Our lab studies microbial metabolism with a specific focus on anaerobic processes.  We concentrate on two research themes.  The first involves characterizing pathways for the utilization of diverse electron donors in methanogenic Archaea (methanogens).  Methanogens are responsible for the formation of >95% of Earth’s methane, a potent greenhouse gas, and are essential for the degradation of organic matter in anoxic environments.  Despite decades of study, key details of how methanogens conserve energy and utilize diverse electron donors in metabolism are only beginning to emerge.  The second theme encompasses understanding the redox properties and biochemical reactions of phenazine metabolites.  Phenazines are produced by phylogenetically diverse microorganisms and facilitate many anoxic metabolisms.  For example, phenazines are essential to energy conservation in some methanogens and support anoxic survival of the opportunistic pathogen Pseudomonas aeruginosa.  We are interested in characterizing pathways of phenazine synthesis, modification, degradation, and electron transfer using both genetic and biochemical approaches.

• Costa, Kyle C., Nathaniel R. Glasser, Stuart J. Conway, and Dianne K. Newman (2017) Pyocyanin degradation by a tautomerizing demethylase inhibits Pseudomonas aeruginosa biofilms. Science. 355: 170-173.
• Costa, Kyle C., Megan Bergkessel, Scott Saunders, Jonas Korlach, and Dianne K. Newman (2015) Enzymatic degradation of phenazines can generate energy and protect sensitive organisms from toxicity. mBio. 6: e01520-15.
• Costa, Kyle C. and John A. Leigh (2014) Metabolic versatility in methanogens. Curr Opin Biotechnol. 29: 70-75.
• Costa, Kyle C., Thomas J. Lie, Michael Jacobs, and John A. Leigh (2013) H2-independent growth of hydrogenotrophic methanogen Methanococcus maripaludis. mBio. 4: e00062-13.
• Lie, Thomas J., Kyle C. Costa, Boguslaw Lupa, Suresh Korpole, William B. Whitman, and John A. Leigh (2012) Essential anaplerotic role for the energy converting hydrogenase Eha in hydrogenotrophic methanogenesis. Proc Natl Acad Sci USA. 109: 15473-15478.
• Costa, Kyle C., Phoebe M. Wong, Tiansong Wang, Thomas J. Lie, Jeremy A. Dodsworth, Ingrid Swanson, June A. Burn, Murray Hackett, John A. Leigh (2010) Protein complexing in a methanogen suggests electron bifurcation and electron delivery from formate to heterodisulfide reductase.  Proc Natl Acad Sci USA. 107: 11050-11055.