Effect of combined treatments between gamma irradiation, spices and/or thermal treatment on the viability and enterotoxicity of Staphylococcus aureus

Heat-irradiation combination sequence decreased the thermal resistance of S. Aureus. The synergistic effect increased by increasing either the pre-irradiation thermal exposure time or by increasing the radiation dose. The complete inhibition of bacterial cell was recorded by pre-irradiation thermal treatment at 65, 60 and 55C for 5, 15 and 25 minutes, respectively, at the irradiation dose 0.5 kGy. Combination treatment between irradiation and species decreased the lethal species concentration from 2% to 1% at irradiation dose 0.25 kGy for all examined species and to 0.5% concentration with the irradiation dose 0.5 kGy. The combination treatments between species, temperature and radiation had a great synergistic effect on S. Aureus cells comparable with the individual treatment or with the combination treatment between two factors. There was no variation in the amounts of enterotoxin produced by the organism after treated by the sublethal doses of the combined three factors except in case of mint, which recorded 200% increase for untreated cells

Effect of cephalosporin, kanamycin and irradiation on total lipids, phospholipids, neutral lipids and sterols contents of bacillus megaterium and E. coli

Cephalosporin treatment decreased total, phospho and neutral lipids of B. Megaterium and E. Coli in both solid and liquid media, expect neutral lipids of E. coli treated with cephalosporin. Total neutral and sterols contents of B. megaterium treated with kanamycin decreased by using solid media and increased in liquid media, while phospholipids increased when both media are used. On the other hand, all lipid fractions of E. coli treated with kanamycin increased, when both solid and liquid media were used. Qualitative and quantitative variations were noticed in the fatty acids pool of the non-treated and treated B. Megaterium and E. coli. In the treated inocula, one or more fatty acids disappeared from the treated cells. Percentage of the saturated fatty acids of control and treated B. Megaterium were less than E. Coli. A significant increase in total, neutral lipids and sterols contents were recorded in cells of B. Megaterium arising from irradiated inocula, while there was a significant decrease in the phospholipids contents of irradiated inocula. On the other hand, E. coli behaved in opposite direction of B. Megaterium. Radiation increased the percentage of saturated fatty acids of both organisms than control

Cholesterol degradation by some microorganisms isolated from different Egyptian cultivated soils

Twenty fungal isolates belonging to four genera and eleven species and eleven bacterial isolates were isolated from different cultivated soils. These isolates were capable of utilizing cholesterol as a sole source of carbon. The bacterial isolates more active in cholesterol decomposition than fungal isolates. The highest cholesterol degradative activity and bacterial biomass was recoreded by Mycobacterium fortuitum being on [g/l] cholesterol 1.5, CaCO3 2.5, and yeast extract 5.0. The favorable incubation period was three days at 30C and pH 7.0

Effect of individual or combined freezing and gamma radiation treatment on the inactivation and injury of Micrococcus varians cells

Exposure of M. varians cells to subzero temperature [-2° and -20°]. Caused cell inactivation which increased gradually by increasing the storing period at subzero temperature. Sterile broth and radio-sterile fish were used as a suspending freezing menestrum, the latter was protective against the damaging effect of subzero temperature. Irradiation followed by freezing and storing at subzero temperatures induced a synergistic effect in the inactivation of M. varians cells. While, preliminary freezing and storing at subzero temperatures followed by irradiation revealed no synergism in cell deactivation. Irradiation M. varians cells were more sensitive to subsequent fast freezing than

Influence of feeding Lactobacillus acidophilus cells on serum cholesterol levels of rabbits

lactobacillus acidophilus strain was able to take up and assimilate cholesterol in the laboratory medium. This ability was increased by increasing cholesterol concentration and it was also a function of the bacterial growth. The data indicated that feeding the rabbits a diet high in cholesterol caused an increase in serum cholesterol level. Ingestion of L. acidophilus cells resulted in reduction of serum cholesterol, if mixed with either basal diet or fermented milk. It was also noticed that lactobacillus spp. had an antagonistic effect against E.coli of bowel natural flora