1. Geomicrobiology Group; College of Life Sciences; University of Dundee; Dundee DD1 5EH Scotland UK
2. Concrete Technology Group; Department of Civil Engineering; University of Dundee; Dundee DD1 4HN Scotland UK
3. Institute of Biological and Environmental Sciences; University of Aberdeen; Aberdeen AB24 3UU Scotland UK
4. Laboratory of Environmental Pollution and Bioremediation; Xinjiang Institute of Ecology and Geography; Chinese Academy of Sciences; Urumqi 830011 China