Kyoto University Successfully Engineers Dioxin-Degrading Bacteria

A research group led by Prof. Kosaku Murata at Kyoto University's Graduate School of Agriculture has succeeded in engineering "super bacteria" capable of degrading dioxin two to three times faster than wild-type strains. The research findings were published in the January 16, 2006, issue of the British journal Nature Biotechnology.

Sphingomonas species is able to attract and degrade environmentally hazardous compounds, such as dioxin. Wild-type Sphingomonas sp., however, is generally less capable of degrading these compounds. The degradation capacity of these bacteria had to be increased substantially for use in bioremediation (environmental cleanup and reclamation),.

The researchers identified bacteria with special membrane structures termed 'superchannels', which form pits on the outer membrane. The bacteria open the pits and directly incorporate macromolecules into the cell, as if it opening a mouth to swallow materials in one gulp. The researchers analyzed the molecular mechanisms of pit formation and succeeded in increasing the degradation activity by incorporating pits into the membrane structure of dioxin-degrading bacteria. The engineered bacteria gained stronger resistance to high concentrations of dioxin. Thus, the research group successfully developed a dioxin-degrading "super bacteria" with high bioremediation potential.

In addition to sphingomonas, the molecular engineering technology developed in this study may be applicable to other bacteria species, raising hopes for increased degradation and removal of hazardous substances, including heavy metals.

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Posted: 2006/05/17 03:38:35 PM
Japanese version