• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.866-871
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• 2003

Malodorous gas of dimethyl sulfide (DMS) was biologically oxidized to sulfate by Thiobacillus thioparus TK-m (DSM5368) immobilized in/on ceramic beads. More than 99.99％ of DMS removal efficiency was obtained in a ceramic-biofilter reactor of 3.91 when the feed concentrations were about 27.5 and 55.0 mg DMS/1 at $30^{circ}C$. However, the removal efficiency of the biofilter at above $40^{circ}C$ decreased to 4.5 mg DMS/(lㆍmin) which was 85％ of that at $30^{circ}C$.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.485-488
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• 2000

Thiobacillus thioparus TK-m에서 메칠머캅탄(MM) 가스를 기질로 메칠머캅탄 산화효소(MMO)를 유도할 수 있었으며 DEAE-Sephacel과 Superose 12 컬럼 크로마토그래피를 이용하여 정제하였다. 이때 얻어진 각 효소의 비활성은 각각 374과 1240.8 units/mg-protein이었으며 효소의 최적 온도는 $55\;^{circ}C$였다. 상기 정제된 효소액은 SDS-PAGE상에서 66.1 kDa의 분자량을 가지며 20 mM $(NH_4)_2SO_4$ 혹은 200 mM NaCl의 첨가에 대해 최대 활성을 보였다. 글리세린, 에탄올, 아세톤의 첨가에 대해 효소활성은 부분적으로 불활성화되었으며 메탄올에 대해서는 저해받지 않았다. Purpald 발색법을 이용한 흡광도의 변화는 구강내 존재하는 MM 가스로부터 생성될 수 있는 수 십 nmol의 범위의 포름알데하이드에 대해 눈으로 인지가능한 발색시스템에 사용할 수 있음을 확인하였다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권6호
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• pp.375-379
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• 2002

Methyl mercaptan oxidase was successfully induced in Thiobacillus thioparus TK-m using methyl mercaptan gas, and was purified for the detection of mercaptans. The purification procedure Involved a DEAE (diethylaminoethyl) -Sephacel, or Superose 12, column chromatography with recovery yields of 47.5 and 48.5%, and specific activities of 374 and 1240.8 units/mg-protein, respectively, The molecular weight of the purified methyl mercaptan oxidase was 66.1kDa, as determined by SDS-PAGE. The extract, from gel filtration chromatography oxidizes methyl mercaptan, producing formaldehyde, which can be easily detected by the purpald-coloring method. The optimized temperature for activity was found to be at 55$\^{C}$. This enzyme was inhibited by both NH$_4$Cl and (NH$_4$)$_2$SO$_4$, but was unaffected by either KCl or NaCl at less than 200 mM. With K$_2$SO$_4$, the activity decreased at 20 mM, but recovered at 150 mM. In the presence of methanol, full activity was maintained, but decreased in the presence of glycerin, ethanol and acetone 43, 78 and 75%, respectively.