• 한국미생물·생명공학회지
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• 제21권6호
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• pp.577-581
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• 1993

The amino acid threonine was produced from glycine and ethanol in a reaction mixture using cell free extract of the methylotrophic bacterium isolated from soil and identified as mellthylo-bacterium sp. KJ29. Although the isolate could grow on carbon source other than methanol, only the cell free extract from the cells grown on methanol produced threonine. Methanol dehydrogenase (MDH) activity was present only in the cells grown on methanol when compared to the cells grown on heterotrophic substrates.

• Journal of Microbiology
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• 제38권4호
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• pp.209-217
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• 2000

Mycobacterium sp. strain JCl DSM 3803 grown in methanol showed no methanol dehydrogenase or oxidase activities found in mast methylotrophic bacteria and yeasts, respectively. Even though the methanol-grown cells exhibited a little methanol-dependent oxidation by cytochrome c-dependent methanol dehydrogenase and alcohol dehydrogenase, they were not the key enzymes responsible for the methanol oxidation of the cells, in that the cells contained no c-type cytochrome and the methanol oxidizing activity from the partially purified alcohol dehydrogenase was too low, respectively. In substrate switching experiments, we found that only a catalase-peroxidase among the three types of catalase found in glucose-grown cells was highly expressed, in the methanol-grown cells and that its activity was relatively high during the exponential growth phase in Mycobacterium sp. JCl. Therefore, we propose that catalase-peroxidase is an essential enzyme responsible for the methanol metabolism directly Of indirectly in Mycobacterium sp. JCl.

• 미생물학회지
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• 제20권4호
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• pp.161-172
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• 1982

In order to compare the metabolic activities of methanol utilizing bacteria, Pseudomonas sp. grown in different carbon sources, changes in respiratory activities, prinicipal enzyme activities for the energy metabolism, and the macromolecular compositions of the cells grown on methanol or glucose were measured. 1. The respiratory activity of cells grown on methanol was higher than that of cells grown on glucose, while glucose exhibited the highest $O_2-consumption$ rate among the different respiratory substrates. 2. TRhe activity of hydroxy pyruvate reductase which participates in serine pathway was high in the cells grown on methanol. However, activities of NAD-linked alcohol dehydrogenase, formaldehyde dehydrogenase and formate dehydrogenase were slightly lower in the cells grown on glucose thant on methanol. 4. For succinic dehydrogenase and malic dehydrogenase which take part in TCA cycle, the specific activities were higher in the cells grown on methanol than in those grown on glucose. No activity of glucose-6-phosphate dehydrogenase, which participates in pentose monophosphate shunt, was detectable in the cells grown on either carbon sources. 5. Protein contents of the cells grown on methanol increased relatively compared with those of the cells grown on glucose. However, there are no changes in the contents of carbohydrate and nucleic acid.

• 미생물학회지
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• 제38권4호
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• pp.209-209
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• 2002

Mycobacterium sp. strain JCl DSM 3803 grown in methanol showed no methanol dehydrogenase or oxidase activities found in mast methylotrophic bacteria and yeasts, respectively. Even though the methanol-grown cells exhibited a little methanol-dependent oxidation by cytochrome c-dependent methanol dehydrogenase and alcohol dehydrogenase, they were not the key enzymes responsible for the methanol oxidation of the cells, in that the cells contained no c-type cytochrome and the methanol oxidizing activity from the partially purified alcohol dehydrogenase was too low, respectively. In substrate switching experiments, we found that only a catalase-peroxidase among the three types of catalase found in glucose-grown cells was highly expressed, in the methanol-grown cells and that its activity was relatively high during the exponential growth phase in Mycobacterium sp. JCl. Therefore, we propose that catalase-peroxidase is an essential enzyme responsible for the methanol metabolism directly Of indirectly in Mycobacterium sp. JCl.

• Journal of Microbiology
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• 제35권1호
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• pp.30-39
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• 1997

Acinetobacter sp. strain JC1 DSM 3803, a carboxydobacterium, was found to grow methylotrophically at the expense of methanol and methlamine, but not of methane, formaldehyde, formate, dimethylamine, or trimethylamine, as the sole source of carbon and energy. The doubling times of the bacterium growing on methanol (0.5%, v/v) and methylamine (0.5%, w/v) at 3$0^{\circ}C$ and pH 6.8 were 4.8 h and 5.7 h, respectively. Cells grown on methanol, however, failed to show typical methanol dehydrogenase and oxidase activities. The cell was found to contain no c-type cytochromes. Cells grown on methanol exhibited higher catalase activity than those grown on pyruvate or glucose. The catalase present in the cells also exhibited peroxidase activity. The catalase activity, growth on methanol of the cell, and oxygen consumption by methanol-grown maldehyde dehydrogenase, formaldehyde reductase, glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase activities were detected from cells grown on methanol.

• 한국미생물·생명공학회지
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• 제25권4호
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• pp.403-407
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• 1997

Medium components for maximum activity of NAD$^{+}$-dependent formate dehydrogenase (EC 1.2.1.2; FDH) were optimized with a methanol-assimilating yeast Hansenula sp. MS-364, preserved by our laboratory. The maximum activity of the enzyme was obtained when the strain was cultivated at 30$circ$C for 24 hours in a medium containing methanol 3%(v/v), yeast extract 0.8%(w/v), K$_{2}$HPO$_{4}$, 0.1%(w/v), KH$_{2}$PO$_{4}$ 0.1%(W/V), MgSO$_{4}$, 7H$_{2}$O 0.05%(w/v), and the pH of the culture broth was adjusted at 5.0.

• KSBB Journal
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• 제11권6호
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• pp.642-648
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• 1996

본 연구에서는 에탄 자화균인 Methylosinus trichosporim OB3b를 이용하여 메탄으로부터 에탄올 생성에 관한 실험을 수행하였다. 에탄으로부터 에탄올을 생성하기 위해서는 메탄 산화과정 중 두번 째 효소인 methanol dehydrogenase 효소의 활성을 부분 저해해야 하므로 이를 위해 EDTA를 사용한 결과 EDTA가 methanol dehydrogenase의 저해제 임을 확인하였고 배지에 6mM EDTA를 첨가하였을 때 전혀 첨가하지 않았을 때와 비교하여 메탄올 생 성이 약 5배 정도 증가되어 lOmmole/L의 에탄율을 얻을 수 있었다. 또한 Cu의 존재유무가 에단올 생성 에 미치는 영향을 실험한 결과 ImM Cu 존재시 $5\mu\textrm{M}$ Cu 존재하에 비해 메탄올 생성이 약 2.5배 증가되어 약 11mmole/L의 메탄올을 얻을 수 있었는데 이는 Cu 존재가 입자상(particulate) MMO의 생성을 촉 진시키며 생성된 이 세포 단위중량당 MMO 활성이 높은 pMMO가 에탄으로부터 에탄올의 생성을 촉진 시키는 것으로 생각된다. 그리고 온도가 에탄올 생 성에 미치는 영향을 실험한 결과 온도가 3TC에서 $30^{\circ}C , 25^{\circ}C$ 로 낮아점에 따라 생성 메단올 농도가 증 가하여 15.5mmole/L에 이르렀고 메탄 소비속도도 증가됨을 알 수 있였다. 또한 메단과 산소의 구생성 분비가 에탄올 생성에 미치는 영향을 실험한 결과 산소대비 에탄 농도가 증가할수록 생성 에탄올의 농 도 및 세포농도가 증가됨을 알 수 였다. 그리하여 50% 메탄, 50% 산소 존재하에 비해 70% 에탄, 30% 산소 경우에는 약 50% 증가된 15.3 mmole/L 농도의 머l단올을 얻을 수가 있였으며 세포농도도 많이 증가됨을 알 수 있다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권2호
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• pp.134-139
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• 2006

Methanotrophs are microorganisms that possess the unique ability to utilize methane as their sole source of carbon and energy. A novel culture system, known as the compulsory circulation diffusion system, was developed for rapid growth of methanotrophic bacteria. Methanol dehydrogenase (MDH, EC 1.1.99.8) from Methylomicrobium sp. HG-1, which belongs to the type I group of methanotrophic bacteria, can catalyze the oxidation of methanol directly into formaldehyde. This enzyme was purified 8-fold to electrophoretic homogeneity by means of a 4 step procedure and was found in the soluble fraction. The relative molecular weight of the native enzyme was estimated by gel filtration to be 120 kDa. The enzyme consisted of two identical dimers which, in turn, consisted of large and small subunits in an ${\alpha}_2{\beta}_2$ conformation. The isoelectric point was 5.4. The enzymatic activity of purified MDH was optimum at pH 9.0 and $60^{\circ}C$, and remained stable at that temperature for 20 min. MDH was able to oxidize primary alcohols from methanol to octanol and formaldehyde.

• Journal of Microbiology and Biotechnology
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• 제26권4호
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• pp.717-724
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• 2016

Methane (CH₄) is the most abundant component in natural gas. To reduce its harmful environmental effect as a greenhouse gas, CH₄ can be utilized as a low-cost feed for the synthesis of methanol by methanotrophs. In this study, several methanotrophs were examined for their ability to produce methanol from CH₄; including Methylocella silvestris, Methylocystis bryophila, Methyloferula stellata, and Methylomonas methanica. Among these methanotrophs, M. bryophila exhibited the highest methanol production. The optimum process parameters aided in significant enhancement of methanol production up to 4.63 mM. Maximum methanol production was observed at pH 6.8, 30℃, 175 rpm, 100 mM phosphate buffer, 50 mM MgCl₂ as a methanol dehydrogenase inhibitor, 50% CH₄ concentration, 24 h of incubation, and 9 mg of dry cell mass ml^-1 inoculum load, respectively. Optimization of the process parameters, screening of methanol dehydrogenase inhibitors, and supplementation with formate resulted in significant improvements in methanol production using M. bryophila. This report suggests, for the first time, the potential of using M. bryophila for industrial methanol production from CH₄.

• 한국미생물·생명공학회지
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• 제27권5호
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• pp.391-398
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• 1999

A methylotrophic actinomycetes strain MO-16, which produce the antimicrobial compound, was isolated from soil and supposed as Amycolatopsis sp. based on taxonomic studies. The cell-free extract of methanol-grown strain MO-16 showed dehydrogenase activity for methanol and formaldehyde when various electron acceptors were added for oxidation. On the other hand, methanol did not affect the production of antimicrobial compounds, and organic nitrogen sources such as corn steep liquor and peptone were better than inorganic nitrogen sources. These compounds showed broad antimicrobial spectrum to the tested strains such as bacteria and yeast. The antimicrobial comounds were very stable under heat(121$^{\circ}C$), acid(pH2.0), alkali(pH11.0) treatments. These compounds were isolated by ethylacetate extract, silica gel column chromatography and reverse phase HPLC. Two compounds(peak 1 and 2) were detected as antimicrobial compounds through the HPLC analysis. The peak 2 was purified as a single compound and revealed a 98% purity.