Abstract
Ralstonia eutropha is capable of utilizing a plethora of simple and complex carbon-containing compounds. Growth has been demonstrated on carbon dioxide, glycerol, acetate, mixed organic acids, sugars, fatty acids, oils, and more. R. eutropha possesses oxygen-tolerant hydrogenases, which allow the bacterium to grow in aerobic lithoautotrophic conditions. When experiencing nutrient stress in the presence of excess carbon, R. eutropha can store carbon and energy in the form of polyhydroxyalkanoates (PHAs), a biodegradable and biocompatible plastic. Engineered R. eutropha strains are capable of producing PHAs with different chain lengths, resulting in different physical, biological, and chemical properties. These tailored PHAs, when depolymerized, can also serve as valuable chiral precursors for antibiotics, vitamins, perfumes, and pheromones. The native PHA carbon storage system can be genetically disabled and the carbon flux redirected to produce value-added chemicals such as biofuels and pharmaceuticals. Various strains of R. eutropha are also capable of bioremediation by breaking down phenol compounds and scavenging heavy metals in contaminated soils and water. Metabolic versatility and genetic tractability combined with its ability to convert a variety of carbon sources into storage molecules make R. eutropha an excellent platform organism for the production of value-added compounds.