Metal Sequestering by Microorganisms in and from Aquatic Environments

9313317 Corpe This is an award to provide renewed support for a project the objective of which is to characterize the sequestering effect of polyphosphate bodies in picoplankton populations of aquatic environments. In previous research supported under NSF Grant No. 91-17165, the investigators developed an analytical technique involving x-ray dispersive analysis in conjunction with use of electron microscopy to study the elemental composition of individual cells and their intracellular components. In this renewal project, the investigator will focus on the various mechanisms by which trace and heavy metals are taken up and immobilized within the microbial consortium that makes up natural aquatic environments. The work is expected to result in the isolation of numerically important, metal immobilizing species from sediments contaminated by heavy metals and determination of their propensity for metal uptake. The role of microorganisms in the environmental cycling of metals is of importance in bioleaching, biosorption and related bioprocessing of municipal and industrial wastewaters. Metals are also present in sediments of streams, ponds, lakes and estuaries where they can adversely affect water quality. Results of this research may be applied to modeling the diffusion, dispersion and interactions of heavy metals of significance in affecting the quality of environmental waters and in design of processes and systems to decontaminate sediments and soil. ***