• 미생물학회지
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• 제24권3호
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• pp.228-235
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• 1986

Zymomonas mobilis의 spheroplast 형성과 새생조건의 새량과 초|소배시에서의 새생에 대해서 연구하였다. Tris-maleate buffer (pH 5~6), $Ca^{++}$ ions 그러고 EDTA등은 out야 membrane의 투과성 변화를 야기시 켰다 Zymommonas의 세포벽은 lysozyme, mutanolysin같은 세포벽 분해효소에 의해 분해가 되지 않은 것처럼 보였고 sphe-roplast 생성에 glycine 처리는 필수적이었다. 그러나 lysozyme 처리에 의해서 spheroplast 형성이 촉진되는 것을 확인하였다. 따라서 ly sozyme과 glycine을 함께 처리함으로서 spheroplasting배지에서의 처리시간을 4시간으로 단축 할 수 있었고 재생율이 7-10% 증가되었다.

• Journal of Microbiology
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• 제33권2호
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• pp.126-127
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• 1995

A Zymomonas mobilis DNA fragment consisting of 207 nucleotides, which corresponded to the 5'-flanking region of an adhB gene encoding alcohol dehydrogenase II, was fused to the structural gene coding for a Bacillus endo-.betha.--1, 4-glucanase. The Z. mobilis DNA framgment waw identified to promote 50-fold increase in the expression of endo-.betha.1. 4 glucanase gene in Escherichia coli.

• 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.

• Journal of Microbiology and Biotechnology
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• 제19권7호
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• pp.666-674
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• 2009

An electrochemical bioreactor (ECB) composed of a cathode compartment and an air anode was used in this study to characterize the ethanol fermentation of Zymomonas mobilis. The cathode and air anode were constructed of modified graphite felt with neutral red (NR) and a modified porous carbon plate with cellulose acetate and porous ceramic membrane, respectively. The air anode operates as a catalyst to generate protons and electrons from water. The growth and ethanol production of Z. mobilis were 50% higher in the ECB than were observed under anoxic nitrogen conditions. Ethanol production by growing cells and the crude enzyme of Z. mobilis were significantly lower under aerobic conditions than under other conditions. The growing cells and crude enzyme of Z. mobilis did not catalyze ethanol production from pyruvate and acetaldehyde. The membrane fraction of crude enzyme catalyzed ethanol production from glucose, but the soluble fraction did not. NADH was oxidized to $NAD^+$in association with $H_2O_2$reduction, via the catalysis of crude enzyme. Our results suggested that NADH/$NAD^+$balance may be a critical factor for ethanol production from glucose in the metabolism of Z. mobilis, and that the metabolic activity of both growing cells and crude enzyme for ethanol fermentation may be induced in the presence of glucose.

• 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.

• Korean Chemical Engineering Research
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• 제46권5호
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• pp.977-982
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• 2008

유가의 급등과 화석 연료의 고갈, 환경 오염문제 등에 대비하기 위하여 대체 수송 연료로서의 바이오에탄올에 대한 관심이 고조되고 있으며, 이에 따라 바이오에탄올 생산비용 절감을 위한 연구가 매우 활발하다. 본 연구에서는 에탄올 생산성 향상을 위하여 Zymomonas mobilis의 에탄올 발효특성을 Saccharomyces cerevisiae와 비교하였다. 음료용 에탄올 생산균주로 오랫동안 사용되어 온 효모와 연료용 에탄올 생산균주로서의 Z. mobilis의 가능성을 검토한 바 최종 에탄올 생성 농도는 큰 차이가 없었으나, 에탄올 생성속도는 Z. mobilis가 S. cerevisiae에 비해 2배 이상 빨랐다. 에탄올 생산성을 비교해 보면 현미, 쌀보리, 카사바의 경우 Z. mobilis는 $2.19g/l{\cdot}h$, $2.60g/l{\cdot}h$, $3.12g/l{\cdot}h$인 반면 S. cerevisiae는 $0.68g/l{\cdot}h$, $1.03g/l{\cdot}h$, $1.28g/l{\cdot}h$ 이었다. 증류액 내의 불순물은 S. cerevisiae는 iso-amylalcohol이 Z. mobilis는 ethyl heptanoate 농도가 상대적으로 높았다.

• Genomics & Informatics
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• 제1권1호
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• pp.55-60
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• 2003

The nucleotide sequence of pZMO1, a small cryptic plasmid of Zymomonas mobilis ATCC10988 was determined. Analysis of 1,680 bp of sequence revealed $69\%$ identity with Shigella sonnei plasmid, pKYM and $61\%$ identity with Nostoc sp. ss DNA replicating plasmid. Analysis of a deduced amino acid sequence of an orf of pZMO1 revealed $75\%$ identity and $90\%$ similarity with the repA gene of Synechocystis sp. plasmid pCA2.4. The upstream region of the repA gene of pZMO1 possesses six directed repeat sequences and two inverted repeat sequences at downstream of the IR consensus sequence of nick region of rolling circle replication (RCR) plasmid. A typical terminator hairpin structure was found at the downstream region of repA gene. Degradation of single-stranded plasmid DNA by S1 nuclease was detected by Southern hybridization. It suggests that pZMO1 replicates by a rolling circle mechanism in Z. mobilis ATCC10988 cells.

• 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.

• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.94-100
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• 2010

Zymomonas mobilis was immobilized in a modified graphite felt cathode with neutral red (NR-cathode) and Saccharomyces cerevisiae was cultivated on a platinum plate anode. An electrochemical redox reaction was induced by 3 volts of electric potential charged to the cathode and anode. The Z. mobilis produced 1.3-1.5 M of ethanol in the cathode compartment, whereas the S. cerevisiae produced 1.7-1.9 M in the anode compartment after 96 h. The ethanol produced by the Z. mobilis immobilized in the NR-cathode and S. cerevisiae cultivated on the platinum plate was 1.5-1.6 times higher than that produced under conventional conditions. The electrochemical oxidation potential inhibited Z. mobilis, but activated S. cerevisiae. The SDS-PAGE pattern of the total soluble proteins extracted from the Z. mobilis cultivated under the electrochemical oxidation conditions was gradually simplified in proportion to the potential intensity. Z. mobilis and S. cerevisiae were cultivated in the cathode and anode compartments, respectively, of an electrochemical redox combination system. The Z. mobilis culture cultivated in the cathode compartment for 24 h was continuously transferred to the S. cerevisiae culture in the anode compartment at a rate of 300 ml/day. Approx. 1.0-1.2 M of ethanol was produced by the Z. mobilis in the cathode compartment within 24 h, and an additional 0.8-0.9 M produced by the S. cerevisiae in the anode compartment within another 24 h. Thus, a total of 2.0-2.1 M of ethanol was produced by the electrochemical redox combination of Z. mobilis and S. cerevisiae within 48 h.

• KSBB Journal
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• 제26권3호
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• pp.243-247
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• 2011

Using Bacillus subtilis spore display system, with cotG as an anchoring motif, levansucrase from Zymomonas mobilis, was displayed on the outer surface of Bacillus subtilis spore. Flow cytometry of DB104 (pSDJH-cotG-levU) spore, proved the surface localization of CotG-LevU fusion protein on the spore compared to that of DB104. Enzymatic activity of DB104 (pSDJH-cotG-levU) spore showed more than 1.5 times higher levansucrase specific activity compared to that of the host spore, which is a remarkable increase of enzymatic activity considering the existence of sacA (sucrase) and sacB (levansucrase) in the Bacillus subtilis chromosome. The spore integrity, revealed by sporulation frequency test after heat and lysozyme treatment of spore, did not changed at all in spite of the CotG-LevU fusion protein incorporation into the spore coat layer during spore formation process. These data prove again that Bacillus subtilis spore could be considered as good live immobilization vehicle for efficient bioconversion process.