Distribution of Cu-resistant and Non-resistant Bacteria in Several Cu-contaminated Soils in Japan: Usefulness of the Tolerance Level as an Index of Cu Contamination in Soil

Abstract

Seven Cu-contaminated soils were measured for the number of bacteria grown on agar plates containing various concentrations of Cu, total Cu contents, and DTPA-extractable Cu contents. The relationship between the bacterial number grown on agar plates and concentration of Cu in the agar plates (0-1.5 mM) was well fitted to Duxbury's exponential equation. Total bacterial numbers in the soils positively correlated with the B values in the equation. The B value seemed to be a better index of biotoxic Cu amount in soil than DTPA-extractable Cu of soil. We offer a modification of Duxbury's exponential equation, in which the B value can be estimated once total soil bacterial number was counted. © 1997, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.