Fourier transform infrared spectroscopy (FTIR) 
Bacillus mycoides NR5 was grown on 25 mg L-1amended medium and without As was taken as control. Cells were harvested by centrifugation and 2.0 mg dried biomass was mixed and ground with 98.0 mg of potassium bromide (KBr) in an agate mortar. Translucent discs were prepared by pressing the KBr grounded pellets with the aid of 14 tons of pressure beneath the bench press. The KBr pellets were immediately analysed with a spectrophotometer in the range of 400-4000 cm-1 with a resolution of 5 cm-1.