IHPH Research Projects
Andrea Holmes, PhD
Professor of Chemistry-Doane University
The Good and the Bad about Biofilms in the Environment
I serve as the Principal investigator of the Center of Undergraduate Research in Biofilms (CURB). Within CURB, I have two major research interests; 1.) Bioremediation of polluted water (the good), 2.) Surface chemistry for biofilm inhibition (the bad).
What are Biofilms and what is their relevance to the environment?
Biofilms are a group of microorganisms in which cells adhere to abiotic or biotic surfaces through extracellular polymeric substances. In medical settings, biofilms are resistant to antibiotics and are a major problem because of hospital acquired infections during surgery and or on artificial implants.1 However, what is less known about biofilms is that they are also very beneficial in environmental bioremediation, such as waste water treatment.2 A recent study in Sweden demonstrated that biofilms that grow in water supplying pipes have the ability to filter out contaminants.3 Since it has been shown that industry and agriculture are major contributors to water pollution,4 biofilms may present an attractive natural alternative for remediation and bio-based water clean-up, especially since pesticides have caused major health impacts in humans.5
Research Question 1: Can biofilms be used for bioremediation of pesticide polluted water?
Pesticides, such thiamethoxam, clothianidin, and atrazine are used in our studies. These pesticides are known to have detrimental effects to human health, and are particularly prevalent in the Midwest.5
The first bacterial species for biofilms that will be used for this study is from the Sphingomonas family which can be can be found in high quality water from pipes that supply housholds.3 This bacterial biofilm can consume non-desirable organic material, toxic chemicals, and various types of plastic.
Research Question 2: Can complex polymeric surface coatings on abiotic surfaces prevent bacterial attachment and biofilm formation?
Marine biofilms adhering to ships and other man-made substrates present a major economic and environmental problem as increased friction leads to increase fuel consumption.6 Currently used antimicrobial coatings, such as tributyltin, are toxic to marine life,7 and therefore is an urgent need for non-toxic chemically modified surfaces.
At Doane, my research evaluates the performance of novel surface coatings to prevent bacterial attachment, inhibit biofilm formation, or significantly modify biofilm growth.
1. Costerton, J. W., Montanaro, L. & Arciola, C. R. Biofilm in implant infections: its production and regulation. Int. J. Artif. Organs 28, 1062–1068 (2005).
2. Amulya, K., Dahiya, S. & Mohan, S. V. Building a bio-based economy through waste remediation: Innovation towards sustainable future. in Bioremediation and Bioeconomy (ed. Prasad, M. N. V.) 497–521 (Elsevier, 2016).
3. Lührig, K. et al. Bacterial Community Analysis of Drinking Water Biofilms in Southern Sweden. Microbes Environ. 30, 99–107 (2015).
4. Moss, B. Water pollution by agriculture. Philos. Trans. R. Soc. B Biol. Sci. 363, 659–666 (2008).
5. Cimino, A. M., Boyles, A. L., Thayer, K. A. & Perry, M. J. Effects of Neonicotinoid Pesticide Exposure on Human Health: A Systematic Review. Environ. Health Perspect. 125, 155–162 (2017).
6. Schultz, M. P., Bendick, J. A., Holm, E. R. & Hertel, W. M. Economic impact of biofouling on a naval surface ship. Biofouling 27, 87–98 (2011).
7. Tornero, V. & Hanke, G. Chemical contaminants entering the marine environment from sea-based sources: A review with a focus on European seas. Mar. Pollut. Bull. 112, 17–38 (2016).
Amanda McKinney, M.D.
Executive Director IHPH