UC Davis

The biotechnological application of microorganisms for rhizoremediation of contaminated sites requires the development of plant-microbe symbionts capable of plant growth promotion and hydrocarbon degradation. Here, we present a study aimed at isolating single microbial strains that are capable of promoting plant growth as well as rhizoremediation of diesel fuel hydrocarbons. Through genomic analyses and greenhouse-based experiments, we examined the synergistic interactions of Medicago sativa L. and Paraburkholderia tropica WTPI1 for enhanced rhizoremediation of diesel fuel-contaminated soils. Plant growth-based experiments confirmed that the inoculation of M. sativa with P. tropica led to a 99% increase in plant biomass. Furthermore, organic geochemical analysis revealed that 96% of all the distinctive diesel fuel hydrocarbons, including C10–C25n-alkanes, branched alkanes, cycloalkanes and aromatic hydrocarbons were degraded in the M. sativa + P. tropica treatment. These results will prove beneficial for biotechnological application of P. tropica WTPI1 for plant growth promotion and most importantly for environmental remediation of organic pollutants.