Ryan Sullivan

Ryan Sullivan received his Ph.D. in Chemical Engineering from the University of Illinois at Urbana-Champaign under the supervision of Dr. Huimin Zhao. His research focused on improving biochemical production from plant hydrolysate sugars, particularly producing xylitol and biofuel from L-arabinose. Through his work, a highly active and stable L-arabinitol 4-dehydrogenase (LAD) from filamentous fungi Neurospora crassa was characterized and engineered for reverse cofactor specificity. This resulted in the first known NADP-dependent LAD, whose mutations could be placed in other fungal LAD enzymes with similar effect. The first crystal structure of LAD was also generated in collaboration with Dr. Satish Nair at the University of Illinois. The cofactor reversal was found to alleviate the redox balance and improve the flux from L-arabinose to downstream products. Dr. Sullivan also helped his lab to design and develop novel biochemical pathway assembly methods and screening assays for directed evolution.

Prior to his graduate work, Dr. Sullivan received his B.Ch.E. from the University of Minnesota. His undergraduate research, under Dr. Friedrich Srienc, was concentrated on investigating the limiting steps and precursor requirements for improved poly[(R)-3-hydrobutyrate] (PHB) accumulation in recombinant yeast, Saccharomyces cerevisiae. His work also led to optimized conditions for production of biodegradable polymers.

Dr. Sullivan's postdoctoral research at NREL will look into increasing Rubisco enzyme activity for more efficient CO₂ fixation for application in enhanced biodiesel production. Improvement of H₂ feedstock utilization in a recombinant host will also be a subject of interest.