Carbon isotope fractionation studies of bacterial strain Rhodococcus rhodochrous MTCC 291.

ABSTRACT

Carbon isotope fractionation associated with the aerobic consumption of propane (C3) were determined using Rhodococcus rhodochrous MTCC 291 bacterial strain to estimate the amount of hydrocarbon oxidized using GC, fractionation of δ13C carbon isotopes of propane and CO2 using GC-C-IRMS and growth of bacteria by UV-Visible Spectrophotometer. The initial δ13C isotopic value of propane was -34 ‰ and after incubation the changes of the isotopic values have been determined on 6th, 10th, 14th, and 17th days. The propane isotopic fractionation value was found to be maximum of -38.0 ‰ with an average value of -36.5 ‰ and a standard deviation of -1.22 ‰. The initial δ13C isotopic value of CO2 was -19.601 ‰. The CO2 isotopic fractionation value was found to be maximum of -29.153 ‰ with an average value of -26.859 ‰ and a standard deviation of -28.338 ‰. The consumption of propane gas was estimated using Gas Chromatograph. The initial concentration of propane in control was found to be 53 ppm. On incubation, the consumption of the propane gas was observed to be of 26 ppm. The carbon isotope fractionation presented here may be applied to estimate the extent of C1-C4 oxidation in natural gas samples, and should prove useful in further studying the microbial oxidation of these compounds in the natural environment.