Isolation of Potassium Chromate-tolerant Bacterium and Chromate Uptake by the Bacterium

Abstract

A potassium chromate-tolerant bacterium was isolated from activated sludge, and the bacterium was identified as Pseudomonas ambigua G-1. The bacterium tolerated up to 2000ppm of Cr⁶⁺, 1700ppm of Cu²⁺ and 200ppm of Cd²⁺, but did not tolerate Hg²⁺. Chemical analysis indicated 86.5% uptake in the soluble fraction and 13.5% uptake in the insoluble fraction of cells. Chromate uptake distribution in the soluble fraction indicated 28.9 in microsomal fraction and 78.1% in supernatant fraction, Chromate distribution in the insoluble fraction showed 61% in lipid-fraction and 21% in polyphosphate-polysaccharide-fraction. Chromate inhibited the syntheses of protein, DNA in soluble fraction and RNA in microsomal fraction.