Team:Tokyo Tech/Iron-oxidizing bacteria

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Safety

Achievement

We cultured iron-oxidizing bacteria (Acidithiobacillus ferrooidans).

Introduciton ~Why do we need to use Iron-oxidizing bacteria for terraforming of Mars?~

Heterotrophic bacteria cannot live in native Martian environment because there are no organic matters on Mars, however autotrophic bacteria can live without organic matters. Iron-oxidizing bacteria is autotrophic bacteria. Iron-oxidizing bacteria gets energy by oxidizing Fe(Ⅱ). To grow on Mars, iron-oxidizing bacteria require only energy injection of us because of composition of the Martian surface, crust and atmosphere. (リンク) We propose culturing iron-oxidizing bacteria on Mars and producing organic matters. Accumulation of organic matters provides habitable environment for heterotrophic bacteria (for instance, E.coli).

Material and method

Iron-oxidizing bacteria

Iron-oxidizing bacterium is a kind of autotrophic bacteria.
Iron-oxidizing bacteria reduce NAD⁺ to NADH by oxidizing Fe(Ⅱ). Iron-oxidizing bacteria grow with dissolved CO₂ as carbon source, not organic matters. In laboratory, iron-oxidizing bacteria are cultured in 9K medium which contains Fe(Ⅱ) and no organic matters.

Preparation of 9K medium (for iron-oxidizing bacteria)

Prepare following A&B solution.

A Solution

B Solution

Sterilize A solution by autoclaving.
Sterilize B solution by using filter.
Mix A&B solution before use.
A solution can be stored for 2 weeks.

Cultivation of Acidithiobacillus ferrooxidans

We cultured Acidithiobacillus ferrooxidans (iron-oxidizing bacteria). The medium for A.ferrooxidans was blue before cultivation owing to Fe(Ⅱ). The presence of A.ferrooxidans changed the medium into brown one after culturing for two days. This change was observed owing to the production of Fe(OH)₃. We confirmed the growth by using microscope of 200 magnifications.

Result

Discussion

Reference

MEDIA FOORMULATIONS http://wdcm.nig.ac.jp/catalogue/ncim/document/Ncim_media.pdf

@@ Line 18: / Line 18: @@
 ===Iron-oxidizing bacteria===
-Iron-oxidizing bacterium is a kind of autotrophic bacteria.
+Iron-oxidizing bacterium is a kind of autotrophic bacteria.<br\>
 Iron-oxidizing bacteria reduce NAD<sup>+</sup> to NADH by oxidizing Fe(Ⅱ).
 Iron-oxidizing bacteria grow with dissolved CO<sub>2</sub> as carbon source, not organic matters.