Inoculation of bacteria for the bioremediation of heavy metals contaminated soil by Agrocybe aegerita

Abstract

The combination of mushrooms and bacteria was used as a novel technique to remediate soils polluted by heavy metals. Pot experiments were conducted to investigate combined effects of Agrocybe aegerita and Serratia spp. on Ni and Cd polluted soils. The impacts of single inoculation and co-inoculation of Serratia spp. on the growth of A. aegerita, bacterial counts, accumulation of Ni and Cd by A. aegerita, heavy metal speciation and enzymatic activities in soil, along with bacterial community structure were studied. The results indicated that mushroom biomass was promoted by both solitary inoculation and co-inoculation. The increase of bacterial numbers and soil enzymatic activities, and the greater amount of heavy metals in A. aegerita also showed that these combinations could alleviate the heavy metals stress more energetically. Simultaneously, proportions of HOAc extractable and residual metals in soil with A. aegerita and bacteria were respectively higher and lower than those in other treatments, supporting the idea that combinations could activate heavy metals better. Furthermore, the high throughput Illumina pyrosequencing analysis revealed the impacts of different treatments on the bacterial community structure and composition, reinforcing that the integration of bacteria and mushroom was an effective method for bioremediation of soil with heavy metals.