Global Warming

The greenhouse effect and global warming are controversial subjects within science. Scientists know that certain gases in the atmosphere hold heat better than others and if these gases increase, then we may see a temperature rise across the planet. This may seem very attractive on a dismal winter morning but would result in the melting of at least some of the polar ice caps and this in turn would lead to a rise in sea level.

As well as the vanishing coastline, warmer temperatures would alter weather systems and could result in the spread of diseases such as malaria. No agreement has been made as to the exact effects but most think that a global rise in temperature would be a bad thing.

So what can bacteria do to prevent this?

As stated earlier, a rise in certain gases is thought to be one of the factors responsible for the greenhouse effect – the main gas is carbon dioxide – pumped out in huge quantities by many industries. Many bacteria need carbon dioxide to perform photosynthesis as plants do, and one (Synechococcus) has been tested in an ingenious system as a carbon dioxide extractor.

Basically, the bacteria are put into a transparent container (as left) and carbon dioxide is bubbled through it. The problem lies with the fact the bacteria need light – those at the top block the light from those lower down and bacteria can only thrive to a certain (shallow) depth.

In a system designed by Matsunaga and Miyachi of the Tokyo university of Agriculture and Technology, special fibre-optic cables that ‘leak’ light along their length are used to carry light from the top throughout the whole container (see right). This means that the bacteria can flourish to a great depth. The greater bacterial population means that correspondingly larger amounts of carbon dioxide can be treated.

The main problem faced is that the bacteria used are killed by very high concentrations of carbon dioxide – it is hoped that this can be solved by genetic engineering using genes from other bacteria that can survive higher amounts of carbon dioxide.

This system has other benefits as well – one being that these bacteria can be used for vitamin production. This means that we can make the process pay for itself – a good incentive for short-sighted industries to actually use it…

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