Where there's muck there's a doctorate

Peter Stenbro-Olsen is enjoying the sweet smell of success after being awarded the country's first doctorate in composting.

According to the Dundee City Council composting officer, who began his part-time PhD at the University of Abertay Dundee in 1992, composting has a 4,000-year pedigree, but really began to develop in the United Kingdom in the 1950s, only to be stifled within decades by the throwaway society. However, recent legislative changes have boosted recycling, he said, as people try to avoid impending landfill taxes and the costs and pollution of incineration.

"Composting has been more an art than a science," Dr Stenbro-Olsen said. "I've tried to bring science in so that we can do it a bit more efficiently and effectively."

A garden compost heap normally takes a year to become usable, Dr Stenbro-Olsen said. But Dundee has speeded the process using heat.

This would normally be seen as unworkable because temperatures above 40oC kill the bacteria responsible for the composting process. Dr Stenbro-Olsen, however, has identified previously undiscovered bacteria, which he describes as "a large heat-loving thermophile that appears to be responsible for most high-temperature composting".

These populations of micro-organisms increase at high temperatures rather than declining, feeding off the bacteria that have been killed by the heat and the composting they had already done.