Defining the Putative Symbiosis Between an Algae and Potential Pathogenic Bacteria

The microalga Botryococcus braunii is of particular interest to biofuel development because of its natural production of C30 isoprenes that may be utilized as biofuel. In efforts to characterize the algae’s growth, a novel bacterium was isolated belonging to the Bradyrhizobium genus according to 16s rRNA sequencing. Initial interest in this bacterium was fueled by the possibility of nitrogen fixation capabilities, thus laying the grounds for a symbiotic relationship. However, upon whole genome sequencing, the bacteria was found to be a novel strain closely related to the human pathogen Pseudomonas aeruginosa. Further analysis of the genome reveals the bacterium to have qualities suggestive of a symbiotic relationship despite the missing nitrogen fixation operon. Ultimately, this relationship will be exploited to increase growth rate for the high-value but slow-growing microalga.