• 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.

• 미생물학회지
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• 제23권1호
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• pp.56-63
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• 1985

Zymomonas Mobilis로 부터 플라스미드를 분리하여 그 특성을 조사하고 E. col i와 Zymomas양쪽에서 모두 복제하는 셔틀벡터를 제조하였다. Zymomonas mobilis의 4 균주로부터 native plasmid를 분리해 본 결과 모든 Zymomonas균주들은 적어도 하나 이상의 플라스미드를 가지고 있었으며 그 크기는 1.7kb에서 46kb사이였다. 숙주균 주를 선정하고자 Zymomonas의 각종 항생물질에 대한 약재내성을 조사한 결과 특히 tetracycline과 chloramphenic col에 아주 민감한 것으로 나타났다. Zymomonas의 플라스미드들간의 염기배열의 유사성을 조사한 결과 ATCC 1 10988과 ZM 1의 플라스미드들간에는 염기배열의 유사성이 있었고 ZM 4와 Agll은 유사성이 없었다. 클로닝벡터로 개발하고자 하는 ATCC 10988의 1.7kb플라스미드를 pZM886이라 명명하고 이 pZM886을 pBR322와 재조합시켜서 pBZ41이라 명명하였다. pBZ41의 제한효소지도를 작성하였다. pBZ41을 이용하여 조사한 결과 Zymomonas의 replicon은 E.coli에서 작동되지 않았으며 pBR322는 또한 Zymomonas내에서 복제되지 않는 것으로 추정되었다. pBZ41을 conjugal mobilization방법으로 E.coli에서 Zymomonas로 옮겼을 때 Conjugation 된 Zymomonas 들은 모두 tetracycline에 저항성을 나타내었으며 안정하게 플라스미드를 유지시켰다.

• Journal of Microbiology and Biotechnology
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• 제2권2호
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• pp.115-121
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• 1992

In order to broaden the spectrum of substrate utilization of a Gram negative bacterium Zymomonas mobilis which has a great potential as an industrial ethanol producing microorganism, cloning of $\alpha$-amylase gene into Z. mobilis ZM4 was tried. The $\alpha$-amylase gene was isolated from Bacillus stearothermophilus. By Southern blot analysis, it was proven that the $\alpha$-amylase gene fragment was originated from a naturally occuring plasmid of B. stearothermophilus ATCC 31195. To place $\alpha$-amylase gene under the control of Z. mobilis promoter, two different Z. mobilis expression vectors, pZA26 and pLOI204, were used. The truncated $\alpha$-amylase gene was then introduced into these vectors. Both qualitative and quantitative activities of $\alpha$-amylase were observed in Z. mobilis cells harboring these plasmids with the $\alpha$-amylase gene inserted. Gas chromatographic analysis of ethanol showed that one of the Z. mobilis transconjugants was capable of producing 67 mM ethanol from rich medium(RM) containing 5% soluble starch as a sole carbon source.

• Journal of Microbiology and Biotechnology
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• 제13권1호
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• pp.90-98
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• 2003

In vivo $^31p$ Nuclear Magnetic Resonance ($^31p$NMR) and metabolic studies were carried out on an acetic acid tolerant mutant, Zymomonas mobilis $ZM4/Ac^R$, and compared to those of the parent strain, Z. mobilis ZM4, to evaluate possible mechanisms of acetic acid resistance. This investigation was initiated to determine whether or not the mutant strain might be used as a suitable recombinant host far ethanol production from lignocellulose hydrolysates containing various inhibitory compounds. $ZM4/Ac^R$ showed multiple resistance to other lignocellulosic toxic compounds such as syringaldehyde, furfural, hydroxymethyl furfural, vanillin, and vanillic acid. The mutant strain was resistant to higher concentrations of ethanol or lower pH in the presence of sodium acetate, compared to ZM4 which showed more additive inhibition. in vivo $^31p$ NMR studies revealed that intracellular acidification and de-energization were two mechanisms by which acetic acid exerted its inhibitory effect. For $ZM4/Ac^R$, the internal pH and the energy status were less affected by sodium acetate compared to the parent strain. This resistance to pH change and de-energization caused by acetic acid is a possible explanation for the development of resistance by this strain.

• Genomics & Informatics
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• 제2권4호
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• pp.184-190
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• 2004

An approach for genome analysis based on assembly of fragments of DNA from the whole genome can be applied to obtain the complete nucleotide sequence of the genome of Zymomonas mobilis. However, the problem of fragment assembly raise thorny computational issues. Computer simulation studies of sequence assembly usually show some abnormal assemblage of artificial sequences containing repetitive or duplicated regions, and suggest methods to correct those abnormalities. In this paper, we describe five simulation studies which had been performed previous to the actual genome assembly process of Zymomonas mobilis ZM4.

• 한국미생물·생명공학회지
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• 제26권4호
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• pp.309-315
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• 1998

An extracellular levansucrase, which catalyzes the formation of levan from sucrose, from the culture broth of Zymomonas mobilis ZM1 was purified by conventional column purification methods. The final purification yield was 18.3 fold of the crude enzyme from Z. mobilis, with 16.5 % of the enzyme recovered in the preparation step. The molecular weight of the enzyme was estimated to be 91,000 by Superose 12 gel filtration, and 45,000 by SDS-PAGE, indicating that levansucrase is a dimer. The optimum pH for the enzyme activity was around pH 4.0 for sucrose hydrolysis, and was around pH 5.0 for levan formation. The enzyme was inhibited by some metal ions, such as Hg$\^$2+/ and Cu2$\^$2+/, and 50% of inhibition was observed with 5mM EDTA. The enzyme activity was enhanced by the presence of detergent Triton X-100, but inhibited by SDS completely The enzyme catalyzes the liberation of reducing sugars, oligosacccharides and the formation of fructose polymer(levan). The enzyme also catalyzes the transfructosylation reaction of fructose moiety from sucrose to various sugar acceptor molecules, including sugar alcohols.

• 한국미생물·생명공학회지
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• 제15권5호
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• pp.319-327
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• 1987

알코올 생산성이 높은 Zymomonas 균주의 기질 이용성을 넓히기 위한 목적으로 natural replicon을 포함하며 적당한 항생제 저항표지를 갖는 plasmid vector의 제조를 시도하였다. Z. mobilis ATCC10988에서 분리된 몇 개의 plasmid중 3.9kb의 적당한 크기를 갖는 pZM3를 선정하여 수종의 제한효소로 처리하여 절편의 크기에 따라 유전자 지도를 작성하였다. pZM 3의 replicon과 pBR 325의 chloramphenicol 저항유전자를 포함한 재조합 plasmid인 pHZ22를 개발하고 이 plasmid vector가 숙주세포인 Z. mobilis ATCC31821에서 독립적으로 replication됨을 확인하였다. 또 하나의 항생제 저항표지로서 RP4의 tetracycline 저항유전자를 분리하여 pHZ22에 도입함으로써 pHZT224를 제조하였는데 이 plasmid vector도 Zymomonas로 conjugation에 의해 전이되어 안정하게 유지 되었다. 본 연구를 통하여 개발된 plasmid vector는 Z. mobilis와 E. coli에 공히 작용하는 shuttle vector 로서 외부 유전자를 Zymomonas에 도입시킬 수 있는 유용한 유전자 운반체임이 확인되었다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2005년도 International Meeting of the Microbiological Society of Korea
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• pp.85-85
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• 2005

• 한국동물학회:학술대회논문집
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• 한국동물학회 1995년도 한국생물과학협회 학술발표대회
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• pp.94-94
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• 1995

No Abstract, See Full Text

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 1999년도 제39회 춘계학술발표대회
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• pp.47.2-47.2
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• 1999