http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Saccharomycopsis속과 Saccharomyces속의 잡종형성 균주에서 생산하는 ${\alpha}$-amylase의 특성
양영기,문명님,임채영,이영하,김정호,Yang, Young-Ki,Moon, Myeng-Nim,Lim, Chae-Young,Rhee, Young-Ha,Kim, Jeong-Ho 한국미생물학회 1999 미생물학회지 Vol.35 No.4
핵전이 방법을 이용하여 효모에서 전분분해능이 향상된 새로운 우수 균주를 개발하고자 하였다. Saccharomycopsis fiburigera KCTC 7393과 Saccharomyces cerevisiae KCTC 7049에서 핵을 분리한 후 영양요구 돌연변이주인 S. cerevisiae의 안으로 전달시켜 잡종(MN-16)을 형성하여 전분 분해능이 증가된 잡종을 선별하였다. 세포 배양액으로 조효소 용액을 만든 후 ammonium sulfate 침전, DEE-Sephacel column chromatography, Sephacryl S-200 column chromatography 등의 정제과정을 통해 9.7%의 회수율로 약 10.6배 정제 된 효소를 얻을 수 있었다. 정제된 효소는 SDS-PAGE 전기영동을 통해 단일 band를 보여 주었으며, SDS-PAGE 와 Sephacryl S-200 column chromatography를 통해서 53kDa으로 나타났다. 정제효소의 최적 활성 온도는 40${\circ}C$이고, 안정성은 40~45${\circ}C$로 나타났다. 최적 활성 pH는 5.5이었고, pH 5.0~7.0 정도에서 pH안정성이 80%정도 유지되었다. 가용성 전분에 대한 $K_{m}$ 값은 2.5㎎/㎖이었다. 또한, 정제 효소의 금속 이온의 효과로 $Ca^{2+}, Co^{2+}, EDTA, Mg^{2+}, Mn^{2+}, Zn^{2+}$ 첨가시 활성이 촉진되었고, $Ca^{2+}$의 경우 가장 높은 반면 $Cu^{2+}, Fe^{2+}, Ni^{2+}$의 경우는 오히려 활성이 감소되었다. This study has been performed to deveope a yeast strain having high ${\alpha}$-amylase production ability using nuclear transfer method. Hybrids formed between the strains of Saccharomyces fiburigera KCTC 7393 and Saccharomyces cerevisiae KCTC 7049 (tyr-, ura-)were obtained by nuclear transfer technique. Nuclei isolated from the wild type S. fiburigera strain were transfered into auxotrophic mutants S. cerevisiae and selected the hybrids showing an increased starch degrading capability were selected (MN-16). This transformant grew best and produced maximal ${\alpha}$-amylase activity on the medium containing 2% (V/V) soluble starch. ${\alpha}$-Amylase from MN-16 was purified electrophoretically homogenety and its properties were investigated. The enzyme was purified about 10.6 fold with an overall yield 9.7% from the culture medium by ammonium sulfate fractionation. DEAE-Sephacel column chromatography, and Sephacryl S-200 column chromatography. The purified enzyme showed a single band on SDS-polyacrylamide gel electrophoresis. The molecular weight of the ${\alpha}$-amylase was estimated to be 53,000 daltons by SDS-PAGE and by gel permeation chromatography on Sephacryl S-200. The purified enzyme showed the maximum activity at pH 5.5 and 40${\circ}C$. The km value for soluble starch was 2.5㎎/㎖. The enzyme activity increased in the presence of $Ca^{2+}, Co^{2+}, EDTA, Mg^{2+}, Mn^{2+}, Zn^{2+}$, but inhibited by $Cu^{2+}, Fe^{2+}$, and $Ni^{2+}$
핵전이에 의한 Aspergillus niger와 Penicillium verruculosum F-3의 속간 잡종형성
양영기,박열,김성준,정현숙,임채영,이영하,Yang, Young-Ki,Park, Yeol,Kim, Sung-Joon,Cheong, Hyeon-Suk,Lim, Chae-Young,Rhee, Young-Ha 한국미생물학회 1993 미생물학회지 Vol.31 No.1
Aspergillus niger 와 Penicillium verruculosum F-3 균주의 돌연변이체 선발은 ultraviolet (UV) 단일처리와 UV 및 N-methyl-N'-nitrosoguanidine(MNNG) 이중처리에 의해 얻었다. 원형질체 형성을 위한 최적조건으로는 pH 5.8, 상투압안정제로는 0.6 M KCI이 최적이었으며, A-niger 와 P. verruculosum 의 재생율은 각각 54.6%, 49.8% 로 나타났다. 핵전이에 의한 형질전환율은 $7{\times}10^{5}~1{\times}10^{5}$ 이었고, 형질전환체의 유전적 안정성은 4.5%~66.5%, conidia 의 크기와 DNA 함량의 측정결과 각각 $2.6{\pm}0.7{\sim}6.5{\pm}0.5{\mu}m$, 5.7~31.3 ${\mu}g/10^{8}$ condia 를 나타내어 aneuploid 로 추측되었다. 모균주와 형질전환체들간의 유전적 안정성과 효소 활성도를 비교하여 선발되 5 균주의 전제 수용성단백질의 전기영동양상은 차이가 있었으며, 동위효소의 양상은 모균주와 유사하지만 CMCase 의 경우 2 균주(TAPW15706, TAPW157-7), $\beta$-glucosidase 의 경우 5균주 (TAPW157-1, TAPW157-4, TAPW 157-5, TAPW157-6, TAPW157-7)에서 band 의 세기가 증가하였음을 관찰할 수 있었다. lntergeneric hybrids formed between Aspergillus niger and Penicillium verruculosum were obtained by nuclear transfer technique. Nuclei isolated from wild type and auxotrophic mutants of donor strains were transferred into the protoplasts of different auxotrophic mutants as recipient strains. Several auxotrophic mutants were isolated from conidiospores of the two strains mutagenized with ultraviolet and N-methyl-N'-nitrosoguanidine. Optimal conditions for formation of intergeneric hybrids were investigated. Frequencies of intergeneric hybrid formation by nuclear transfer were $7{\times}10^{5}~1{\times}10^{5}$. From observations of genetic stability. DNA content. nuclear stain and conidial size. it was suggested that their karyotypes are aneuploid. In addition. the hybrids possess the 1.1~2.3-fold higher cellulase activities than those of parental strains. It was also revealed that some hybrids had different isozyme patterns compared to those of parental strains by CMCase and $\beta$-glucosidase activity assays.
논문 : 응고 ; 불안정 온도구배 하에서 MnBi/Bi공정합금을 일방향응고시 미세조직에 미치는 강화중력의 영향
양영기 ( Young Ki Yang ),황창모 ( Chang Mo Hwang ),강춘식 ( Choon Sik Kang ),이경환 ( Kyong Whoan Lee ) 대한금속재료학회 ( 구 대한금속학회 ) 1998 대한금속·재료학회지 Vol.36 No.7
MnBi Bi eutectic alloy was directionally solidified under enhanced gravity conditions, for a destabilizing thermal gradient, Growth rates were either 1.0cm/h or 1.2cm/h. The thermal gradient applied externally was fixed with 20K/cm under rotational conditions. The experiment shows that the formation of striations can be avoided at certain conditions of net accelerations. This result was discussed in view of the change of critical Rayleigh number, Rac2. To do this, we measured temperature fluctuations in the Bi-melt under similar conditions to growth experiments.
정경훈,양영기,임채영,최형일,허윤희 ( Kyung Hoon Cheong,Young Ki Yang,Chae Young Lim,Hyung Il Choi,Yune Hee Her ) 한국물환경학회 1996 한국물환경학회지 Vol.12 No.1
A laboratory experiments were performed to investigate the effectiveness of pellets formed by Aspergillus niger on the treatment of wastewater containing high concentration of starch and glucose. Pellets were prepared by using pure culture in wheat bran media. The size of pellets formed became small as the pH of medium decrease. In batch experiments, starch was degraded within 0.5 hour and the glucose produced from the starch decomposition was degraded. The glucose production decreased with increasing cell concentration in the range of 5 × 10^5 to 15 × 10^5 spores/㎖. During the continuous experiments, the total COD and starch removal rate were 94% and 100% at the HRT of 12 hours in the fungal pellets reactor conbined with activated sludge reactor when both synthetic and ice cream wastewater were used. The glucose produced from the starch decomposition was degraded to 100% in this system.
Synechocystis sp. PCC 6803의 에너지 대사 결함 돌연변이 균주에서의 Poly(3-hydroxybutyrate) 축적량 증진
김수연,최강국,박연일,박영목,양영기,이영하,Kim Soo-Youn,Choi Gang Guk,Park Youn Il,Park Young Mok,Yang Young Ki,Rhee Young Ha 한국미생물학회 2005 미생물학회지 Vol.41 No.1
본 연구에서는 남세균인 Synechocystis sp. PCC 6803 (Syn6803)을 대상으로 transposable element Tn5를 이용하여 획득된 1,200여 돌연변이주로부터 모균주에 비하여 PHB 축적량이 크게 증진된 균주를 선별하고, Tn5 삽입에 의해 결함을 나타낸 유전자를 확인함으로써 Syn6803에서의 PHB 생합성에 영향을 주는 세포내 생리학적 요인을 조사하고자 하였다. 모균주인 야생형 균주의 경우 질소원이 제한된 $BG11_0$ 배지에서의 PHB 생합성량이 건체량의 $4\%$ (w/w) 수준인데 반하여, $10-34\%$의 생합성량을 보이는 25개의 돌연변이 균주를 얻을 수 있었다. Inverse PCR을 이용하여, 선별된 돌연변이 균주내 돌연변이가 일어난 유전자를 조사한 결과, 아직까지 그 기능이 규명되지 않은 유전자가 대부분이었으나, NADH-ubiquinone oxidoreductase, O-succinylbenzoic-CoA ligase 또는 photosystem II PsbT protein과 같이 광합성과 호흡에 관여하는 유전자에 돌연변이가 일어난 4 균주와 histidine kinase가 결여된 1균주가 확인되었다. 이들 균주를 대상으로pulse-amplitude modulated fluorometer를 이용하여 세포내 $NAD(P)H/NAD(P)^+$비를 측정한 결과, 에너지 대사 흐름의 차단에 의해 세포내의 $NAD(P)HNAD(P)^+$비가 모균주에 비하여 현저하게 높은 것으로 나타났다. 이는 잉여의 전자로 포화된 세포, 즉 NAD(P)H에 의해 환원적 상태를 유지하고 있는 세포의 경우 PHB 축적 이 증진될 수 있음을 시사한다. 이러한 사실은 인위적으로 광합성과 호흡 관련 유전자가 제거되어 $NAD(P)H/NAD(P)^+$비가 높아진 것으로 알려진 다수의 Syn6803 돌연변이 균주들을 대상으로 PHB 생합성량을 조사한 결과로부터 재확인되었다. Photoautotrophic bacteria are promising candidates for the production of poly(3-hydroxybutyrate) (PHB) since they can address the critical problem of substrate costs. In this study, we isolated 25 Tn5-inserted mutants of the Synechocystis sp. PCC 6803 which showed enhanced PHB accumulation compared to the wild-type strain. After 5-days cultivation under nitrogen-limited mixotrophic conditions, the intracellular levels of PHB content in these mutants reached up to $10-30\%$ of dry cell weight (DCW) comparable to $4\%$ of DCW in the wild-type strain. Using the method of inverse PCR, the affected genes of the mutants were mapped on the completely known genome sequence of Synechocystis sp. PCC 6803. As a result, the increased PHB accumulation in 5 mutants were found to be resulted from defects of genes coding for NADH-ubiquinone oxidoreductase, O-succinylbenzoic-CoA ligase, photosystem II PsbT protein or histidine kinase, which are involved in photosystem in thylakoid inner membrane of the cell. The values of $NAD(P)H/NAD(P)^+$ ratio in the cells of these mutants were much higher than that of the wild-type strain as measured by using pulse-amplitude modulated fluorometer, suggesting that PHB synthesis could be enhanced by increasing the level of cellular NAD(P)H which is a limiting substrate for NADPH-dependent acetoacetyl-CoA reductase. From these results, it is likely that NAD(P)H would be a limiting factor for PHB synthesis in Synechocystis sp. PCC 6803.
이정섭,천민석,김옥봉,박종군,김시욱,박열,양영기,홍승환,박상대,Lee, Jung-Sup,Chun, Min-Suck,Kim, Ok-Bong,Park, Jong-Kun,Kim, Si-Wouk,Park, Yeal,Yang, Young-Ki,Hong, Seung-Hwan,Park, Sang-Dai The Korean Society for Integrative Biology 1995 동물학회지 Vol.38 No.4
분열형 호모인 Schizosaccbarornyces pombe에서 RecA 유사 단백질은 hydroxyurea (HU)나 methotrexate (MTX)와 같은 nucleotide pool 형성에 관여하는 효소의 저해제에 의해 유도발현된다. 본 연구에서는 대장균의 RecA 단백질과 S. pombe의 ribonucleotide reductase가 구조적으로 유사한지를 RecA 항체를 이용한 면역침전법과 [5-$^3$H]CDP를 기질로하는 thin layerchromatography방법을 통하여 알아보고자 하였다. S. pombe의 rinonucleotide reductase활성은 100mM HU에 의해 대조군에 비해 26.3% 저해되었으며, RecA 항체를 이용한 면역침전에 의해서도 43.3% 저해되었다. 이와 같은 결과는 S. pombe의 rinonucleotide reductase가 대장균의 RecA 단백질과 구조적으로 유사함을 시사하는 것이다. We have previoosly demonstrated that the RecA-like protein of Schizosaccharomyces pombe (S. pombe) is immunologically related to Escherichia coil (E. coil) RecA protein and that the cellular level of the protein is significantly increased by inhibitors of nucleotide pool-forming enzymes such as hydroxyurea (HU) and methotrexate (MTX) (lee and Park, 1994; lee et al., 1994). In this study, we report that the ribonudeotide redudase activity of S. pombe is inhibited by E. coil RecA antibody, as determined by thin layer chromatography using [5-$^3$H]CDP as a substrate. The relative activity of ribonucleotide reductase was dramatically inhibited by 100 mM of flu (26.4% reduction) in in vitro assay, compared to that of non-treated control. The ribonucleotide reductase activity was also inhibited by immunoprecipitation with E. coil RecA antibody (43.3% reduction). These results indicate that the strudure of S. pombe ribonucleotide reductase is in part similar to that of E. coil RecA protein.