure conjugated linoleic acid (CLA) chemically-synthesized from safflower seed oil (SSO). CLA-SSO(74.9% in purity) was synthesized from fresh SSO(79.9% of linoleic acid) by alkaline isomerization at 18$0^{\circ}C$. Urea(50g) and CLA-SSO (25g) were completely dissolved in ethanol (750ml) using a water bath(5$0^{\circ}C$) and followed by refluxing for 60 min. The resultant was cooled to room temperature and stored in a cold room (4$^{\circ}C$) for 24hrs. After removing the urea adduct by filtration, the filtrate was rotoevaporated under 4$0^{\circ}C$ and the residue was dissolved in hexane (200ml). The hexane extract was washed with distilled water (100ml$\times$3) and dried over sodium sulfate anhydrous. This urea treatment procedure was repeated three times. The purity of CLA recovered from the hexane extract was 95.0%. This method can be applied to prepare a large quantity of highly pure chemically-synthesized CLA (>0.5kg/a batch) from any plant oils containing high percentages (>70%) of linoleic acid.

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Clinical Study of MAST CLA and Sasang Constitution in Allergic Rhinitis Patients (알레르기비염 환자의 체질분포 및 특이적 IgE 측정법(MAST CLA)의 임상적 의의)

  • Kim, Chan-Jung;Kim, Hae-Jung;Kim, Yoon-Bum
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.15 no.2
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    • pp.210-219
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    • 2002
  • Background and Objectives The diagnosis of allergic rhinitis includes detailed clinical history, physical examination and the use of either in vivo or vitro tests for relevant allergens. Skin test has been used the most commonly. Recently MAST CLA is used for determination of serum spcecific IgE, This study attempted to find out the distribution of Sasang Constitution and to compare the MAST CLA with skin tests in allergic rhinitis patients. Methods Skin tests, MAST CLA and Sasang Constitution study were performed for 35 allergic rhinitis patients who visited Kyunghee Oriental Medical Center from Sept. 2001 to Nov. 2001. Results 1. The ratio between male and female was 1:1.5. the peak age was the thirties(42.9$\%$) 2. 45.7$\%$ of patients had family history of allergic diseases and allergic rhinitis was the most common. 3. 51.4$\%$ of patients lived in A.P.T. and in preference of cool and warm, 54.3$\%$ of patients prefered both of cool and warm. 4. Among 24 cases who were consulted to dept. of Sasang, 45.8$\%$ was Taeumin. 5. 65.7$\%$ of patients reacted positive to skin test and the common offending allergen was D. pteronyssinus(82.6$\%$). 6. 25.7$\%$ of patients reacted positive to MAST CLA and the common offending allergen was D. farinae(88.9$\%$). 7. Among 22 cases who was performed skin test and MAST CLA the sensivity and specificity of MAST CLA was 27.4$\%$ and 94.9$\%$. There was significant correlations between MAST CLA and skin test(p=0.005, r=0.574, 1, spearman correlation coefficienct).

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Effects of Conjugated Linoleic Acid and Stearic Acid on Apoptosis of the INS-1 β-cells and Pancreatic Islets Isolated from Zucker Obese (fa/fa) Rats

  • Jang, I.S.;Hwang, D.Y.;Lee, J.E.;Kim, Y.K.;Kang, T.S.;Hwang, J.H.;Lim, C.H.;Chae, K.R.;Jeong, J.H.;Cho, J.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.7
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    • pp.1060-1065
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    • 2003
  • To determine whether dietary fatty acids affect pancreatic $\beta$-cell function, the INS-1 $\beta$-cells and the pancreatic islets isolated from Zucker obese (fa/fa) rats were cultured with stearic acid and conjugated linoleic acid (CLA). As a result, DNA fragmentation laddering was substantially decreased in the INS-1 $\beta$-cells and the isolated pancreatic islets cultured with 2 mM CLA compared to those cultured with stearic acid. To investigate the mechanism by which CLA alleviates cell apoptosis under DNA fragmentation assay, we examined mRNA expressions of apoptosis-related proteins including Bax and Bcl-2 associated with cell death agonist and antagonist, respectively, in both INS-1 cells and islets cultured with 2 mM fatty acids. Bax mRNA expression was not altered by either stearic acid or CLA, whereas Bcl-2 mRNA expression was enhanced by CLA when compared to the stearic acid cultures. However, there were no changes in cell apoptosis and apoptotic-regulating gene products in either INS-1 cells or isolated islets treated with or without 2 mM CLA. It is concluded that CLA maintains $\beta$-cell viability via increased Bcl-2 expression compared to the stearic acid cultures, which may help to alleviate, at least somewhat, the onset of NIDDM in the physiological status. More detailed study is still needed to elucidate the effect of CLA on the prevention of fatty acid-induced $\beta$-cell apoptosis.

Potential Health Benefits of Conjugated Linoleic Acid (CLA): A Review

  • Khanal, R.C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.9
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    • pp.1315-1328
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    • 2004
  • Conjugated linoleic acid (CLA) is a mixture of positional and geometric isomers of octadecadienoic acid with two conjugated double bonds. Of more than a dozen isomers of CLA found naturally in dairy and meat products from ruminants, c-9, t-11 and t-10, c-12 are the two isomers with known physiological importance, including anticarcinogenic, antidiabetic, antilipogenic, and antiatherosclerotic effects. Positive effects of CLA on immune function and bone modeling have also been reported. In spite of the compelling findings in tissue cultures and experimental animal models, its effect, dose, and mechanism of action vis-à-vis specific isomers remains speculative. Results obtained from animal models are inconclusive and conflicting at times in humans, where the research data is limited. It appears that there is a long way to go before CLA could be accepted unequivocally as having definite effects in any or all of these physiological states and how such effects actually occur in humans. The objective of this review is to critically examine the available literature on potential health benefits of CLA observed in cell culture, animal models, and human subjects, wherever possible and to a certain extent the mechanism of action associated with these biological activities.

Production of Conjugated Linoleic Acid by Lactobacillus acidophilus and Their Industrial Application (Lactobacillus acidophilus의 산업적 이용과 CLA 생성)

  • Baick, Seung-Cheon;Chung, Gwan-Seop;Kim, Cheol-Hyeon
    • Journal of Dairy Science and Biotechnology
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    • v.22 no.2
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    • pp.119-130
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    • 2004
  • Application of lactic acid bacteria in the markets are divided into four categories: dairy industry, health food industry, animal feed industry and pharmaceutical industries. Recently, Lactobacillus acidophilus have been used in the food industry and have obtained great attention as key cultures for health benefit. Since commercial application of L. acidophilus has become a common practice, characterization of these cultures were made. Futhermore, the strains selected should produce a final dairy product possessing good taste and acceptable body and texture, a selection step that cannot be achieved unless the product is actually manufactured. Conjugated linoleic acid (CLA) have been recognized as antioxidants, cancer inhibitors, cholesterol depressing agents, and growth promoting factors. Food products from ruminants, particularly dairy products, are the major dietary source of CLA f3r humans. The CLA content in yogurt or cheese can be increased by action of the starter cultures. The finding of the production of CLA by food starter culture opens interesting perspectives far the future in producing fermented products enriched in CLA.

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Effect of Dietary Conjugated Linoleic Acid (CLA) on Abdominal Fat Deposition in Yellow-feather Broiler Chickens and Its Possible Mechanism

  • Zhou, J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.12
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    • pp.1760-1765
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    • 2008
  • A total of 60 one-day-old Yellow-feather broiler chickens were allotted into treatment and control groups. The treatment group was fed with the diet supplemented with 3% conjugated linoleic acid (CLA) for 48 d, while control group was fed with the diet supplemented with 3% rapeseed oil. Chickens were slaughtered in each group at the age of 49 d, and the blood and the abdominal adipose tissue were sampled. Serum cLeptin and serum cAdiponectin were measured by ELISA. The total RNA was extracted from adipose tissue to measure the abundance of the chicken growth hormone receptor (cGHR), insulin-like growth factor 1 (cIGF-1), insulin-like growth factor I receptor (cIGF-IR), peroxisome proliferator-activated receptor gamma ($cPPAR{\gamma}$), cAdiponectin and cAdipoIR mRNA by RT-PCR using ${\beta}$-actin as an internal standard. Results showed that the CLA decreased the abdominal fat index by 20.93% (p<0.05). The level of serum cLeptin but not serum cAdiponectin was significantly increased by CLA treatment (p<0.05). CLA down-regulated the relative abundance of cGH-R mRNA and $cPPAR{\gamma}$ mRNA in abdominal adipose tissue by 24.74% (p<0.05) and 66.52% (p<0.01) respectively. However, no differences were found between CLA treatment group and control group (p>0.05) in the relative abundance of cIGF-1, cIGF-IR, cAdiponectin, and cAdipoIR mRNA in abdominal adipose tissue. The data suggested that CLA inhibited abdominal fat deposition in broiler chicken may be determined by decreasing the GHR available for GH, and by inhibiting the differentiation of preadipocytes via down-regulation of $PPAR{\gamma}$, but independent of IGF and (or) GH-IGF pathway or adiponectin action.

Effect of Monensin and Fish Oil Supplementation on Biohydrogenation and CLA Production by Rumen Bacteria In vitro When Incubated with Safflower Oil

  • Wang, J.H.;Choi, S.H.;Yan, C.G.;Song, M.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.2
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    • pp.221-225
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    • 2005
  • An in vitro study was conducted to examine the effect of monensin or fish oil addition on bio-hydrogenation of $C_{18^-} unsaturated fatty acids and CLA production by mixed ruminal bacteria when incubated with safflower oil. Commercially manufactured concentrate (1%, w/v) with safflower oil (0.2%, w/v) were added to mixed solution (600 ml) of strained rumen fluid and McDougalls artificial saliva (control). Monensin $Rumensin^{(R)}$, 10 ppm, w/v, MO), mixed fish oil (0.02%, w/v, absorbed to 0.2 g alfalfa hay, FO) or similar amounts of monensin and fish oil (MO+FO) to MO and FO was also added into the control solution. All the culture solutions prepared were incubated in the culture jar anaerobically at $39^{\circ}C$ up to 12 h. Higher pH (p<0.047) and ammonia concentration (p<0.042) were observed from the culture solution containing MO at 12 h incubation than those from the culture solutions of control or FO. The MO supplementation increased (p<0.0001-0.007) propionate proportion of culture solution but reduced butyrate proportion at 6 h (p<0.018) and 12 h (p<0.001) of incubations. Supplementation of MO or MO+FO increased (p<0.001) the proportions of $C_{18:2}$. The MO alone reduced (p<0.022-0.025) the proportion of c9,t11-CLA compared to FO in all incubation times. The FO supplementation increased the proportion of c9,t11-CLA. An additive effect of MO to FO in the production of c9,t11-CLA was observed at 6 h incubation. In vitro supplementation of monensin reduced hydrogenation of $C_{18^-}$UFAs while fish oil supplementation increased the production of CLA.