Ph ton 386 International Journal of Biotechnology. Photon 112 (2014) 386-391 https://sites.google.com/site/photonfoundationorganization/home/international-journal-of-biotechnology Original Research Article. ISJN: 3352-7304: Impact Index: 4.23 International Journal of Biotechnology Ph ton FT-IR analysis of bacterial biomass in response to heavy metal stress Annika Durve * , Naresh Chandra Department of Biotechnology, Birla College of Arts, Science and Commerce, Kalyan, Dist Thane. MS., India Article history: Received: 17 March, 2014 Accepted: 27 March, 2014 Available online: 22 April, 2014 Keywords: Bacterial cells; Heavy metals; Spectroscopic analysis; Fourier transform infrared spectroscopy (FTIR) Corresponding Author: Durve A.* Ph.D Student Email: annikadurve@yahoo.com Phone: +919619070330 Abstract The selected bacterial isolate Pseudomonas aeruginosa, showing tolerance to heavy metal salts viz. mercury, cadmium, arsenic and lead, was isolated from effluent samples. In this work, a combination of vibrational Fourier transform infrared (FTIR) spectroscopic techniques were applied to determine the overall structural and compositional changes in bacterial cells after heavy metal stress. FTIR analysis showed the changes of several peak positions in the spectrum pattern when Pseudomonas aeruginosa was grown in medium containing heavy metals viz. Hg, As, Pb and Cd indicating that there are functional groups viz. carboxyl, hydroxyl, phosphate, amino and amide, present on the bacterial cell surface. These functional groups may facilitate heavy metal binding on the cell surface of the bacterial cells. Citation: Durve A., Chandra N., 2014. FT-IR analysis of bacterial biomass in response to heavy metal stress. International Journal of Biotechnology. Photon 112, 386-391. All Rights Reserved with Photon. Photon Ignitor: ISJN33527304D672922042014 1. Introduction Heavy metals are increasingly found in microbial habitats due to natural and environmental processes and microbes have evolved several mechanisms to tolerate the presence of heavy metals. These mechanisms include the efflux of metal ions outside the cell, accumulation and complexation of metal ions inside the cell and reduction of the heavy metal ions to a less toxic state. Microbiological processes are of significance in determining metal mobility and have a potential application in bioremediation of metal pollution. The intake and subsequent efflux of heavy metal ions by microbes usually includes a redox reaction involving the metal. Bacteria that are resistant to and grow on metals therefore play an important role in the biogeochemical cycling of those metal ions. This is an important implication of microbial heavy metal tolerance because the oxidation state of a heavy metal relates to the solubility and toxicity of the metal itself (Malekzadeh et al., 2002). FTIR spectroscopy is a valuable technique due to its high sensitivity in detecting changes in the functional groups belonging to the components of bacteria, such as lipids and proteins. This shift in the peak positions, bandwidth and the intensity of the bands all give valuable structural and functional information. This technique requires neither reagent nor sample preparation and is non-destructive and highly selective because of its ability to be a spectral fingerprint for molecular components. FT-IR spectroscopy has proved to be a powerful tool to comply with the purpose of comprehensive characterisation. The unique characteristic of the material presented by the spectrum shows material properties, its behaviour as well as on specific components represented by their functional groups. The substantial progress regarding the infrared spectroscopic measurement is achieved by the recording of the interferogram. This combination provides many advantages and has caused a high interest in this method for process and quality control in many areas (Mantsch and Chapman, 1996; Moron and Cozzolino, 2004; Pollanen et al., 2005; Zhang et al., 2005).