EN
The effects of Cu on the production of hydroxamate siderophores, microbial activity and physiological state of bacteria in a sandy-loam soil were studied. Soil samples were treated with either 0.5 or 2.5 mg Cu (as chloride) g-1 or were left untreated. Soil microflora responded to added Cu by changing the physiological state and production of specific metabolites, i.e. siderophores; however, microbial activity did not show any significant change.