Resumen de Microbial communities in four industrial copper dump leaching operations in Bulgaria
The microflora of four industrial copper dump leaching operations in Bulgaria was studied in detail. The microbial communities in these operations had a similar species composition but differed from each other with respect to the counts of microorganism related to the different species. It was found that the copper solubilizalion depended mainly on the amount and activity in situ of the mesophilic acidophilic chemolithotrophic bacteria which occurred in the ore dumps, which were the prevailing microorganisms in these engineered environments. On their parts, this amount and activity depended on a complex of environmental factors. These factors varied in the different dumps as well as in different sections of one and the same dump. The attempts to enhance the leaching by improving some of the environmental factors as well as by introducing laboratory-bred strains into the dumps are described.
