Pseudomonas aeruginosa improved the phytoremediation efficiency of ryegrass on nonylphenol-cadmium co-contaminated soil

The effect of Pseudomonas aeruginosa ( P. aeruginosa ) on the phytoremediation efficiency of ryegrass on soil contaminated with nonylphenol (NP) and cadmium (Cd) was investigated by pot experiments. Pseudomonas aeruginosa application stimulated the adsorption of Cd by ryegrass and facilitated the biodegradation of NP in the soil. Exogenous P. aeruginosa inoculation increased the activities of urease, dehydrogenase, and polyphenol oxidase in the soil of the T4 treatment by 38.5%, 50.0%, and 56.5% compared to that of the T2 treatment, respectively. There was a significant positive correlation between the activities of dehydrogenase and polyphenol oxidase and the NP removal rate ( P  < 0.001). The relative abundances of beneficial microorganisms (such as Sphingomonas , Lysobacter , Streptomyces , Chloroflexia, Deltaproteobacteria, and Alphaproteobacteria) were increased as a result of P. aeruginosa inoculation. These microorganisms play important roles in nutrient cycling, Cd adsorption, and NP degradation. Additionally, P. aeruginosa was not the dominate bacterial species at the end of the experiment. According to this study, P. aeruginosa application improved the phytoremediation efficiency of ryegrass on soil contaminated with NP and Cd, with a minimal risk of alien microbial invasion.