In recent years, phytoremediation (the utilization of plants, animals and microorganism to take up or immobilize hazardous substances from contaminated soils) has been widely applied to the remediation of Cadmium (Cd) contaminated soil. It's essential to screen natural microbes that being capable to concentrate hazardous substances during the development of phytoremediation technology. 

Researchers from the Wuhan Botanical Garden of the Chinese Academy of Sciences (CAS) investigated the abundance and composition of microbial community in heavy metal polluted soil. They isolated a Cd resistant microorganism, 'Penicillium janthinellum ZZ-2', from heavy metal contaminated soils, which was proven to enhance the growth and Cd uptake of bermudagrass.  

Long-term exposure to heavy metal contamination reduced both microbial biomass and activity, but did not result in large shifts in community composition. ZZ-2 inoculated bermudagrass plants showed higher plant growth, reduced Cd-toxicity symptoms and increased accumulation of Cd in the shoots and roots under Cd stress.

ZZ-2 contributed to the protection of plants from the inhibitory effects of high concentrations of Cd, and promoted the plant growth and Cd uptake by production of indole acetic acid or by solubilization of Cd in soils.  

This study suggests that Penicillium penicillium ZZ-2 could be a potential supplement to enhance the phytoremediation efficiency of plants in heavy metals contaminated soils.    

This work entitled "Identification of Cd-resistant microorganisms from heavy metal-contaminated soil and its potential in promoting the growth and Cd accumulation of bermudagrass" has been recently published in Environmental Research. 

This research was financially supported by the National Natural Science Foundation of China and the Youth Innovation Promotion Association of CAS.  

Proposed model for the Penicillium janthinellum ZZ-2-mediated protective plant responses to Cd stress. (Image by XIE Yan)