The effect of Herbaspirillum seropedicae inoculation and/or maize straw (0, 5 and 10 Mg/hm2) amendment on the growth and N2 fixation of wheat was determined in pot experiments using 15N-dilution method. Inoculation resulted in accumulation of fixed nitrogen, and % N from atmosphere being 24.6 and 26.5% in wheat shoot and grain, respectively. Straw amendment reduced % Natm to 16.1 and 20.2% at high straw level (10 Mg/hm2). Rational nitrogen fertilization (180 kg N/hm2) completely inhibited N2 fixation by H. seropedicae inoculation. Bacterial inoculation increased dry shoot and grain yield up to 23 and 31%, respectively. The highest levels of shoot and grain dry mass (46.5 and 42.4%) were obtained by N-fertilization in both inoculated and uninoculated plants. Total shoot and grain N-yield increased irrespective of organic matter amendment by inoculation up to 9 and 25%, respectively. N-fertilized plants recorded a maximum increase in N-yield (57 and 51%). H. seropedicae was reisolated from inoculated wheat histosphere after harvesting (90 d from sowing). Neither organic matter nor mineral nitrogen applications had any marked effect on bacterial total counts colonizing wheat histosphere. Moreover, no symptoms of mottled stripe disease were observed on leaves and stems of inoculated plants.

Pyrogens are fever-producing substances, which are metabolic products of microorganisms. Endotoxins are the most potent pyrogens. Depyrogenation can be defined as the elimination of all pyrogenic substances which is an important part of the manufacture of sterile pyrogen free pharmaceutical products. This study compared between sterilization and depyrogenation using moist heat by autoclave, as well as dry heat. After incubation period (24 hours) at 55 o C-60 o C the color of Geobacillus stearothermophillus spores' control vial which didn't sterilized in autoclave changed from blue to yellow color representing the (+ve) result, while the other sterilized vials have no color change (-ve). In addition, all examined endotoxin containing ampoules showed gel formation (+ve) when examined by Limulus Amebocyte Lysate )LAL). All ampoule groups that have autoclaved for periods of 1 hour to 4 hours showed gel formation (+ve) after LAL test, while only the last group which have autoclaving periods of 5 hours (5 cycles) showed no gel formation (-ve). Sterility of vials that contained spores of Geobacillus stearothermophillus after dry heating at 250 o C for 30 min showed no color change (-ve). In addition, LAL test for endotoxin containing ampoules after dry heating at 250 o C for 30 min showed no gel formation representing (-ve) pyrogen. So, moist heat is effective in sterilization and not for depydrogenation, whereas, dry heat is effective in sterilization as well as for depyrogenation.