Our group's focus is on application of physical chemistry in applied microbiology and biotechnology. We address the problems which require more than just microbiology or engineering. Chemistry helps link these two very different areas thus enabling us to solve some difficult real-world problems.

One focus area is the application of immobilized bacteria in gas phase cleanup processes. The principal innovation is the use of fibers as opposed to granules for bacterial immobilization in biofilters – devices for biological air purification. This innovation allowed us to increase up to 90-100% the removal of common organic pollutants, such as ethyl acetate and styrene, from ambient air at low residence times (1-3 s). We also successfully applied similar fiber-based biocatalysts for the removal of airborne inorganic pollutants, such as elemental mercury. The current focus is on the application of specific bacteria to the removal of SO₂ and H₂S from anaerobic gas streams.

The second project started in 1997 after a catastrophic flood occurred in Grand Forks, ND. This flood caused structural, chemical and biological damage to many homes. The current focus is on water-based (and flood damage) mitigation. Studies are being conducted on using bioremediation as a means of removing hydrocarbon contaminants from common building materials such as wood and concrete. Naturally occurring soil bacteria, applied to the surface of hydrocarbon-contaminated materials, remove up to 90-95% of the biodegradable volatile hydrocarbons (such as naphthalene) in 1-4 days.

We are expanding this research area to other pollutants that may contaminate common building materials (such as pesticides, explosives, heavy metals, and radioactive waste). Additionally, we are examining inexpensive chemical alternatives to bioremediation.

One more, unrelated project includes kinetic studies of enzymes and their chemical models. Today, the best chemical catalysts lag way behind enzymes in both activity and specificity. Even though the mechanisms of enzyme-catalyzed reactions have been studied for decades, more understanding of this topic is necessary. Chemical models, including those which we have studied, have shown that enzymes are excellent catalysts not because of their biological nature but because they skillfully apply the combination of standard physico-chemical approaches.

We work with models of the enzymes which catalyze the reactions of oxygenation of organic substrates (cytochrome P-450, etc.). Mechanistic studies of oxidation of thiols with molecular oxygen catalyzed by cobalt tetrasulfophthalocyanine (see the Figure) showed a number of surprising and exciting kinetic and thermodynamic features of this reaction that looks dull and simple. We believe that understanding of the physical chemistry of enzyme catalysis as well as modeling the principles of enzyme catalysis on simple chemical models will result in the mergence of the next generation of chemical catalysts of improved designs which would greatly speed up chemical reactions while decreasing the rate of side product formation.

REPRESENTATIVE PUBLICATIONS

Tyapochkin, E.M. and Kozliak, E.I. “Interactions of Cobalt Tetrasulfophthalocyanine with Thiolate Anions in Dimethylformamide.” Journal of Porphyrins and Phthalocyanines, 2000, 5, 405-414.

Kozliak, E.I., Ostlie-Dunn, T.L., Jacobson, M.L., Mattson, S.R., and Domack, R.T. “Efficient Steady-State Removal from Air by Live Bacteria Immobilized on Fiber Supports.” Bioremediation Journal, 2000, 4, 81-96.

Current, R. W., Kozliak, E. I., and Borgerding, A. J. “Monitoring Biodegradation of VOCs Using High-Speed Gas Chromatography with a Dual-Point Sampling System.” Environ. Sci. & Technol., 2001, 35, 1452-1457.

Beklemishev, M.K. and Kozliak, E.I. “Bioremediation of Concrete Contaminated with n -Hexadecane and Naphthalene.” Acta Biotechnologica, 2003, 23, 197-210.