Abstract

Biosurfactant-producing bacterial isolate can bioremediate heavy metals. The major objective was to understand the role of Bacillus paramycoides NT001 and its biosurfactant to bioremediate copper (Cu). In silico, studies were also performed to explore the role of the different genes responsible for the Cu remediation. The ability of biosurfactant production was confirmed by analyzing surface tension and the emulsification index. Fourier transmission infrared spectroscopy and liquid chromatography-tandem mass spectrometry analysis identified the extracted biomaterial as surfactin type of biosurfactant. The in silico analysis revealed the close evolutionary relatedness of the thioesterase domain protein, an integral component in the non-ribosomal peptide synthetase cluster amongst Bacillus species. Furthermore, a similar closeness amongst Bacillus species was present when Cu-exporting P-Type ATPase protein, responsible for Cu bioremediation, was phylogenetically analyzed. The atomic absorption spectroscopic and energy dispersive X-ray spectroscopic studies confirmed that the surfactin biosurfactant could reduce the Cu from the contaminated soil. Following treatment, the percentage of Cu reduction was roughly 51.72%. This synergistic activity of the bacteria and the surfactin biosurfactant can be a future module for bioremediation of Cu -contaminated soil.

Key words: Bioremediation, biosurfactant, Bacillus paramycoides, copper, textile, Clean soil