Re-estimation of gamma irradiation sterilizing dose of locally produced gloves

This work aimed to re-estimate the value of sterilizing dose of the locally produced gloves. Also, the scope of this work was limited by isolation, purification and identification of bacterial flora of gloves locally manufactured in Egypt. The bacterial flora of the locally produced gloves were found to be sporeforming bacteria, mainly Bacillus firmus, B. alvei, B. subtilis, B. circulans and B. pantothenticus. These isolates were resistant to radiation and thermal treatment. The D10- value for the isolated strains was estimated in the range of 2.7 to 3.2 kGy. The most radioresistant isolate was B. circulans with D10 value 3.2 kGy when the cells were irradiated in a form of dry test pieces [108 colony forming units]. When B. circulans 108 colony forming units] were used to deliberately contaminate the gloves materials, D10- value was 1.8 kGy. In order to confirm these results standard strain B. pumilus E601 was used instead of B. circulans. The D10-value of B. pumilus was determined to be 3.2 and 2.5 kGy under the previously mentioned conditions respectively. The results indicated that the sensitivity of the isolated and the reference strains increased when the gloves materials were used as a substrate during the process of irradiation. Accordingly, it was proved that the material of the substrate affects the value of the sterilizing dose

Effect of gamma radiation on mycotoxin production by toxigenic moulds in local karish cheese

Forty-two random samples of Karish cheese were collected and analyzed for mycotoxins and the effect of gamma irradiation on growth and production of mycotoxins by toxigenic stains of Penicillium in Karish cheese was studied. Of the 42 samples only 2 [4.7%] were positive for ochratoxin A and all samples were negative for aflatoxin, penicillic acid, citrinin and cyclopiazonic acid. In addition of 108 cultures of Penicillium spp. And Aspergillus spp. Only 23 were positive for cyclopiazonic acid, 13 for aflatoxin B1, 9 for ochratoxin A, 8 for penicillic acid, and 4 for citrinin. Cheese samples were inoculated with conidia of P. viridicatum, P. cyclopium and P. chrysogenum and then irradiated at a dose of 1.5 and 3.5 kGy and incubated for prolonged period at 25C of colony-forming units was lower than the unirradiated controls. Ochratoxin A, cyclopiazonic acid and penicillic acid production by P. viridicatum, P. cyclopium and P. chrysogenum decreased from the control level with increased dose and were not detected at 4.0 kGy