Abd El-Rahim El-Samawaty

Abd El-Rahim El-Samawaty
King Saud University | KKUH · Department of Botany and Microbiology

PhD

About

53
Publications
17,170
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
565
Citations
Citations since 2017
6 Research Items
366 Citations
20172018201920202021202220230204060
20172018201920202021202220230204060
20172018201920202021202220230204060
20172018201920202021202220230204060
Additional affiliations
February 2009 - present
King Saud University
Position
  • Professor (Assistant)
May 1995 - February 2009
Agricultural Research Center, Egypt
Position
  • Professor (Associate)

Publications

Publications (53)
Article
Full-text available
This study explores low-cost substrates for the production of high biomass, lipid and DHA by local native strain of thraustochytrid that was isolated from decaying leaves of Avicennia marina collected from Yanbu mangroves along the Red Sea coast of Saudi Arabia. Molecular phylogenetic analyses based on 18S rDNA sequences placed the thraustochytrid...
Article
Full-text available
The present study describes the biosynthesis of silver nanoparticles, using the fungus Penicillium verrucosum. The silver nanoparticles were synthesised by reacting silver nitrate (AgNO3) with the cell free filtrates of the fungal culture, and were then characterised by UV-visible spectroscopy, transmission electron microscopy, scanning electron mi...
Article
Full-text available
This is the first report of thraustochytrids from Saudi Arabia. A total of 108 isolates of thraustochytrid were cultured from Syhat mangroves, Arabian Gulf, Saudi Arabia. Isolated thraustochytrids belonged to five genera: Aplanochytrium, Aurantiochytrium, Schizochytrium, Thraustochytrium and Ulkenia. Cultured thraustochytrids isolated from decaying...
Article
Strain SY-07 was isolated from decaying leaves of Avicennia marina collected from Syhat mangroves, Dammam city, Arabian Gulf, Saudi Arabia. Phylogenetic analyses of three genes [D1/D2 region of the LSU and SSU rRNA genes and internal transcribed spacer (ITS) region] showed that strain SY-07 represents a novel species of the genus Saturnispora disti...
Article
Full-text available
During an ongoing study of marine fungi from Saudi Arabia, an undescribed taxon was recorded on driftwood collected from intertidal zone at El Khobar sea front, Dammam city, Saudi Arabia. A new taxon, Khaleijomyces, is described in here as a new genus and a new species, K. marinus is established. Phylogenetic analyses of a combined SSU and LSU rDNA...
Article
Full-text available
Sorghum grain contaminant, Phoma leveillei was evaluated in the present study for silver nanoparticles (Ag NPs) biosynthesis. X ray diffraction (XRD), Energy Dispersive Spectroscopy (EDS), Transmission Electron Microscopy (TEM), and Optical absorption measurements, were all used to characterize and confirm the bio-synthesis of Ag NPs. Bio-synthesiz...
Article
Full-text available
The bio-synthesis of silver nanoparticles (Ag NPs) was investigated using non-toxigenic isolate of Aspergillus clavatus. The fungus used in this study was seed borne and isolated from popcorn grains. Identification and characterization of biosynthesized Ag NPs were achieved by the aid of spectroscopic techniques. The antifungal properties of such A...
Article
Full-text available
This work was conducted to evaluate the ability of grape molding fungus; Penicillium citrinum to synthesize silver nanoparticles (Ag NPs). The potency of biosynthesized Ag NPs was checked against the aflatoxigenic Aspergillus flavus var. columnaris, isolated from sorghum grains. Biosynthesized Ag NPs was characterized and confirmed in different way...
Article
Full-text available
Aspergillus flavus is one of the most abundant and widely distributed fungi on earth. A. flavus produces aflatoxins (AFs), which are toxic secondary metabolites. AFs have harmful effects on public health (humans and animals) and agricultural crops. Inter-simple sequence repeat (ISSR) markers were used to analyze the genetic diversity of 30 A. flavu...
Article
Full-text available
Sodium and potassium silicates were in vitro evaluated against seven Fusarium species; causing cotton seedling damping-off. Scanning electron microscopy-SEM was used to investigate the morphological changes in the fungal hyphae. All collected data were statistically analyzed, and the least significant difference was used to compare means. Mycelial...
Article
Full-text available
Five antioxidants; ascorbic acid, benzoic acid, citric acid, salicylic acid, and thiourea along with Punch C fungicide were evaluated against flax powdery mildew disease. Efficacy of foliar sprays of these compounds on disease incidence, disease severity, seed weight/plant, straw weight/plant and number of capsules/plant were investigated in an out...
Article
Silver nanoparticles have a high antimicrobial activity and are broadly utilized for several disinfection purposes including water and materials' sanitization for medical purposes. There have been comparatively few studies on using silver against plant pathogenic fungi. In this study, silver nanoparticles (Ag NPs) were used at concentrations of 0.0...
Article
Full-text available
Silver nanoparticles have a high antimicrobial activity and are broadly utilized for several disinfection purposes including water and materials’ sanitization for medical purposes. There have been comparatively few studies on using silver against plant pathogenic fungi. In this study, silver nanoparticles (Ag NPs) were used at concentrations of 0.0...
Article
Aspergillus species are regularly involved in human broncho-pulmonary diseases, mainly in immunocompromised patients. The essential oils extracted from three different plants were tested for their inhibitory effect on the growth of five pathogenic Aspergilli including Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus versico...
Article
Full-text available
Coffee bean-contaminating fungi were determined in random samples collected in Riyadh, Kingdom of Saudi Arabia, using the direct plating technique. Forty-five samples were examined and 12 fungal species belonging to 5 genera were isolated. Aspergillus niger was the most widely distributed and most frequently isolated fungus (86.67%). The ability of...
Article
Full-text available
Cinnamon (Cinnamomum zeylanicum), clove (Syzygium aromaticum), garlic (Allium sativum) and ginger (Zingiber officinale) extracts were in vitro evaluated against eight Rhizoctonia solani anastomosis groups AGs causing cotton seedlings damping-off. Experimental results were statistically analyzed and the least significant difference was used to compa...
Article
Full-text available
Mycological survey of associated fungi with common bean (Phaseolus vulgaris) and cowpea (Vigna unguiculata) seed samples, collected from markets throughout the Riyadh region of Saudi Arabia, was investigated. Frequencies of the isolated fungi were statistically compared. Seventeen and sixteen species belonging to eleven genera were isolated from co...
Article
Full-text available
Cottonseed borne fungi were isolated from five cotton (Gossypium barbadense L.) cultivars; Giza-80, Giza-86, Giza-88, Giza-90 and Giza-92. Alternaria spp., Aspergillus flavus, A. niger, Aspergillus spp. Fusarium spp., Penicillium spp., Rhizopus stolonifer and Trichoderma spp. were occurred in both non-strilized and sterilized seeds. A. niger was ge...
Article
Full-text available
Forty cashew nut samples randomly collected from Riyadh, kingdom of Saudi Arabia was surveyed using the direct plating technique. The mycological investigation revealed that seventeen fungal species belonging to 11 genera were isolated. Aspergillus niger was generally the most distributed and the most frequent fungus. Mycotoxin production ability o...
Article
Full-text available
The pathogenicity of eight isolates of Rhizoctonia solaniîrom different anastomosis groups was evaluated on five cotton (Gossypium barbadense L.) cultivars under greenhouse conditions. Damping-off, plant height and fresh weight were used as criteria to evaluate pathogenicity. Analysis of variance (ANOVA) showed that the cultivar and cultivar x isol...
Article
Full-text available
The aim of the present work was to survey the myco-contaminants associated with pistachio nut consumed in Riyadh, Kingdom of Saudi Arabia. A total of forty commercially available samples, randomly collected from different locations were investigated and the isolation frequencies of myco-contaminants were statistically analyzed. Mycotoxins productiv...
Article
In view of the ecological hazards of fungicides, a greenhouse study was conducted to determine the efficiency of seven Bacillus isolates against 32 isolates of Macrophomina phaseolina. Bacillus isolates, M. phaseolina isolates, and their interaction were all highly significant sources of variation in infection (damping-off), plant height, and dry w...
Article
Full-text available
The antifungal activity of 4 plant extracts from cinnamon (Cinnamomum zeylanicum), clove (Syzygium aromaticum), garlic (Allium sativum) and ginger (Zingiber officinale) was in vitro evaluated against 10 Fusarium spp. causing cotton seedlings damping-off. The pathogenicity of such Fusarium spp. on cotton seedlings was confirmed using soil infestatio...
Article
Full-text available
The myco-contaminants associated with almond seeds were surveyed and the fungal isolation frequencies were statistically analyzed. HPLC was used to assess the mycotoxins production of some involved fungi. Nine species belonging to six fungal genera were recovered from a total of 20 random samples of almond collected from different locations in Riya...
Article
Full-text available
Ten resistance elicitors, ammonium tartrate, ascorbic acid, benzoic acid, citric acid, cinnamic acid, hydroquinone, salicylic acid, sodium citrate, sodium metabisulfate and thiourea, were applied as foliar sprays using two methods at concentrations of 200 ppm to evaluate their capabilities to induce resistance in the flax cultivar Sakha 1 against r...
Article
Full-text available
Contamination of grapes by mycotoxins due to Penicillium infection is one of the most causes of human toxicoses. To minimize the risk of mycotoxin exposure, Allium sativum was evaluated as anti-Penicillium. Five isolates representing 4 species namely Penicillium citrinum, P. expansum, P. puberulum and P. verrucosum were investigated. Mycotoxin prod...
Article
Full-text available
Mycoflora associated with 120 walnut samples was examined using agar plate method. Data of isolation frequency were statistically analyzed. Mycotoxin productivity of obtained fungi was assayed using HPLC. Twelve species belonging to six fungal genera were isolated in this work. Aspergillus flavus, Aspergillus niger and Rhizopus stolonifer were the...
Article
Toxin producing fungi are potentially affecting human and animal health and should be eradicated. Toxigenicity of thirteen sorghum gain molding fungi belonging to Aspergillus, Fusarium and Penicillium species was evaluated in this study using HPLC. Potential of garlic (Allium sativum) juice for controlling these fungi was also examined in vitro. Ob...
Article
Full-text available
Mycotoxin production and pathogenicity of Penicillium spp. involved in apple blue mold were investigated. Twenty four isolates representing nine species recovered from blue moldy apple samples were used. Mycotoxin production of these isolates was assayed using HPLC. Statistical analysis of pathogenicity test was undertaken and LSD was used to compa...
Article
Full-text available
Antifungal activity of different concentrations of garlic (Allium sativum) juice was assessed against 24 Penicillium isolates representing 9 species namely Penicillium asperosporum, P. aurantiogriseum, P. canescens, P. citrinum, P. expansum, P. griseofulvum, P. puberulum, P. restrictum and P. verrucosum. Isolates used in this study were recovered f...
Article
Full-text available
To determine the involvement of seed born fungi in cotton seedlings damping-off, 39 isolates representing 13 species belonging to seven genera were isolated from seven cotton cultivars and tested on the same cultivars under greenhouse conditions. Obtained results showed that cotton seedling damping off was varied among cultivars as well as within t...
Article
Full-text available
To avoid fungicide risks, efficacy of Allium sativum was evaluated against corn grain rotting fungi. Mycotoxigenicity of tested fungi was also investigated using HPLC. All Aspergillus species were toxigenic except corn and popcorn isolates of Aspergillus clavatus as well as corn isolate of Aspergillus terreus. Highest Aflatoxin was produced by corn...
Article
Full-text available
Airborne Aspergillus species were surveyed in outdoor environment of Riyadh city using mechanical air sampling technique. Aflatoxin productivity rates of the obtained species were also investigated using HPLC. Aspergillii were the most predominant myco-pollutants of outdoor air in Riyadh city and intensively concentrated at Al-Murabba site. Among t...
Article
Full-text available
Field trials were conducted in 2008/2009 and 2009/2010 growing seasons at Giza Agricultural Research Station to evaluate powdery mildew (PM) severity on nine flax cultivars. Tested cultivars could be classified into five distinct groups, i.e., highly susceptible (Corland and C.I. 2008), susceptible (Giza 7 and Marshall), moderately susceptible (Cas...
Article
Full-text available
This study aimed to examine the antifungal properties of garlic juice against mycotoxigenic Aspergillus and Peni-cillium fungi associated with peanut. Plate technique with Potato Dextrose Agar (PDA) was used, and results were obtained by measuring diameters of fungal growth over incubation period. Mycotoxin productivity of tested fungi revealed tha...
Article
Full-text available
A simple, efficient, reliable and cost-effective method for isolation of total genomic DNA from fungi, suitable for polymerase chain reaction (PCR) amplification and other molecular applications was described. The main advantages of the method are: (1) does not require the use of liquid nitrogen for preparation of fungi DNA; (2) the mycelium is dir...
Article
Full-text available
Mycotoxigenic fungi isolated from corn, sorghum grains and peanut kernels were identified. Nine fungal species belonging to three genera were recovered from the tested samples. With the exception of the sorghum isolate, all tested Aspergillus flavus isolates were capable of producing variable amounts of G1 and B1 aflatoxin ranging from 1-6 parts pe...
Article
Full-text available
Two apple blue molding Penicellium species; Penicillium asperosporum (G. Smith) and Penicillium puberulum (Bain) were isolated for the first time in Saudi Arabia. Macro and micro morphological features along with mycotoxin productivity and pathogenic behavior were significant in characterization of these fungi. Mycotoxin productivity revealed that...
Article
Full-text available
A survey of fungi associated with corn and popcorn samples, collected from markets throughout the Riyadh region of Saudi Arabia, was investigated. Seventeen spe-cies belonging to nine genera were recovered from corn grains, while 11 species belonging to six genera were re-covered from popcorn grains. Frequencies of the isolated genera were statisti...
Article
Full-text available
Thirty one species belonging to 17 fungal genera were found to be associated with sorghum (Sorghum bicolor) grain samples imported to the Kingdom of Saudi Arabia. An agar plate method was used to screen 24 samples collected from different markets located in Riyadh region. Statistical comparisons of fungal isolation frequencies revealed that Aspergi...
Article
Full-text available
Fifty-two isolates of Rhizoctonia solani were isolated from cotton seedlings infected with postemergence damping-off disease, and obtained from cotton-producing areas in Upper Egypt governorates. Morphological characterization indicated that 13.46% of the isolates belonged to AG 2-2, 25% belonged to subgroup AG 4-HgI and 61.54% were AG 4-HgII. Fift...
Article
Pathogenicity of 21 isolates of Macrophomina phaseolina was tested on three cotton cultivars under greenhouse conditions. Analysis of variance (ANOVA) showed that the main effects of both isolates (P= 0.000) and cultivars (P = 0.000) were very highly significant sources of variation in post-emergence damping-off and survival. Isolate x cultivar int...
Article
A single-seed DNA extraction method was developed to extract high quality complex genomic DNA from different cotton tissues (leaves and seeds) as well as from mycelium of its fungal pathogens. Seeds were germinated in 24-well cell culture cluster and 5-days-old seedling tissue was used to extract DNA. The average yield of extracted DNA varied from...
Article
Full-text available
Pathogenicity of 21 isolates of Macrophomina phaseolina was tested on three cotton cultivars under greenhouse conditions. Analysis of variance (ANOVA) showed that the main effects of both isolates (P = 0.000) and cultivars (P = 0.000) were very highly significant sources of variation in post-emergence damping-off and survival. Isolate x cultivar in...
Article
Full-text available
A single-seed DNA extraction method was developed to extract high quality complex genomic DNA from different cotton tissues (leaves and seeds) as well as from mycelium of its fungal pathogens. Seeds were germinated in 24-well cell culture cluster and 5-days-old seedling tissue was used to extract DNA. The average yield of extracted DNA varied from...
Article
Full-text available
Twenty-nine isolates of Fusarium solani, originally isolated from diseased cotton roots in Egypt, were evaluated for their ability to cause symptoms on four genetically diverse cotton cultivars. Analysis of variance showed highly significant variance among cultivars, and isolates as well as the isolate × genotype interactions were highly significan...

Network

Cited By

Projects

Project (1)
Project
The goals of this self funding project is to address Green chemicals as a potential to control plant diseases, scaling up crop production along with higher quality . Minimize accumulation of heavy metals in the edible parts of plants irrigate with industrial and municipal contaminants found in irrigating water. Moreover, reduce the over dependence on the toxic pesticides . This work also integrated in solving the serious gab between the production of food and the explosive increase of population in the third world