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. 

The Molecular Breeding of Turfgrass and Forage Grass Group of Wuhan Botanical Garden investigated the abundance and composition of microbial community in heavy metal polluted soil. A Cd resistant microorganism, ‘Penicillium janthinellum ZZ-2’, was isolated and was proven to enhance the growth and Cd uptake of bermudagrass.   

Results showed that long-term exposure to heavy metal contamination reduced both microbial biomass and activity, but did not result in large shifts in community composition. A Cd-resistant fungus 'Penicillium janthinellum ZZ-2’ was isolated from heavy metal contaminated soils. 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. The 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 (IAA) 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. 

Dr. XIE Yan from Wuhan Botanical Garden and the graduated student BU Heshen are the first co-authors, and Professor CHEN Liang is the corresponding author. This research was financially supported by the National Natural Science Foundation of China and by the Youth Innovation Promotion Association of Chinese Academy of Science.  

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