Application of Bacterial Swimming and Chemotaxis for Enhanced Bioremediation

Abstract

Contaminated soil and ground water persistently threatens drinking-water supplies, and is difficult and expensive to remediate. In situ bioremediation is an effective remediation strategy, but is often limited by inadequate distribution of bacteria throughout a contaminated region. Bacterial chemotaxis describes the ability of bacteria to sense chemical concentration gradients in their environment, and preferentially swim toward optimal concentrations of chemicals that are beneficial to their survival. This mechanism may greatly increase the efficiency of ground-water remediation technologies by enhancing bacterial mixing within contaminated zones. Many of the native soil-inhabiting bacteria that degrade common environmental pollutants also exhibit chemotaxis toward these compounds. In this paper, we present a review of bacterial chemotaxis to recalcitrant ground-water contaminants, including relevant techniques for mathematically quantifying chemotaxis, and propose improvements to field-scale bioremediation methods using chemotactic bacteria. By exploiting the degradative and chemotactic properties of bacteria, we can potentially improve both the economics and the efficiency of in situ bioremediation.