Effect of gamma radiation exposure given to wild type lactic acid bacteria LPA6 on MRS agar: A, un-irradiated; B, irradiated with 75 Gy; C, Survival percent of LPA6 vs gamma radiation (0-100 Gy) exposure (semi-log). Bacterial cells were exposed to four doses (25, 50, 75, 100 Gy) of gamma rays. Values are survival (%) mean with ±SD.