Oil mineral aggregates engineered from bio-synthesized calcite nanoparticles for improved crude oil biodegradation

Biodegradation has been the most sought method for degradation of various xenobiotic contamination including crude oil contamination, but it has shown limited efficiency due to the hydrophobic property of the crude oil. In order to overcome this drawback, microbial species along with minerals having ability to adsorb oil onto its surface can be used to increase its availability. In this study, an attempt to increase the bioavailability of the crude oil by adsorption by addition of the oil degrading microorganisms to the ex-situ system was performed to determine efficiency. Firstly, the study involved the synthesis and characterization of the nanoparticles obtained from calcium carbonate shells of Semibalanus balanoides (Acorn Barnacles), and the isolation of Paenibacillus dentritiformis (a Gram-positive bacterium) for production of oil mineral aggregate (OMA). The synthesized calcite nanoparticles were characterized using XRD, FTIR, ZETA Sizer and Potential, HR- SEM, EDS, HR-TEM. The structural analysis showed that the OMA was larger in size compared to cuboidal nanoparticles at 500 nm. Further, the degradation potential of the OMA was comparatively more at 88% and the biodegradation potential of P. dentritiformis was 67% when compared to the control. These results suggested that the change in the surface morphology of the nanoparticles by the formation of OMA reduced the hydrophobicity of the crude oil, thereby increasing its bioavailability for enhanced degradation.