• Title/Summary/Keyword: $L_S$-

Search Result 26,002, Processing Time 0.053 seconds

Identification and Tolerance-Test to Digestive Fluids of Lactobacilli Isolated from Korean Liquid Yogurts (국내 액상발효유에서 분리한 유산균의 동정 및 소화관액 내성조사)

  • So, Myeong-Hwan
    • Korean Journal of Food Science and Technology
    • /
    • v.17 no.3
    • /
    • pp.192-196
    • /
    • 1985
  • Eight strains of Lactobacilli(a, b, b', c, d, e, f and g) were isolated from seven Korean liquid-yogurts(A, B, C, D, E, F and G), and identification and tolerance-test to digestive fluids were carried out. Isolate a from yogurt A and isolate a from yogurt E were identified as L. casei, isolate b from yogurt B as L. acidophilus, isolate d from yogurt D as L. bulgaricus, isolate f from yogurt F as L. helveticus, and isolate b' from yogurt B, isolate c from yogurt C and isolate g from yogurt G as L. jugurti, respectively. Isolate f(L. helveticus) and c(L. jugurti) showed high tolerance to artificial gastric juice but didn't to bile acid. Isolate b(L. acidophilus), a(L. casei), and e(L. casei) showed high tolerance to both artificial gastric juice and bile acid, but isolate d(L. bulgaricus), b'(L. jurgurti) and g(L. jugurti) did not.

  • PDF

Accelerated L5-S1 Segment Degeneration after Spinal Fusion on and above L4-5 : Minimum 4-Year Follow-Up Results

  • Park, Jeong-Yoon;Chin, Dong-Kyu;Cho, Yong-Eun
    • Journal of Korean Neurosurgical Society
    • /
    • v.45 no.2
    • /
    • pp.81-84
    • /
    • 2009
  • Objective : Many biomechanical and clinical studies on adjacent segment degeneration (ASD) have addressed cranial segment. No study has been conducted on caudal segment degeneration after upper segment multiple lumbar fusions. This is a retrospective investigation of the L5-S1 segment after spinal fusion at and above L4-5, which was undertaken to analyze the rate of caudal ASD at L5-S1 after spinal fusion on and above L4-5 and to determine that factors that might have influenced it. Methods : The authors included 67 patients with L4-5, L3-5, or L2-5 posterior fusions. Among these patients, 28 underwent L4-5 fusion, 23 L3-5, and 16 L2-5 fusions. Pre- and postoperative radiographs were analyzed to assess degenerative changes at L5-S1. Also, clinical results after fusion surgery were analyzed. Results : Among the 67 patients, 3 had pseudoarthrosis, and 35 had no evidence of ASD, cranially and caudally. Thirteen patients (19.4%) showed caudal ASD, 23 (34.3%) cranial ASD, and 4 (6.0%) both cranial and caudal ASD. Correlation analysis for caudal ASD at L5-S1 showed that pre-existing L5-S1 degeneration was most strongly correlated. In addition, numbers of fusion segments and age were also found to be correlated. Clinical outcome was not correlated with caudal ASD at L5-S1. Conclusion : If caudal and cranial ASD are considered, the overall occurrence rate of ASD increases to 50%. The incidence rate of caudal ASD at L5-S1 was significantly lower than that of cranial ASD. Furthermore, the occurrence of caudal ASD was found to be significantly correlated with pre-existing disc degeneration.

N,N'-Dimethylethylenediamine-N,N'-di-α-butyric Acid Cobalt(III) Complexes Utilizing Oxidation of Sulfur of S-Methyl-L-cysteine

  • Kim, Hyun-Jin;Youm, Kyoung-Tae;Yang, Jung-Sung;Jun, Moo-Jin
    • Bulletin of the Korean Chemical Society
    • /
    • v.23 no.6
    • /
    • pp.851-856
    • /
    • 2002
  • The Reaction of S-methyl-S-cysteine(L-Smc) with racemic $s-cis-[Co(demba)Cl_2]-1$ (Hydmedba = $NN'-dimethylethylenediamine-NN'-di-\alpha-butyric$, acid) yields ${\Delta}$-s-cis-[Co(dmedba)(L-Smc)] 2 with N, O-chelation. Oxidation of sulfur of 2 with $H_2O_2$ in a 1 : 1 mole ratio gives ${\Delta}$-s-cis[Co(dmedba)(L-S(O)mc)] 3 having an uncoordinated sulfenate group. Oxidation of sulfur of L-Sm with $H_2O_2in$ a 1: 1 mole ratio produces S-methyl-L-cysteinesulfenate (L-S(O)me) 5. Direct reaction of 1 with 5 in basic medium gives an N.O-chelated ${\Delta}$s-cis[Co(dmedba)(L-S(O)mc)-N.O], which turmed out be same as obtained by oxidation of 2, while an N, S-chelated ${\Delta}$-s-cis-[Co(dmedba)(S-S(O)mc)-N,O] complex 4 is obtained in acidic medium from the reaction of 1 with 5. This is one of the rare $[$Co^{III}$(N_2O_2-type$ ligand)(amino acid)] type complex preparations, where the reaction conditions determine which mode of N, O and N, S caelation modes is favored.

EFFECT OF RESIN MONOMERS ON THE ACTIVITY OF CARIOGENIC BACTERIA (수종의 레진 모노머가 우식 유발성 세균의 활성에 미치는 영향)

  • Seo, Young-Ju;Kook, Joong-Ki;Yoon, Jung-Hoon;Kim, Su-Gwan;Lee, Nan-Young;Lee, Sang-Ho
    • Journal of the korean academy of Pediatric Dentistry
    • /
    • v.31 no.2
    • /
    • pp.247-255
    • /
    • 2004
  • The purpose of this study was to examine the effects of resin composite monomers (Bis-GMA, TEGDMA, EGDMA, UDMA, HEMA, Camphorquinone) on the growth of the two cariogenic bacteria, Streptococcus mutans and Streptococcus sobrinus. We obtained the following results : 1. The growth rate of S. mutans and S. sobrinus was decreased significantly in the group of all composite resin monomer at a concentration of 0.03mmo1/L(P<0.01). 2. The growth rate of S. mutars in the group of UDMA at a concentration of 0.01 mmol/L and the group of CQ at a concentration of 0.005 mmol/L, 0.01 mmol/L was decreased significantly compared to the control group(P<0.01). 3. The growth rate of S. sobrinus in the group of HEMA, UDMA at a concentration of 0.01 mmol/L and the group of CQ at a concentration of 0.005mmol/L. 0.01mmo1/L was decreased significantly compared to the control group (P<0.01). 4. The growth rate of S. sobrinus in the group of EGDMA at a concentration of 0.001, 0.01, 0.03mmo1/L was decreased significantly compared to the control group(P<0.01) and were showed to be statistically significant difference between experimental groups(P<0.01).

  • PDF

Antimicrobial Effects of Camellia Japonica L. Leaves Extract on Food-borne Pathogenic Microorganisms (동백나무(Camellia japonica L.) 잎 추출물이 식품유해 미생물에 미치는 항균 효과)

  • Hahn, Young-Sook
    • Korean Journal of Food Science and Technology
    • /
    • v.37 no.1
    • /
    • pp.113-121
    • /
    • 2005
  • Antimicrobial effects of Camellia japonica L. were determined against Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Listeria monocytogenes using paper disc method, and minimum inhibitory concentrations (MICs) were measured. Methanol extract (MEex), water fraction (WAfr), and butanol fraction(BUfr) showed antimicrobial effects against all tested microorganisms, with MEex showing strong antimicrobial effect against S. aureus and L. monocytogenes, and WAfr, Bufr, and ethylacetate fraction (EAfr)against S. aureus. No effects were observed in n-hexane fraction (HEfr) and chloroform fraction (CHfr) against all tested microorganisms. All species grown in the medium adding fractions of Camellia Japonica L. leaves extact were inhibited from WAfr and BUfr, repectively.(meaning not clear) MEex showed over 25% inhibitory effect against all tested microorganisms. BUfr showed over 50% inhibitory effect against all microorganisms except L. monocytogenes. EAfr and WAfr showed over 30% effect against S. aureus and L. monocytogenes. MICs of MEex against S. typhimurium and BUfr against S. aureus were 625 g/mL, indicating C. japonica L. extract can exert antimicrobial activity even at low concentration.

마늘의 저장 및 효소처리 조건에 따른 함황화합물의 변화

  • Sin, Dong-Bin
    • Food preservation and processing industry
    • /
    • v.7 no.1
    • /
    • pp.33-44
    • /
    • 2008
  • 마늘의 저장 중 생리활성과 향미에 중요한 영향을 미치는 성분의 변화를 발표된 논문을 중심으로 정리하여 살펴보았다. 또한 마늘의 냄새를 최소화하고 생리활성을 극대화할 수 있는 기능성식품의 소재개발 타당성을 살펴보기 위하여 열처리(blanching)로 마늘 중의 효소를 모두 불활성화 시킨 후, 이에 마늘로부터 추출한 alliinase를 가하여 반응조건에 따른 alk(en)yl thiosulfinates 생성 및 이들의 분해산물인 휘발성 황함유화합물의 함량변화를 측정하였다. 수확한 마늘의 최종 저장물질로 알려진 -glutamyl-S-alk(en)yl-L-cysteines는 마늘중에 존재하는 -glutamyl-transpeptidase 및 oxidase의 작용에 의하여 감소한 반면 S-alk(en)yl cysteine sulfoxide는 감소한 만큼 증가하였으며, 이는 $-3^{\circ}C$ 및 실온($23^{\circ}C$)에서 보다도 냉장온도($4^{\circ}C$)에서 가장 많이 변화하는 것으로 나타났다. 이러한 감소 및 증가현상은 -glutamyl-S-(2-popenyl)-L-cysteine이 -glutamyl-S-(trans-1-propenyl)-L- cysteine이나 -glutamyl-S-methyl-L-cysteine보다 더 컸다. -glutamyl-S-(2-propen yl)-L-cysteine은 $4^{\circ}C$에서 저장 60일 만에 66%가 감소한 반면 이로부터 생성된 S-(2- popenyl)-L-cysteine sulfoxide는 그 만큼 증가하였다. -glutamyl-S-(trans-1-propenyl)-L-cysteine 및 -glutamyl-S-methyl-L-cysteine도 $4^{\circ}C$에서 150일간 저장한 경우 각각 81% 및 39%가 감소하고, 이들로부터 각각 생성된 S-(trans-1- propenyl)-L-cysteine sulfoxides 및 S-methyl-L-cysteine sulfoxide는 증가하였다. 한편 열처리 마늘에 alliinase를 가하여 함황화합물을 재생성 시킨 결과 8종의 S-alk(en)yl cysteine sulfoxides를 확인할 수 있었다. S-(2-propenyl)-L-cysteine sulfoxide은 전체 thiosulfinates함량의 약 60%를 차지하는 것으로 나타났다. 100, 200, 300 및 400 unit의 alliinase를 첨가하여 15분간 반응시킨 결과 총 thiosulfinates는 생마늘(대조구)에 비하여 각각 37, 68, 77 및 80%가 생성되는 것으로 나타났다. GC/MSD를 이용하여 대조구 및 효소를 첨가하여 반응시킨 시료의 휘발성 향기성분을 분석한 결과 alliinase를 100, 200, 300 및 400 unit 첨가하여 15분간 반응시키면 각각 마늘의 휘발성 향기성분이 25, 36, 66및 76% 씩 재 생성되는 것으로 나타났다. 이상의 결과를 종합해 볼 때 마늘을 이용한 제품개발이나 연구를 할 경우 마늘의 저장조건에 따른 생리활성물질의 분석결과를 근거로 하여 이루어져야 하며, 또한 효소를 이용하여 적절히 반응시키면 마늘 냄새를 $30{\sim}80%$ 범위 내에서 조절이 가능한 것으로 나타났다.

  • PDF

Newly Recorded Naturalized Species in Korea, Silene antirrhina L. (Caryophyllaceae) (한국 미기록 귀화식물: 가는끈끈이장구채(석죽과))

  • Bak, Gyu-Jin;Koh, Jae-Kee;Pak, Jae-Hong
    • Korean Journal of Plant Taxonomy
    • /
    • v.41 no.2
    • /
    • pp.171-174
    • /
    • 2011
  • A naturalized species, Silene antirrhina L is newly reported in Korea. S. antirrhina L. was found along the Geumho riverside in Daegu. S. antirrhina L. is similar to S. koreana Kom. and S. armeria L. in that it has dark glutinous areas. S. antirrhina L. can be distinguished from congeneric species by the stamens and styles of its sepal and seed surface which are finely papillate. The Korean name of S. antirrhina L. "Ganeun-Kkunkkunijangguchea" was newly formulated based on the overall characteristics of this thin and small plant and on the Korean name of S. koreana Kom. photos of the habitat and a description and key of characteristics are provided.

Studies on Cysteine desulfhydrase Produced by Bacteria(Part II) Enzymatic Preparation of L-Cysteine Derivatives by Cysteinedesulfhydrase from Aerobacter aerogenes. (Bacteria가 생산하는 Cysteinedesulfhydrase에 관한 연구(제이보) L-Cysteine 유도체의 효소적 합성에 관하여)

  • 최용진;양한철
    • Microbiology and Biotechnology Letters
    • /
    • v.2 no.1
    • /
    • pp.45-50
    • /
    • 1974
  • 1 With cysteinedesulfhydrase (E. C.4.4.1.1.) from Aerobactor aerogenes, an enzyme which catalyzes the stoichiometric conversion of L-cysteine to pyruvate, ammonia and sulfide, reversibility of the degradation of L-cysteine was investigated. It was found that the enzyme also catalized the reverse reaction of $\alpha$, $\beta$-elimination to synthesize L-cysteine derivatives from pyruvate, ammonia and sulfides when large amounts of substrates were added to the reaction mixtures. 2. The synthetic reaction by cysteinedesulfhydrase proceeded linearly with incubation time and enzyme concentrations. The optimal pH for the synthetic reaction was 10.0. 3. The results of the isolation and identification of the products showed that the L-cysteine derivatives synthesized by this enzymatic method were identical with S-methyl-L-cysteine and S-ethyl-L-cysteine respectively.

  • PDF

Comparative Study on Ethanol Production with Pentose and/or Hexose by Saccharomyces cerevisiae and/or Pichia stipitis (Saccharomyces cerevisiae와 Pichia stipitis를 이용한 오탄당과 육탄당으로부터 에탄올 생산에 관한 비교연구)

  • Kim, Jung-Gon;Ahn, Jung-Hoon
    • Journal of Life Science
    • /
    • v.21 no.3
    • /
    • pp.335-340
    • /
    • 2011
  • Glucose and xylose are the most abundant materials in nature which can be used to produce ethanol by yeast fermentation. Three combinations of cultivation with glucose and xylose were carried out; separated, co-culture, and sequential fermentation with Saccharomyces cerevisiae and Pichia stipitis. In the separated fermentation, S. cerevisiae fermented glucose to produce 14.5 g/l ethanol from 29.4 g/l glucose but hardly used xylose. However, P. stipitis utilized not only glucose but also xylose to produce ethanol 11.9 g/l and 11.6 g/l from 29.4 g/l glucose and 29.0 g/l xylose, respectively. In the mixture of glucose and xylose, P. stipitis fermented both sugars, producing 21.1 g/l ethanol while S. cerevisiae fermented only glucose, producing 13.4 g/l ethanol. In the co-culture and sequential fermentation, the co-culture showed more efficient ethanol productivity with 18.6 g/l ethanol than the sequential fermentation with 12.4 g/l ethanol. To investigate the effect of nutrients in the growth of microorganisms and ethanol production, yeast nitrogen base (YNB) was used in the sequential fermentation with S. cerevisiae and P. stipitis. YNB supplemented some nutrients which S. cerevisiae used up in the broth and the culture showed increased growth rate, increased consumption of xylose, and increased ethanol productivity producing 22.5 g/l ethanol from 54.6 g/l sugar with a yield of 0.41 g/g.

SUMMING AND DOMINATED OPERATORS ON A CARTESIAN PRODUCT OF c0 (𝓧) SPACES

  • Badea, Gabriela;Popa, Dumitru
    • Journal of the Korean Mathematical Society
    • /
    • v.54 no.3
    • /
    • pp.967-986
    • /
    • 2017
  • We give the necessary condition for an operator defined on a cartesian product of $c_0(\mathcal{X})$ spaces to be summing or dominated and we show that for the multiplication operators this condition is also sufficient. By using these results, we show that ${\Pi}_s(c_0,{\ldots},c_0;c_0)$ contains a copy of $l_s(l^m_2{\mid}m{\in}\mathbb{N})$ for s > 2 or a copy of $1_s(l^m_1{\mid}{\in}\mathbb{N})$, for any $l{\leq}S$ < ${\infty}$. Also ${\Delta}_{s_1,{\ldots},s_n}(c_0,{\ldots},c_0;c_0)$ contains a copy of $l_{{\upsilon}_n(s_1,{\ldots},s_n)}$ if ${\upsilon}_n(s_1,{\ldots},s_n){\leq}2$ or a copy of $l_{{\upsilon}_n(s_1,{\ldots},s_n)}(l^m_2{\mid}m{\in}\mathbb{N})$ if 2 < ${\upsilon}_n(s_1,{\ldots},s_n)$, where ${\frac{1}{{\upsilon}_n(s_1,{\ldots},s_n})}={\frac{1}{s_1}}+{\cdots}+{\frac{1}{s_n}}$. We find also the necessary and sufficient conditions for bilinear operators induced by some method of summability to be 1-summing or 2-dominated.