Mohamed Fayez - Academia.edu (original) (raw)

Papers by Mohamed Fayez

Research paper thumbnail of Rhizosheath of sinai desert plants is a potential repository for associative diazotrophs

Microbiological Research, 2004

Among 42 plant species representing the flora of north Sinai, two possessed sand grain sheath enc... 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 belonged to the species of Bacillus circulans, Paenib. macerans (Bacillus macerans), Enterobacter agglomerans, Agrobacterium radiobacter and Chryseomonas luteola (Pseudomonos luteola). The rhizosheath potentiality in revegetating sand dunes and arid lands, through nitrogen fixation, plant-water relationship and root continuity for nutrient uptake, are discussed.

Research paper thumbnail of Biodiversity of microorganisms in semi-arid soils of north sinai deserts

Archives of Agronomy and Soil Science, 2003

North Sinai environment is currently subjected to changes due to the major agricultural developme... more North Sinai environment is currently subjected to changes due to the major agricultural development project of El-Salam canal which brings Nile water to the arid deserts of Sinai. Therefore, intensive efforts are made to record biodiversity of natural microflora and ...

Research paper thumbnail of The crude plant juices of desert plants as appropriate culture media for the cultivation of rhizospheric microorganisms

Journal of Advanced Research

The exclusive use of plant juices, not as a mere supplement to synthetic culture media, for cultu... more The exclusive use of plant juices, not as a mere supplement to synthetic culture media, for culturing rhizospheric microorganisms (RMO) is introduced here. Juices were prepared from desert (Mesembryanthemum crystallinum L., Zygophyllum album L., Carpobrotus edulis L.) as well as cultivated (Trifolium alexandrinum L., Beta vulgaris L.) plants. Colonies of RMO (Azospirillum brasilense, Enterobacter agglomerans and Klebsiella pneumoniae) nicely developed on surfaceinoculated agar plates prepared from crude and diluted juice of M. crystallinum (ice plant). Furthermore, hundreds of RMO colonies developed on various standard culture media were replicated (>90%) on agar plates of different plant juices. RMO cells grew nicely in liquid ice plant juice, with doubling times comparable to those grown in the reference culture medium. RMO populations resident in various host plants were able to develop on culture media prepared from homologous and heterologous juices. The application of a thin semi-solid overlay agar on the surfaces of inoculated agar plates significantly increased the recovery of micro-colonies on agar plates, particularly those prepared from plant juices.

Research paper thumbnail of El-Salam canal is a potential project reusing the Nile Delta drainage water for Sinai desert agriculture: Microbial and chemical water quality

Journal of Advanced Research

... El-Salam canal is a potential project reusing the Nile Delta drainage water for Sinai desert ... more ... El-Salam canal is a potential project reusing the Nile Delta drainage water for Sinai desert agriculture: Microbial and chemical water quality. ... Keywords: El-Salam canal; North Sinai; Drainage water; Reuse of Nile water; Water pollution; Diazotrophs. ...

Research paper thumbnail of Intercropping of sesbania ( Sesbania sesban ) and leucaena ( Leucaena leucocephala ) with five annual grasses under semi-arid conditions as affected by inoculation with specific rhizobia and associative diazotrophs

Agronomie, 2001

Abstract – Intercropping of legumes and non-legumes is considered to improve the quality and quan... more Abstract – Intercropping of legumes and non-legumes is considered to improve the quality and quantity of field forage crops. Under semi-arid desert conditions, intercropping of leucaena and sesbania with some annual grasses (barley, pearl millet, and Rhodes-, rye-and sudan-...

Research paper thumbnail of Gluconacetobacter diazotrophicus : a natural endophytic diazotroph of Nile Delta sugarcane capable of establishing an endophytic association with wheat

Biology and Fertility of Soils, 2004

Gluconacetobacter- like diazotrophs were encountered as dense populations inside the root and ste... more 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 (3 g-1). The typical dark-orange colonies which developed on LGIP agar plates were purified. Identification was performed with the API microtube systems: API 20E for Enterobacteriaceae and API 20NE for non-Enterobacteriaceae. API profiles of the local isolates were closely related to those of the type culture Gluconacetobacter diazotrophicus (ATTC 49037). The isolates successfully reduced C2H2 and produced appreciable amounts of ethylene in the presence of cane juice. This suggested that the local isolates are closely related to the type strain G. diazotrophicus. Wheat seedlings were inoculated with a number of isolates under gnotobiotic conditions. Both optical and scanning electron microscopy showed that endophytic Gluconacetobacter spp. were present in all the samples tested. They were observed in apparently intact and enlarged epidermal root cells, and also in stem tissues, indicating that the bacterium was able to migrate upward into the shoot tissues. Although Gluconacetobacter inoculation did not stimulate the growth of the cereal plant, the results obtained are particularly interesting because this bacterial species was capable of colonizing the internal tissues of wheat, not considered a natural host until now.

Research paper thumbnail of Rhizosheath of sinai desert plants is a potential repository for associative diazotrophs

Microbiological Research, 2004

Among 42 plant species representing the flora of north Sinai, two possessed sand grain sheath enc... 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 belonged to the species of Bacillus circulans, Paenib. macerans (Bacillus macerans), Enterobacter agglomerans, Agrobacterium radiobacter and Chryseomonas luteola (Pseudomonos luteola). The rhizosheath potentiality in revegetating sand dunes and arid lands, through nitrogen fixation, plant-water relationship and root continuity for nutrient uptake, are discussed.

Research paper thumbnail of Biodiversity of microorganisms in semi-arid soils of north sinai deserts

Archives of Agronomy and Soil Science, 2003

North Sinai environment is currently subjected to changes due to the major agricultural developme... more North Sinai environment is currently subjected to changes due to the major agricultural development project of El-Salam canal which brings Nile water to the arid deserts of Sinai. Therefore, intensive efforts are made to record biodiversity of natural microflora and ...

Research paper thumbnail of The crude plant juices of desert plants as appropriate culture media for the cultivation of rhizospheric microorganisms

Journal of Advanced Research

The exclusive use of plant juices, not as a mere supplement to synthetic culture media, for cultu... more The exclusive use of plant juices, not as a mere supplement to synthetic culture media, for culturing rhizospheric microorganisms (RMO) is introduced here. Juices were prepared from desert (Mesembryanthemum crystallinum L., Zygophyllum album L., Carpobrotus edulis L.) as well as cultivated (Trifolium alexandrinum L., Beta vulgaris L.) plants. Colonies of RMO (Azospirillum brasilense, Enterobacter agglomerans and Klebsiella pneumoniae) nicely developed on surfaceinoculated agar plates prepared from crude and diluted juice of M. crystallinum (ice plant). Furthermore, hundreds of RMO colonies developed on various standard culture media were replicated (>90%) on agar plates of different plant juices. RMO cells grew nicely in liquid ice plant juice, with doubling times comparable to those grown in the reference culture medium. RMO populations resident in various host plants were able to develop on culture media prepared from homologous and heterologous juices. The application of a thin semi-solid overlay agar on the surfaces of inoculated agar plates significantly increased the recovery of micro-colonies on agar plates, particularly those prepared from plant juices.

Research paper thumbnail of El-Salam canal is a potential project reusing the Nile Delta drainage water for Sinai desert agriculture: Microbial and chemical water quality

Journal of Advanced Research

... El-Salam canal is a potential project reusing the Nile Delta drainage water for Sinai desert ... more ... El-Salam canal is a potential project reusing the Nile Delta drainage water for Sinai desert agriculture: Microbial and chemical water quality. ... Keywords: El-Salam canal; North Sinai; Drainage water; Reuse of Nile water; Water pollution; Diazotrophs. ...

Research paper thumbnail of Intercropping of sesbania ( Sesbania sesban ) and leucaena ( Leucaena leucocephala ) with five annual grasses under semi-arid conditions as affected by inoculation with specific rhizobia and associative diazotrophs

Agronomie, 2001

Abstract – Intercropping of legumes and non-legumes is considered to improve the quality and quan... more Abstract – Intercropping of legumes and non-legumes is considered to improve the quality and quantity of field forage crops. Under semi-arid desert conditions, intercropping of leucaena and sesbania with some annual grasses (barley, pearl millet, and Rhodes-, rye-and sudan-...

Research paper thumbnail of Gluconacetobacter diazotrophicus : a natural endophytic diazotroph of Nile Delta sugarcane capable of establishing an endophytic association with wheat

Biology and Fertility of Soils, 2004

Gluconacetobacter- like diazotrophs were encountered as dense populations inside the root and ste... more 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 (3 g-1). The typical dark-orange colonies which developed on LGIP agar plates were purified. Identification was performed with the API microtube systems: API 20E for Enterobacteriaceae and API 20NE for non-Enterobacteriaceae. API profiles of the local isolates were closely related to those of the type culture Gluconacetobacter diazotrophicus (ATTC 49037). The isolates successfully reduced C2H2 and produced appreciable amounts of ethylene in the presence of cane juice. This suggested that the local isolates are closely related to the type strain G. diazotrophicus. Wheat seedlings were inoculated with a number of isolates under gnotobiotic conditions. Both optical and scanning electron microscopy showed that endophytic Gluconacetobacter spp. were present in all the samples tested. They were observed in apparently intact and enlarged epidermal root cells, and also in stem tissues, indicating that the bacterium was able to migrate upward into the shoot tissues. Although Gluconacetobacter inoculation did not stimulate the growth of the cereal plant, the results obtained are particularly interesting because this bacterial species was capable of colonizing the internal tissues of wheat, not considered a natural host until now.