A FOURIER TRANSFORM INFRARED (FTIR) SPECTROSCOPIC STUDY ON CELLULAR CHANGES IN THE MARINOCOCCUS LUTEUS SSLB 1 UNDER DIFFERENT SALINITY REGIME

Abstract

Marinococcus luteus SSLB1, isolated from the Sambhar Salt Lake, Rajasthan, India, could tolerate NaCl upto 25%, (w/v) concentration in a complex medium. The overall structural and compositional changes in the bacterial isolate in the presence of variable concentrations of NaCl (0-25%) was analyzed by Fourier transform infrared (FTIR) spectroscopic techniques. Results on FTIR analysis showed NaCl induced changes in the absorption peaks corresponding to different functional groups in the M. luteus SSLB1. The wavenumber 1537.6 cm^-1 (Amide- II), 1538.9 and 1544.5 cm^-1 N-H (symmetric) bending exhibited band shift at lower NaCl concentration, but they disappeared at the higher concentrations. Similarly FTIR bands observed between 1300-1500 cm^-1 wave numbers, arising predominately from >CH₃ symmetric deformation, COO^2- stretching (symmetric) of fatty acids and wavenumber 1400.9 cm^-1 shifted to higher frequency of wave numbers. These results indicated NaCl induced adaptational and structural changes in M. luteus. as evident from increase or decrease or shift in the characteristic FTIR peaks assigned to different functional groups.