Innoculated plants perform better at bio-remediation

Giving plants 'jabs' to protect them against the ill effects of pollution can make them better at cleaning up contaminated land, say researchers in Ireland.

Using plants to clean up toxic soils is nothing new, but scientists based in Ireland are working on plans to marry bioremediation with the production of biodiesel, arguably killing two birds with one stone.

Bioremediation is often used as a cheap, environmentally sensitive way of removing heavy metals such as arsenic, copper, zinc, chromium and lead from contaminated land but it can be a slow process as successive crops need to be grown on the affected site.

Now scientists from Institute of Technology, Carlow, Ireland have come up with possible solution by effectively inoculating plants against the worst effects of the pollution.

They have combined bacteria resistant to heavy metals with fuel crops such as oil seed rape.

“We discovered that inoculating the plants with metal resistant bacteria provided them with sufficient protection that their seeds germinated better and their growth was enhanced,” said researcher Olivia Odhiambo.

“The plant leaves accumulate the metals, the bacteria deal with the contamination, and the plants seem to benefit from some of their activity.

“As some of the bacterial strains we tested are showing enhanced growth properties in the crop, this also means greater plant production and more biodiesel.

“This is good news for owners of land that cannot currently be used for food plants due to heavy metal contamination. However, this technology could also have much wider implications in improving biofuel crop production nationally and internationally by simply helping farmers grow more fuel per hectare.”

There is a potential catch to the scheme, however.

Using food crops to absorb toxins from contaminated soils is best avoided, for obvious reasons, but it might be possible that biofuel crops which have soaked up the heavy metals might produce a dirtier fuel than those produced on green field sites.

Ms Odhiambo was not available to discuss this possible problem at the time of publication, but a spokesman told edie the scientists were aware of the issue and more research was needed in this area .

Sam Bond

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