Bacterial Carbon Storage to Value Added Products

Microorganisms have evolved different systems for storing carbon during times of stress. In the cell’s natural environment, the stored carbon can then be utilized for growth when other nutrients are in better supply. Storage of carbon and other nutrients is ubiquitous throughout the prokaryotic and eukaryotic domains of life. These carbon storage molecules have great industrial importance. They can be useful as value-added products, as either biopolymers or biofuels, and cells are grown in large quantities and these compounds are harvested, usually as a replacement for a petroleum-based product. Nowadays, entire industries have been generated based on the production and utilization of these compounds. We focus on two bacteria that could be considered paradigms of their particular carbon storage strategy: Ralstonia eutropha and Rhodococcus opacus . R. eutropha has been well-studied as a polyhydroxyalkanoate (bioplastic) producer and R. opacus is a model bacterium for high yield triacylglycerol (TAG) production for biofuels. Both species produce carbon storage molecules that can potentially diminish our reliance on fossil-based petroleum. However, in both cases, there are challenges that must be overcome before profitable production schemes are established using these organisms. We explore the previous and current works to address these challenges in this review.