Zinc effects on a soil bacterial flora characterized by fatty acid composition of the isolates

Summary Effects of zinc (zinc chloride) added to a sandy clay loam soil on its bacterial flora were investigated by the study of cellular fatty acid composition of the isolates. The soil amended with glucose (carbon source) and ammonium sulfate (nitrogen source) was incubated in the presence (1.0 mg/g) or absence of zinc for 96 h. Bacterial strains were isolated on albumin agar from the incubated soils every 24 h. Their cellular fatty acid composition was analyzed and the strains were classified according to the percentage distribution pattern of the fatty acid composition.Two and four dominant patterns of the fatty acid composition were obtained in the isolates from the control soil and the soil with zinc added, respectively. They were different from one another. Most of the dominant strains isolated from the soil with added zinc were zinc-tolerant, and it was suggested that the selection for zinc tolerance readily proceeded.