Characterization of structural properties of fungal-bacterial biofilms by Fourier Transform Infrared Spectroscopy

Abstract

Investigating the structural properties of biofilms is important as they undergo profound changes in their genetic and cellular make up once planktonic cells are converted to biofilm communities. Present study focused on examining the structural attributes of fungal-bacterial biofilms (FBBs), a novel introduction to biotechnological applications, in comparison to bacterial (BBs) and fungal (FBs) biofilms. Enterobacter sp. and Aspergillus sp. were used as the bacterial and fungal counterparts in biofilms. FBB, BB and FB were developed in vitro in a prescribed Biofilm Formation Medium. The biofilm formation was observed under the light microscope. The biofilms were pelletized and Infra-Red spectra were recorded using Fourier Transform Infrared (FTIR) spectroscopy. FTIR analysis clearly showed the presence of Amide I (~1635 cm-1) and II (~1544 cm-1), C-O and P=O stretching, and CH2 scissoring in FBB and BB. FB showed only the Amide I band. The absorbance values of above functional groups, cellular polysaccharides, amides and fatty acids gradually increased in the first three days of biofilm maturation and then leveled off. FBB showed higher accumulation of all macro molecules recorded at each sampling time, thus demonstrating its increased metabolic activity compared to BB and FB.

Keywords

• biofilms, fungal-bacterial biofilms, structural properties, ftir