Capability of Bacillus Subtilis to remove Pb 2+ via producing lipopeptides.

Lead contamination is widely found in soil and waters, which makes great threat to animal and human health. Environmentally friendly, efficient, and economical methods for the removal of Pb2+ pose significant challenges for environmental protection. Bacillus subtilis lipopeptide was firstly used to remove Pb2+ from water. In mechanisms, the lipopeptides formed complexes and chelated with Pb2+ via OH, CO, OCO, and NH. In kinetics, the Pb2+ removal process closely followed a pseudo-first-order model, and the equilibrium Pb2+ adsorption capacity ranged from 112.6 to 113.7 mg/g within a temperature range of 293.13–313.13 K. The Pb2+ removal process could be well described by a Langmuir isotherm. The maximum Pb2+ removal capability of lipopeptides was 164.4 mg/g in manually metal contaminated water and 130.4 mg/g in actual wastewater. Furthermore, the lipopeptides can not only decrease the amount of lead in oats grown, but also promote oat growth under Pb2+ stress. The results showed that lipopeptides can be used as a highly efficient adsorbent to remove Pb2+ from water, which means the great potential of lipopeptides in practical environments.