Research topics and themes

Organic matter processing in wetlands: Microbial extracellular enzyme activity can be linked to the decomposition of organic matter. We're developing enzymatic models to predict decomposition rates for fine particulate organic matter (FPOM) in sediments around Lake Pontchartrain, Louisiana, and hoping to map out areas that are likely to show organic matter loss or accrual. This is potentially important to efforts to understand and predict areas of land loss and coastal erosion, particularly as these systems become more vulnerable to major storms and hurricanes. We're also using molecular techniques to determine the composition of microbial communities associated with FPOM in these wetlands.

Spatial patterns in microbial community structure and function: While humans tend to sample on scales that are convenient for us, microorganisms don't necessarily follow that pattern. We've been developing and using geostatistical techniques to examine fine-scale spatial heterogeneity in microbial processes (primarily extracellular enzyme activity) in soils and other systems. This area of research is essentially landscape ecology, but our landscapes may be no more than a few cm across.

Bacterial succession and biofilm development: When surfaces are immersed in liquids they are rapidly colonized by bacterial populations (biofilms), and these populations are replaced over time in a process that resembles ecological succession. We can use molecular techniques such as denaturing gradient gel electrophoresis (DGGE) to study these changes, and determine patterns in species diversity as the community develops. This is an ongoing area of research that links microbiology and microbial ecology to ideas from theoretical community ecology.

The influence of rainfall and weather events on microbial communities: Very few studies have examined the influence of weather events such as rainfall on ecological systems. The reason is obvious - we don't like to sample mud or soil in the middle of a rainstorm! We've recently examined how rainfall changes both the activity and structure of bacterial communities associated with the phyllosphere, and we're also studying the influence of rainfall on microbial processes in soils.

Arsenic microbiology: While arsenic is toxic to many organisms, a large number of bacteria have genetic mechanisms to resist arsenic. These bacteria are much more common than is generally known, and we've been able to isolate arsenic-resistant bacteria from various aquatic and terrestrial environments. Other research has used bioinformatic techniques to examine the phylogeny of arsenic resistance genes.

Website maintained by Colin Jackson. Last updated 4/7/08. Email questions and comments to cjackson@olemiss.edu