Employing Automated Experimental Evolution to Understand Survival Strategies of Lab-Grown ExtremophilesExperimental evolution (EE) exposes microbes to intentional stressors to improve resistance through artificial mutation. The resulting changes to metabolic pathways, protein structure, and genetic sequences, along with traditional genetic engineering tools, to can help understand the mechanisms of improved tolerance. An automated experimental set-up -- the Automated Adaptive Directed Evolution Chamber (AADEC) -- with minimal scope for human interference was developed at NASA Ames. A second- generation device integrating more real-time biochemical sensors has been developed recently. Added sensors include pH for indicating metabolic products, oxidation-reduction potential (ORP) for indicating available/consumed metabolic energy, dissolved oxygen (DO) for indicating aerobic/anaerobic growth cycles, and electrical conductivity (EC) as an additional indicator of metabolic products. With four additional sensors, the system is biochemically more informative in real-time. More importantly, each sensor parameter can be used as a selection pressure, individually or in combination with others, to artificially create and control inhospitable environments analogous to extremophile habitats for microbial growth in the lab. Potential stressors to be added in the future include thermal, reactive oxygen species, metal-ion concentrations, and varying nutrient availability.
Document ID
20190029580
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Raj, Chinmayee Govinda (Georgia Institute of Technology Atlanta, GA, United States)
Bake, Aryamitra (San Jose State Univ. San Jose, CA, United States)
Taye, Ali-Imran (Georgia Institute of Technology Atlanta, GA, United States)
Ludman, Carrie (San Jose State Univ. San Jose, CA, United States)
Joshi, Purva (Sacred Heart Univ. Fairfield, CT, United States)
Wang, Jonathan (Millennium Engineering and Integration Co. Moffett Field, CA, United States)
Gentry, Diana (NASA Ames Research Center Moffett Field, CA, United States)