Raina Margaret Maier
Professor, BIO5 Institute
Professor, Environmental Science
Professor, Pharmaceutical Sciences
Professor, Pharmacology and Toxicology
Primary Department
Department Affiliations
(520) 621-7231
Research Interest
Raina M Maier, PhD, is a Professor of Environmental Microbiology in the Department of Soil, Water and Environmental Science and Director of the University of Arizona NIEHS Superfund Research Program. She also serves as Director of the University of Arizona Center for Environmentally Sustainable Mining and as Deputy Director of the TRIF Water Sustainability Program. Dr. Maier is internationally known for her work on microbial surfactants (biosurfactants) including discovery of a new class of biosurfactants and of novel applications for these unique materials in remediation and green technologies. She is also recognized for her work on the relationships between microbial diversity and ecosystem function in oligotrophic environments such as carbonate caves, the Atacama desert, and mine tailings. Dr. Maier has published over 100 original research papers, authored 23 book chapters, and holds a patent on the use of biosurfactants to control zoosporic plant pathogens. She is the lead author on the textbook “Environmental Microbiology” currently in its second edition.Dr. Maier emphasizes a multidisciplinary approach to her work and has served as PI or co-PI on several large granting efforts including the UA NIEHS Superfund Research Program, the UA NSF Kartchner Caverns Microbial Observatory, and the UA NSF Collaborative Research in Chemistry grant on biosurfactants.


Monica D. Ramirez-Andreotta, ., Mark L. Brusseau, ., Paloma Beamer, ., & Raina M. Maier, . (2013). Home gardening near a mining site in an arsenic-endemic region of Arizona: Assessing arsenic exposure dose and risk via ingestion of home garden vegetables, soils, and water. Science of the Total Environment, 454-455, 373-382.
BIO5 Collaborators
Paloma Beamer, Raina Margaret Maier
Hogan, D. E., Curry, J. E., Pemberton, J. E., & Maier, R. M. (2017). Rhamnolipid biosurfactant complexation of rare earth elements. JOURNAL OF HAZARDOUS MATERIALS, 340, 171-178.
BIO5 Collaborators
Joan E Curry, Raina Margaret Maier
Curry, J., Baughman, K. F., Maier, R. M., Norris, T. A., Beam, B. M., Mudalige, A., Pemberton, J. E., & Curry, J. E. (2010). Evaporative deposition patterns of bacteria from a sessile drop: effect of changes in surface wettability due to exposure to a laboratory atmosphere. Langmuir : the ACS journal of surfaces and colloids, 26(10).
BIO5 Collaborators
Joan E Curry, Raina Margaret Maier

Evaporative deposition from a sessile drop is a simple and appealing way to deposit materials on a surface. In this work, we deposit living, motile colloidal particles (bacteria) on mica from drops of aqueous solution. We show for the first time that it is possible to produce a continuous variation in the deposition pattern from ring deposits to cellular pattern deposits by incremental changes in surface wettability which we achieve by timed exposure of the mica surface to the atmosphere. We show that it is possible to change the contact angle of the drop from less than 5 degrees to near 20 degrees by choice of atmospheric exposure time. This controls the extent of drop spreading, which in turn determines the architecture of the deposition pattern.

Stein, M. M., Hrusch, C. L., Gozdz, J., Igartua, C., Pivniouk, V., Murray, S. E., Ledford, J. G., Marques dos Santos, M., Anderson, R. L., Metwali, N., Neilson, J. W., Maier, R. M., Gilbert, J. A., Holbreich, M., Thorne, P. S., Martinez, F. D., von Mutius, E., Vercelli, D., Ober, C., & Sperling, A. I. (2016). Innate Immunity and Asthma Risk in Amish and Hutterite Farm Children. The New England journal of medicine, 375(5), 411-21.
BIO5 Collaborators
Julie Ledford, Raina Margaret Maier, Fernando Martinez

The Amish and Hutterites are U.S. agricultural populations whose lifestyles are remarkably similar in many respects but whose farming practices, in particular, are distinct; the former follow traditional farming practices whereas the latter use industrialized farming practices. The populations also show striking disparities in the prevalence of asthma, and little is known about the immune responses underlying these disparities.

Maslin, P., & Maier, R. M. (2000). Rhamnolipid-enhanced mineralization of phenanthrene in organic-metal co-contaminated soils. Bioremediation Journal, 4(4), 295-308.


Successful remediation of soils co-contaminated with organics and metals may require a combination of technologies. This research addresses the organic component within co-contaminated sites. It is well known that metal contaminants in soil can partially or completely inhibit normal helerotrophic microbial activity and hence prevent in situ biodegradation of organics. Previous work has shown that a rhamnolipid biosurfactant can complex metals such as lead and cadmium. It has also been demonstrated, in pure culture, that rhamnolipid can mitigate metal inhibition during the degradation of naphthalene. The goal of this study was to investigate whether rhamnolipid could reduce the toxicity of a model metal, cadmium, to indigenous soil populations in two different soils, Brazito and Gila, during the mineralization of phenanthrene. Results show that cadmium inhibited phenanthrene mineralization in both soils at bioavailable cadmium concentrations as low as 27 μM. This inhibition was reduced by the addition of rhamnolipid. Since rhamnolipid is degraded by soil populations, a rhamnolipid pulsing strategy was used to maintain a constant level of rhamnolipid in the system. Using this strategy, phenanthrene mineralization levels comparable to the control (0 mM Cd/0 mM rhamnolipid) were achieved in the presence of toxic cadmium concentrations. This research demonstrates that pulsed application of rhamnolipid may allow bioremedialion of organic contaminants in sites that are co-contaminated with organics and metals.