Abstract
A new type of sulfite oxidase which utilizes ferric ion (Fe3+) as an electron acceptor was found in iron-grown Thiobacillus ferrooxidans. It was localized in the plasma membrane of the bacterium and had a pH optimum at 6.0. Under aerobic conditions, 1 mol of sulfite was oxidized by the enzyme to produce 1 mol of sulfate. Under anaerobic conditions in the presence of Fe3+, sulfite was oxidized by the enzyme as rapidly as it was under aerobic conditions. In the presence of o-phenanthroline or a chelator for Fe2+, the production of Fe2+ was observed during sulfite oxidation by this enzyme under not only anaerobic conditions but also aerobic conditions. No Fe2+ production was observed in the absence of o-phenanthroline, suggesting that the Fe2+ produced was rapidly reoxidized by molecular oxygen. Neither cytochrome c nor ferricyanide, both of which are electron acceptors for other sulfite oxidases, served as an electron acceptor for the sulfite oxidase of T. ferrooxidans. The enzyme was strongly inhibited by chelating agents for Fe3+. The physiological role of sulfite oxidase in sulfur oxidation of T. ferrooxidans is discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 153-157 |
| Number of pages | 5 |
| Journal | Applied and Environmental Microbiology |
| Volume | 54 |
| Issue number | 1 |
| Publication status | Published - Jan 1988 |
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ASJC Scopus subject areas
- Biotechnology
- Environmental Science(all)
- Microbiology
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Existence of a new type of sulfite oxidase which utilizes ferric ions as an electron acceptor in Thiobacillus ferrooxidans. / Sugio, T.; Katagiri, T.; Moriyama, M.; Zhèn, Y. L.; Inagaki, Kenji; Tano, T.
In: Applied and Environmental Microbiology, Vol. 54, No. 1, 01.1988, p. 153-157.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Existence of a new type of sulfite oxidase which utilizes ferric ions as an electron acceptor in Thiobacillus ferrooxidans.
AU - Sugio, T.
AU - Katagiri, T.
AU - Moriyama, M.
AU - Zhèn, Y. L.
AU - Inagaki, Kenji
AU - Tano, T.
PY - 1988/1
Y1 - 1988/1
N2 - A new type of sulfite oxidase which utilizes ferric ion (Fe3+) as an electron acceptor was found in iron-grown Thiobacillus ferrooxidans. It was localized in the plasma membrane of the bacterium and had a pH optimum at 6.0. Under aerobic conditions, 1 mol of sulfite was oxidized by the enzyme to produce 1 mol of sulfate. Under anaerobic conditions in the presence of Fe3+, sulfite was oxidized by the enzyme as rapidly as it was under aerobic conditions. In the presence of o-phenanthroline or a chelator for Fe2+, the production of Fe2+ was observed during sulfite oxidation by this enzyme under not only anaerobic conditions but also aerobic conditions. No Fe2+ production was observed in the absence of o-phenanthroline, suggesting that the Fe2+ produced was rapidly reoxidized by molecular oxygen. Neither cytochrome c nor ferricyanide, both of which are electron acceptors for other sulfite oxidases, served as an electron acceptor for the sulfite oxidase of T. ferrooxidans. The enzyme was strongly inhibited by chelating agents for Fe3+. The physiological role of sulfite oxidase in sulfur oxidation of T. ferrooxidans is discussed.
AB - A new type of sulfite oxidase which utilizes ferric ion (Fe3+) as an electron acceptor was found in iron-grown Thiobacillus ferrooxidans. It was localized in the plasma membrane of the bacterium and had a pH optimum at 6.0. Under aerobic conditions, 1 mol of sulfite was oxidized by the enzyme to produce 1 mol of sulfate. Under anaerobic conditions in the presence of Fe3+, sulfite was oxidized by the enzyme as rapidly as it was under aerobic conditions. In the presence of o-phenanthroline or a chelator for Fe2+, the production of Fe2+ was observed during sulfite oxidation by this enzyme under not only anaerobic conditions but also aerobic conditions. No Fe2+ production was observed in the absence of o-phenanthroline, suggesting that the Fe2+ produced was rapidly reoxidized by molecular oxygen. Neither cytochrome c nor ferricyanide, both of which are electron acceptors for other sulfite oxidases, served as an electron acceptor for the sulfite oxidase of T. ferrooxidans. The enzyme was strongly inhibited by chelating agents for Fe3+. The physiological role of sulfite oxidase in sulfur oxidation of T. ferrooxidans is discussed.
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UR - http://www.scopus.com/inward/citedby.url?scp=0023716901&partnerID=8YFLogxK
M3 - Article
C2 - 3345075
AN - SCOPUS:0023716901
VL - 54
SP - 153
EP - 157
JO - Applied and Environmental Microbiology
JF - Applied and Environmental Microbiology
SN - 0099-2240
IS - 1
ER -