Biosorption of Lead (Pb) by Three Bacillus species (Bacillus cereus, Bacillus pumilus and Bacillus subtilis) Isolated from Scirpus grossus

Abstract

Heavy metal is to be a common problem on aquatic pollution, and heavy metal oflead (Pb) is one of the most spread found in the environment. Several technologieshave been used to solve this problem but most of them are expensive.Phytoremediation technology recently becomes a solution to apply due to itsadvantages of green technology and low cost. In this technology, beside plantspecies, the bacteria that grow in root zone of plants have an important role. Thisstudy conducted a lead biosorption test using Bacillus subtilis, one of rhizospherebacteria isolated from Scirpus grossus to determine its ability to adsorb Pb from themedium and to be used to enhance the performance of phytoremediation process.The observation was done within 48 hours on bacteria growth on Trypticase SoyBroth (TSB) medium containing Pb with concentrations of 0, 200 and 600 mg/L. Themonitoring growth parameters consist of Colony Forming Unit (CFU) and OpticalDensity (OD) including Pb concentrations inn TSB medium and bacteria cell. Theresults show that the reduction percentage of bacteria growth in medium containing200 mg/L Pb were 36.5% log CFU and 33.3% OD, where as for medium containing600 mg/L Pb, the reduction was even higher (52.4% log CFU and 50.0% OD), givingevidence that this species has tolerance to growth in Pb contained medium and hasability to adsorp Pb into its cell.