Effect of button mushroom compost on mobilization of heavy metals by sunflower

Abstract

The potential ability of Button mushroom compost (BMC) to solubilize heavy metals was estimated with metalcontaminated soils collected from abandoned mines of Boryeong area in South Korea. The bacterial strains in BMC were isolatedfor investigating the mobilization of metals in soil or plant by the strains and identified according to 16S rRNA gene sequenceanalysis. When metal solubilization potential of BMC was assessed in a batch experiment, the BMC was found to be capable ofsolubilizing metals in the presence of metals (Co, Pb and Zn) and the results showed that inoculation of BMC could increase theconcentrations of water soluble Co, Pb and Cd by 35, 25 and 45% respectively, than those of non-inoculated soils. BMC-assistedgrowth promotion and metal uptake in sunflower (Helianthus annuus) was also evaluated in a pot experiment. In comparisonwith non-inoculated seedlings, the inoculation led to increase the growth of H. annuus by 27, 25 and 28% respectively in Co, Pband Zn contaminated soils. Moreover, enhanced accumulation of Co, Pb and Zn in the shoot and root systems was observed ininoculated plants, where metal translocation from root to the above-ground tissues was also found to be enhanced by the BMC. The apparent results suggested that the BMC could effectively be employed in enhancing phytoextraction of Co, Pb and Zn fromcontaminated soils.