Effects of DNP on the cell surface properties of marine bacteria and its implication for adhesion to surfaces

Abstract

The effect of 2, 4-dinitrophenol (DNP) on the extracelluar polysaccharides (EPS), cell surface charge, and the hydrophobicity of six marine bacterial cultures was studied, and its influence on attachment of these bacteria to glass and polystyrene was evaluated. DNP treatment did not influence cell surface charge and EPS production, but had a significant effect on hydrophobicity of both hydrophilic (p = 0.05) and hydrophobic (p = 0.01) cultures. Significant reduction in the attachment of all the six cultures to glass (p = 0.02) and polystyrene (p = 0.03) was observed after DNP treatment. Moreover, hydrophobicity but not the cell surface charge or EPS production influenced bacterial cell attachment to glass and polystyrene. From this study, it was evident that DNP treatment influenced bacterial cell surface hydrophobicity, which in turn, reduced bacterial adhesion to surfaces.

Keywords:

• Biofilm
• 2
• 4-dinitrophenol
• hydrophobicity
• surface charge
• EPS
• cell attachment
• glass and polystyrene coupons

Acknowledgements

The authors thank Dr Satish R Shetye, the Director NIO, for his support and encouragement. The first author thanks CSIR (India) for granting a research fellowship to him. This manuscript is NIO contribution number 4239.