Nabil A. Hegazi

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Gluconacetobacter- like diazotrophs were encountered as dense populations inside the root and stem tissues of sugarcane cultivated in ancient agricultural fields of the Nile Delta. Counts of >105 cells g-1 were recorded in root and stem samples. The leaves contained a smaller population (<103 g-1). The typical dark-orange colonies which developed on LGIP(More)
  • N A Hegazi
  • 1979
The present survey includes 156 representative soil samples. Results obtained confirm the richness of Egyptian soils, particularly the Nile Valley soils, in Azotobacter (60% of the samples contained greater than 10(3) colonies/g soil). Colony counts were lower than MPN estimations. Glucose is recommended for use in plating medium. Among the environmental(More)
Among 42 plant species representing the flora of north Sinai, two possessed sand grain sheath encasing the roots. They are Panicum turgidum Forssk. and Stipagrostis scoparia (Trin.and Rupr.) deWinter. Rhizosheaths, compared to surrounding free sand, accommodated higher population density of microorganisms including associative diazotrophs. Isolates secured(More)
Inoculated and non-inoculated seedlings of maize were grown in fertile clayloam soils of Egypt and Belgium under subtropical conditions provided in a greenhouse. Acetylene-reducing activity and microbial counts were determined during a period ranging from 6 to 12 weeks after sowing. Irrespective of soil origin, N(2)-fixing spirilla and Azotobacter were(More)
The pattern of N2-ase activity in clay-loam soil of Nile Delta was determined. However, unamended soil showed somewhat low activity: an amount of 18–95 mg N2 fixed/kg soil/year was calculated. Addition of glucose greatly enhanced such activity and efficiencies of N2-fixation increased with decreasing carbon source concentration. Highest activities (800 n(More)
Organic agriculture as well as good agricultural practices (GAPs) intrigues the concern of both consumers and producers of agricultural commodities. Bio-preparates of various rhizospheric microorganisms (RMOs) are potential sources of biological inputs supporting plant nutrition and health. The response of open-field potatoes to the application of RMO(More)
Our previous publications and the data presented here provide evidences on the ability of plant-based culture media to optimize the cultivability of rhizobacteria and to support their recovery from plant-soil environments. Compared to the tested chemically-synthetic culture media (e.g. nutrient agar and N-deficient combined-carbon sources media), slurry(More)
Acetylene-reducing activity and populations of diazotrophs were estimated simultaneously in Giza soils after harvest of wheat and maize crops. Amendment of soil with residues of either crop together with flood irrigation enhanced the development of diazotrophs and nitrogenase activities in the soil. Bacterial numbers and acetylene-reducing activity(More)
We have developed teabags packed with dehydrated plant powders, without any supplements, for preparation of plant infusions necessary to develop media for culturing rhizobacteria. These bacteria are efficiently cultivated on such plant teabag culture media, with better progressive in situ recoverability compared to standard chemically synthetic culture(More)
North Sinai deserts were surveyed for the predominant plant cover and for the culturable bacteria nesting their roots and shoots. Among 43 plant species reported, 13 are perennial (e.g. Fagonia spp., Pancratium spp.) and 30 annuals (e.g. Bromus spp., Erodium spp.). Eleven species possessed rhizo-sheath, e.g. Cyperus capitatus, Panicum turgidum and(More)