• Korean Journal of Microbiology
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• v.24 no.3
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• pp.228-235
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• 1986

The aims of the present studies were to develop conditions for the spheroplast formation of Zymomonas mobilis and regeneration of the spheroplasts to normal cells in synthetic media. Z. mobilis cells harvested from exponential growth phase were treated with lysozyme, mutanolysin, and glycine in various conditions. It was found that spheroplasts were formed only with the treatment of glycine but not with the enzymes treatments. It was therefore considered that the tetrapeptide strand of peptide strand of peptidoglycan might play more important roles than the glycan strand in maintaining the vital mechanical function of Z. mobilis. It was found also that removal of outher membrane was the major problem in protoplast formation of Z.mobilis. As results, It was observed that over 85% of cells were readly converted to spheroplasts with sole glycine treatment for 4 hr and 7-10% of the spheroplasts were regenerated to normal cells in synthetic media.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.521.3-522
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• 1986

A gene encoding alcohol dehydrogenase (ADH) in Zymomonas mobilis was cloned into E. coli JM 83 with plasmid pUC 9. The ADH produced by the E. coli transformant was purified bysonication, (NH$^4$)2SO4 fractionation, Affi-Gel blue and hydroxylapatite chromatography. The ADH produced by Z. mobilis was also purified by the same procedures. The two enzyme preparations were characterized and compared. It was found that the E. coli ADH was identical to one of two ADH isozymes of Z. mobilis. Analytical gel filtrations led to the conclusion that the molecule of E. coli ADH was composedv of four subunits having molecular weight of 40,000 (+1,000) dalton each The effect of metal ions on ADH activity and optimum pH were investigated.

• Journal of Microbiology and Biotechnology
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• v.1 no.1
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• pp.12-16
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• 1991

Previously RP1::Tn951 which is a derivative of RP1 containing the lactose transposon Tn951 was introduced into Z. mobilis strain ZM6l00, and RP1::Tn951 was integrated into its genome to yield ZM6306. The galactose operon was incorporated into ZM6306 to yield ZM6307 for more efficient utilization of lactose. Batch culture study has been carried out on Z. mobilis strains, ZM6306 ($lac^+$ ) and ZM6307 ($lac^+$ , $gal^+$ ), which can convert lactose directly to ethanol. Using a medium containing 80 gㆍ$1^{-1}$ glucose and 40 gㆍ$1^{-1}$ lactose, it was found that ZM6306 and ZM6307 produced maximum ethanol concentration of 40 gㆍ$1^{-1}$ and 42 gㆍ$1^{-1}$, respectively, whereas parent strain ZM6 produced 37 gㆍ$1^{-1}$.

• Journal of Microbiology
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• v.33 no.2
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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.

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.977-982
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• 2008

The production of ethanol by microbial fermentation as an alternative energy source has been of interest because of increasing oil price. Saccharomyces cerevisiae and Zymomonas mobilis are two of the most widely used ethanol producers. In this study, characteristics of ethanol fermentation by Saccharomyces cerevisiae CHY1077 and Zymomonas mobilis CHZ2501 was compared. Brown rice, naked barley, and cassava were selected as representatives of the starch-based raw materials commercially available for ethanol production. The volumetric ethanol productivities by Saccharomyces cerevisiae from brown rice, naked barley and cassava were $0.68g/l{\cdot}h$, $1.03g/l{\cdot}h$ and $1.28g/l{\cdot}h$ respectively. But for the Zymomonas mobilis, $2.19g/l{\cdot}h$(brown rice), $2.60g/l{\cdot}h$(naked barley) and $3.12g/l{\cdot}h$(cassava) were obtained. Zymomonas mobilis was more efficient strain for ethanol production than S. cerevisiae.

• Microbiology and Biotechnology Letters
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• v.15 no.5
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• pp.328-333
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• 1987

The stabilities of plasmid vectors in Zymomonas mobilis were tested in batch and continuous cultures. It was found that the growth of the host Zymomonas strain was greatly affected by the size of plasmids as well as the composition of nutrient media： the host cells grew taster when harboring plasmids of smaller sizes and in n non-selective medium. All the Zymomonas plasmid vectors containing antibiotics selective markers and Zymomonas replication origins could be maintained in a stable manner over 30 generations without being integrated into host chromosomes.

• Korean Journal of Microbiology
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• v.25 no.1
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• pp.80-85
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• 1987

The aim of the present studies was to analyze the physiological background of ethanol inhibition in Zumomonas mobilis. The experiments were carried out with a number of continuous culture to give steady state concentration of ethanol. The domposition of fatty acids in the cells obtained from various conditions was analyzed and cell viability was also estimated. As results, it was found that vaccenic acid was the mafor fatty acid in the cell of Z. mobilis and the concentration was changed apparently to increase as increasing the concentration of ethanol produced from substrate utilization. Finally it was observed also that cell viability was decreased remarkably at the elevated ethanol concentration. Those changes might play important roles in the ethanol fermentation to give more complex phenomena observed at high concentration of ethanol.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.708-714
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• 1996

Ethanol production from raw starch was performed using the co-immobilized culture system of Rhizopu japonicus and zymomonas mobilis(R-Z). Glucose Production in immobilized R. japonicus culture was 2-fold higher than that in free cell culture. Ethanol production was 1.67g/L(Yp/s, 0.094) and 6.549/L(Yp/s, 0.38) in R-Z and R-Z 24 culture system, respectively. R-Z system was modified and designated as R-Z 24 system by replacing cotton plug with silicon check valve after 24h fermentation with R-Z system. Optimal substrate concentration for ethanol production in batch culture was 5%(w/v) and ethanol concentration produced was 15.02g/L(Yp/s, 0.36). Ethanol yield(Yp/s, 0.38) in fed-batch culture of 5 times with 2%(w/v) substrate was equal to that in batch culture of 2%(w/v) substrate.

• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.600-605
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• 1989

For the purpose of isolation of the Zymomonas mobilis DNA fragments showing promoter activity in Escherichia coli, a promoter screening vector, PCMT215 was constructed by transferring a promoterless chloramphenicol acetyltransferase (CAT) gene of pYEJ001 into pMT21 which contains $\beta$-lactamase gene and multiple cloning sites. A library of Z, mobilis Sau3AI DNA fragments was constructed in E. coli using the newly constructed pCMT215. Fourteen clones showing resistance to chloramphenicol ranging in concentration from 30 to 750 $\mu$g/$m\ell$ were selected. From five clones of them, the Z. mobilis DNA fragments expressing CAT gene of the recombinant plasmids were sequenced and then sites of transcriptional initiation were identified. The nucleotide sequences of the cloned DNA shared AT rich regions, poly A's or T's stretches and palindromic regions. The positions of transcriptional initiation for CAT gene occurred at more than one site spaced over by 4 to 190 base pairs on the cloned fragments in E. coli.

• Genomics & Informatics
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• v.1 no.1
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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.