National Research Central Laboratory

Saudi Arabia

National Research Central Laboratory

Saudi Arabia

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El-Samawaty A.E.I.-R.M.A.,King Saud University | El-Samawaty A.E.I.-R.M.A.,Agricultural Research Center | Bahkali A.H.A.,King Saud University | Abd-Elsalam K.,Agricultural Research Center | And 5 more authors.
Fresenius Environmental Bulletin | Year: 2012

Airborne Aspergillus species were surveyed in outdoor environment of Riyadh city using mechanical air sampling technique. Anatoxin 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 twenty five Aspergillus species obtained, A. niger and A. flavus were the most predominant ones. A. niger, A. flavus and E. nidulans were also highly distributed species over the sites. Surveyed Aspergillii varied in their ability to produce aflatoxins. Thus, although some species were aflatoxigenic, others exhibited no detectable toxin production. Aspergillus flavus was the highest producer of B1 (6.6 ppb), G 1 (3.82 ppb) and G2 (2.82 ppb) aflatoxins. Further information on genera, species and spore density in the air are limiting factors required for assessing any adverse effects of outdoor mycopollutants. © by PSP.


Bahkali A.,King Saud University | El-Samawaty A.E.-R.M.A.,King Saud University | El-Samawaty A.E.-R.M.A.,Egyptian Plant Pathology Research Institute | Yassin M.A.,King Saud University | And 5 more authors.
Journal of Pure and Applied Microbiology | Year: 2013

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 most predominant, with highest distribution over samples. Significant to highly significant positive correlation was found among some isolated fungi. Most oí Aspergillus flavus isolates were capable of producing sterigmatocystin, maltoryzine and aflatrem. Meanwhile, all tested isolates of Aspergillus niger were capable of producing oxalic acids ranged from 300-850 mg/ml in the culture media. Both of Fusarium proliferatum and Fusarium subglutinans were toxigenic and varied in their productivities of ipomeanine, neosolaniol, nivalenol and NT-2 toxin. In respect to citrinin and citreovirdin, Pénicillium aurantiogriseum was more productive than Pénicillium brevicompactum.


El-Samawaty A.E.-R.M.A.,Egyptian Plant Pathology Research Institute | El-Samawaty A.E.-R.M.A.,King Saud University | El-Naggar M.A.,Egyptian Plant Pathology Research Institute | El-Naggar M.A.,National Research Central Laboratory | And 4 more authors.
Journal of Pure and Applied Microbiology | Year: 2014

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 generally the most predominant fungus with isolation frequency range of 20.95% to 73.17%. Mycotoxin analysis were performed by high performance liquid chromatography (HPLC). HPLC analysis of cottonseed revealed the presence of mycotoxins that were varied according to storage periods and genotypes. Significant correlations between the frequency of isolated fungi and the mycotoxin production was recorded in this study. Seven models were constructed using the predictors supplied by stepwise regression with R2 values ranged from 0.433 to 0.578%. Since the stepwise multiple regression was effectively constructed 7 predictive models; this study suggested that the contents of some mycotoxins in cotton seeds could be predicated depending on the fungal isolation frequencies.


El-Samawaty A.E.-R.M.A.,King Saud University | El-Samawaty A.E.-R.M.A.,Egyptian Plant Pathology Research Institute | Omar M.R.,Egyptian Plant Pathology Research Institute | El-Naggar M.A.,Egyptian Plant Pathology Research Institute | And 4 more authors.
Journal of Plant Sciences | Year: 2012

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 the same cultivar. The occurrence of damping off was dependent upon cultivars responsibility and the virulence of isolate used. It was also found that some tested isolates i.e., Fusarium moniliforme isolate No. 11, Fusarium semitectum isolate No. 20, Macrophomina phaseolina isolate No. 25, Penicillium isolate No. 30 and all tested isolates of Rhizoctonia were capable of infecting all tested cultivars. Tested isolates of Macrophomina phaseolina were highly virulent against different cotton cultivars. © 2012 Academic Journals Inc.


Yassin M.A.,King Saud University | Yassin M.A.,Egyptian Plant Pathology Research Institute | El-Samawaty A.E.-R.M.A.,King Saud University | El-Samawaty A.E.-R.M.A.,Egyptian Plant Pathology Research Institute | And 3 more authors.
Journal of Pure and Applied Microbiology | Year: 2013

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 productivities of the isolated fungi were analyzed using HPLC. Nine fungal species belonging to five genera were found to be associated with pistachio nut samples. Distributions of isolated fungi indicated that Aspergillus niger, Rhizopus sp. and A. flavus were predominant with isolation frequencies of 67.7%, 57.5% and 32.5% respectively. Highly significant positive and negative correlations were observed among some fungal species when compared with the frequency of the others. The mycotoxins; Aflatrem, maltoryzine and sterigmatocystin were produced by 60%, 40% and 60% of the A. flavus isolates in this study. Meanwhile, 50% of the tested A. niger isolates were oxalic acids producers. Neither citrinin nor citreoviridin could be produced by any of the tested Penicillium spp. in this study.


Yassin M.A.,King Saud University | Yassin M.A.,Egyptian Plant Pathology Research Institute | El-Samawaty A.M.A.,King Saud University | El-Samawaty A.M.A.,Egyptian Plant Pathology Research Institute | And 3 more authors.
Life Science Journal | Year: 2013

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 Riyadh, Kingdom of Saudi Arabia. Aspergillus flavus, A. niger, A. ochraceus, A. ustus, Chaetomium globosum, Penicillium aurantiogriseum, Phoma sp. Rhizopus sp. and Ulocladium atrum were isolated. A. niger was the most predominant while, C. globosum was the least frequent species. Significant positive and negative correlations were found among isolation frequencies of some isolated fungal species. About 40% of A. flavus isolates produced aflatrem (2-3 ppb), while 60% were sterigmatocystin (300-440 ppb) and maltoryzine (7-10 ppb) producers. Meanwhile, 57% of A. niger isolates were capable of producing oxalic acids (47-430 mg/ml). On the other hand, 60% of P. aurantiogriseum isolates were citrinin producers (5-22 ppb) and 40% were citrovirdin producers (20-45 ppb). Due to the ideal nutrient composition of almond, as well as inappropriate processing and storage conditions, the risk of fungal and mycotoxin contamination could be increased. To avoid almond contamination with toxigenic fungi, and prevent hazards to human and animal health; rigorous quarantine, accurate diagnosing methods and healthy storage conditions should be undertaken.

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