Daniel A. Kunz. Microbial Physiology and Biochemistry 

Cyanide is a notorious poison that arises naturally and from various industrial practices. Our work focuses on the metabolism of cyanide by bacteria. Recent work has shown that cyanide is readily assimilated as a sole nutritional nitrogen source. In one organism, Pseudomonas fluorescens strain NCIMB 11764, a novel enzyme, cyanide oxygenase, is responsible for initiating cyanide conversion generating ammonia and carbon dioxide as ultimate metabolic products. Current work in our laboratory is focused on the isolation and characterization of this enzyme with the long term goal being the delineation of the complete metabolic pathway for cyanide dissimilation. The role of keto acids in conferring cyanide tolerance is also being investigated since recent studies have shown that the excretion of such compounds may serve to detoxify cyanide prior to further enzymatic metabolism. Other interests of our laboratory are related to the biodegradation of natural and xenobiotic chemicals and the evolution of metabolic diversity as it relates to microbial ecology. Students in our laboratory are exposed to various research techniques including, growth and enrichment of metabolically diverse bacteria, chemical identification of enzymatic metabolites, enzyme purification, and gene cloning technology.

Kunz, D. A., J-L. Chen and G. Pan. 1998. Accumulation of alpha-keto acids as essential components in cyanide assimilation by Pseudomonas fluorescens NCIMB 11764. Appl. Environ. Microbiol. 64:4452-4459.

Chen, J-L., and D. A. Kunz. 1997. Cyanide utilization in Pseudomonas fluorescens NCIMB 11764 involves a putative siderophore. FEMS Microbiol. Lett. 156:61-67.

Wang, C-S., D. A. Kunz, and B. J. Venables. 1996. Incorporation of molecular oxygen and water during enzymatic oxidation of cyanide by Pseudomonas fluorescens NCIMB 11764. Appl. Environ. Microbiol. 62:2195-2197.62.