WRRC Water Quality Research Laboratory
Jean E. McLain
Work in the McLain laboratory takes place at the interface of water microbiology, soil science, and ecosystem ecology, studying the processes controlling the response of soil and water bacteria to anthropogenic and natural stressors. The research is by nature highly applied, designed to tackle the challenges of soil and water sustainability in a world experiencing population growth and global climate change.
A major theme of current research is the study of anthropogenic effects on the development of bacterial antibiotic resistance in soil and water. Following their use for control of human disease and/or animal husbandry, it is estimated that up to 75% of antibiotics are excreted in urine and feces unaltered or as potentially bio-active metabolites. Many wastewater treatment plants are not designed for the removal of organic pollutants and as a result, residual antibiotics are released into the environment with treated wastewater, leading to concerns regarding their contribution to resistance in soil and water microorganisms.
Students in the McLain laboratory focus on key questions, including:
- Are the antibiotic concentrations sufficient to induce selective enrichment of resistant populations?
- Or do these trace antibiotics simply serve as a carbon-rich energy source for microbial metabolism?
- and Which resistance genes should we monitor in soil and water?
- Is the presence of genes alone meaningful, given that wastewater treatment processes are designed to destroy bacterial membranes and release DNA?
- Does the presence of resistance genes correspond to the number of living resistant bacteria?
Work in the McLain lab has also focused on understanding the unique biological and chemical qualities of recycled municipal wastewater, using molecular and cultural methods to study a range of bacterial groups in recycled water and irrigated soils. This work has identified points within water distribution systems where degradation in microbiological water quality occurs, providing utility operators with information to be used in efficient placement of in-line chlorine boosters.
We often have openings for graduate and undergraduate students. If you have strong experimental skills, breadth and depth in soil and water science, extensive experience, and creative research ideas, please contact Jean McLain at mclainj@email.arizona.edu.