Compost Biostimulation for Improved Soil Bioremediation using Endophytic Bacillus Sp.

The use of bacterial endophytes in soil bioremediation is limited by nutrient availability in the soil. In this study, garden compost was used as a biostimulant during the bioremediation of lead contaminated soil with a bacterial endophyte. The experimental data showed that the cell wall of the Bacillus sp. strain MHSD_36 resulted in 36% lead biosorption. The addition of glucose and peptone in the growth media, enhanced biomass growth and lead biosorption, achieving a maximum of 76% lead removal. The use of compost as a cheaper carbon and nitrogen source improved the biosorption capacity of strain MHSD_36 during the bioremediation of lead contaminated soil. Compost biostimulation resulted in a residual lead of 250 mg/Kg, from an initial concentration of 300 mg/Kg, compared to 282 mg/Kg without biostimulation. The endophytic bacteria Bacillus sp. strain MHSD_36 is a potential lead biosorbent. Moreover, compost is an organic biostimulator with potential application in soil decontamination.