title: Kinetics and modeling of hexavalent chromium reduction in Enterobacter cloacae.
abstract: Kinetics of bacterial reduction of toxic hexavalent chromium (chromate: CrO(4) (2-)) was investigated using batch and fedbatch cultures of Enterobacter cloacae strain HO1. In fedbatch cultures, the CrO(4) (2-) feed was controlled on the basis of the rate of pH change. This control strategy has proven to be useful for avoiding toxic CrO(4) (2-) overload. A simple mathematical model was developed to describe the bacterial process of CrO(4) (2-) reduction. In this model, two types of bacterial cells were considered: induced, CrO(4) (2-)-resistant cells and uninduced, sensitive ones. Only resistant cells were assumed to be able to reduce CrO(4) (2-). These fundamental ideas were supported by the model predictions which well approximated all experimental data. In a simulation study, the model was also used to optimize fed-batch cultures, instead of lengthy and expensive laboratory experiments.
authors.affiliation: Department of Fermentation Technology, Hiroshima University Higashi-Hiroshima, Hiroshima 724, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
authors.forename: J
authors.initials: J
authors.lastname: Kato
authors.forename: T
authors.initials: T
authors.lastname: Yano
authors.forename: H
authors.initials: H
authors.lastname: Ohtake