Developed fungal–bacterial biofilms as a novel tool for bioremoval of hexavelant chromium from wastewater

Abstract

Remediation measures for hexavalent chromium [Cr(VI)] are required for a safe environment. As a recent development in microbiology, bacterial biofilms are being studied as effective bioremediation agents. When bacteria are in fungal surface-attached biofilm mode, they are called fungal–bacterial biofilms (FBBs). They have not been tested for bioremediation so far. Hence, this study was conducted to develop FBBs and glass-wool-attached bacterial biofilms (BBs), and to evaluate Cr(VI) tolerability and removal of bacterial monocultures, BBs and FBBs. FBBs showed a significantly high level of Cr(VI) tolerance and resistance compared with its BBs or monocultures. After 10 days, up to 90% of Cr(VI) had been removed, which was significantly higher than that of BBs or its monocultures. Thus, it is clear that FBBs can be used as a novel tool to decontaminate Cr(VI) both in situ and ex situ.

Keywords:

• Cr(VI)
• bioremediation
• fungal–bacterial biofilms
• tolerance
• resistance

Acknowledgements

Prof. T. Pradeep and Dr Sajan Lal at IIT, Madras, for their support on SEM. Ms Sara Gunaratne, Ms K. Karunaratne and Mr M. A. Lal of the unit helped in the laboratory preparations and analyses.