Ahmedabad: These tiny creatures love heavy metal. It’s not music we mean, but toxic metals like cadmium, mercury, chromium, lead and zinc: stuff that not only cause cancer but also trigger impairments in humans after they seep into our soil and groundwater. A five-year research at the Central University of Gujarat (CUG) has zeroed in on a special group of microbes — mainly bacteria, fungi and actinomycetes — that not only munch on these deadly wastes but also turn the land useful by a process of bio-cleansing.