Author(s): Tsibakhashvili NY, Kalabegishvili TL, Rcheulishvili AN, Murusidze IG, Rcheulishvili OA,
Abstract Share this page
Abstract We demonstrated previously that Cr(VI) is readily reduced to oxoCr(V)-diols at the surface of Arthrobacter oxydans-a Gram-positive aerobic bacteria isolated from Columbia basalt rocks originated from a highly contaminated site in the USA. Here, we report an electron spin resonance (ESR) study of Cr(III) hydroxide formation from Cr(V)-diols by this bacterial strain as cells were exposed to 35, 200, and 400 mg/L of Cr(VI) under aerobic conditions as a batch culture and as lyophilized cells. The time-dependent ESR measurements show that the half-time of Cr(III) formation is almost equal to that of Cr(V) decomposition, which is in the range of 3-6 days for all cases. This rate is at least 300 times slower than that of Cr(V) formation. Additionally, atomic absorption spectrometry was also employed to examine the time course of total chromium in bacterial cells. This is the first time the kinetics of Cr(III) complexes formation in bacteria is evaluated.
This article was published in Microb Ecol
and referenced in Journal of Bioremediation & Biodegradation