Elements

By Christine Ottery

Bees are stayin’ alive

Worker bumblebees normally die in the UK winter, while the queen bees hibernate. However, there has been a remarkable increase in bees spotted in the frosty winter months.

Scientists from Queen Mary, University of London have discovered that this is because a certain type of bee, the buff-tailed bumblebee, can feed on the nectar from exotic plants in public parks and gardens. The winter-flowering plants that have been found to support the buff-tailed bumblebee by the study, published in the journal PLoS One, include strawberry trees and holly-like Mahonia.

Can the shift in behaviour of the buff-tails be attributed to climate change or simply a British love of gardening? Dr Thomas Ings from Queen Mary’s says that it is tempting to link warmer winters and the new winter worker bees, but the crucial factor is the cultivation of exotic winter-flowering plants. For this study, the bees were tagged with minute Radio Frequency Identification chips to monitor their activity.

Dr Ings will be carrying out further research into the reasons for the bees’ behaviour change, including the effect of the cold winter we have had this year.¹

Tree of life

A tree species can help people in the developing world to purify their water cheaply. This could be a life saver for the 1.8 million a year who die from waterborne diseases that cause Diarrhoea, according to the World Health Organisation, 90 per cent of whom are children in developing countries.

The Drumstick tree is endemic to India but also grows in Africa, Central and South America and Southeast Asia. However, the methods for using the trees’ seeds to treat water so it is drinkable are little-known, even where it is cultivated.

Now a review on the use of the Drumstick tree to purify water has been published in Current Protocols in Microbiology, and the process is free to download and share.

The Moringa seed powder, when mixed with water, forms a suspension that causes sediment in the raw water to aggregate into larger particles, which then settle at the bottom of the container. The sediment is then removed, and water is clear and clean. This can reduce bacteria in untreated water by 90 to 99.99 per cent.²

Malaria on the move

Climate change is one of the reasons for the rising incidences of malaria over the past 40 years in the highlands of East Africa.

There had been some conflicting evidence over whether this change was caused by warming. But a new meta-study of over 70 papers published in The Quarterly Review of Biology concluded that the research papers finding climate change to be a cause of the increase in malaria were robust, while the studies showing there was no warming were not statistically strong.

Both the mosquito and the parasite that causes malaria in humans respond to changes in temperature that affect their development and survival. Even a small rise in temperature can cause big increases in the spread of malaria.
The meta-study’s authors from Emory University in Atlanta, US, and Wageningen University in the Netherlands stressed that climate change is only one aspect of a multi-faceted problem. Migration and land-use changes have also encouraged the spread of the deadly disease.

Malaria kills around one million people a year, most often African children.³

Underwater carbon digestion

Scientists at Harvard University have been studying the ocean-dwelling cyanobacteria to find out more about the carbon cycle.

Cyanobacteria are rod-shaped, one-celled organisms that reuse and recycle 40 per cent of carbon in the carbon cycle.

A new study explaining how these tiny but important bacteria “fix”, or digest carbon has been published in Science.
Scientists tagged proteins in the bacteria with fluorescent compounds and could see that cyanobacteria create round structures inside themselves that act as factories turning carbon into sugar and then energy.

The cyanobacteria organise these mini factories spatially, which might have implications for designer bacteria. It could help make more efficient biodiesel-producing bacteria. And the factories, called carboxysomes, could also help engineer bacteria that synthesise hydrogen because they have an outer shell that would protect hydrogen-making enzymes from oxygen, which interferes with the process. Both are carbon-neutral fuels.⁴

1. Stelzer, R., Chittka, L., Carlton, M., & Ings, T. (2010). Winter Active Bumblebees (Bombus terrestris) Achieve High Foraging Rates in Urban Britain PLoS ONE, 5 (3) DOI: 10.1371/journal.pone.0009559 [↩]
2. Michael Lea (2010). Bioremediation of Turbid Surface Water Using Seed Extract from Moringa oleifera Lam. (Drumstick) Tree Wiley InterScience DOI: 10.1002/9780471729259.mc01g02s16 [↩]
3. Chaves, L., & Koenraadt, C. (2010). Climate Change and Highland Malaria: Fresh Air for a Hot Debate The Quarterly Review of Biology, 85 (1), 27-55 DOI: 10.1086/650284 [↩]
4. Savage, D., Afonso, B., Chen, A., & Silver, P. (2010). Spatially Ordered Dynamics of the Bacterial Carbon Fixation Machinery Science, 327 (5970), 1258-1261 DOI: 10.1126/science.1186090 [↩]