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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-synthesized Ag NPs was in vitro tested against myco-toxigenic Penicillium gresiofulvum. The bio-fabrication of well characterized Ag NPs was proved in this study. Growth of P. gresiofulvum was successfully suppressed following the bio-Ag NPs treatments. It could be concluded that mycosynthesizer of Ag NPs could be found along with the plant pathogenic fungi in the same situ. Utilization of such finding is required to find out an alternative control method for phytopathogenic and/or mycotoxigenic fungi. [ABSTRACT FROM AUTHOR]

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 Ag NPs were also checked in the Cladosporium sphaerosporium. The X ray diffraction (XRD), Energy Dispersive Spectroscopy (EDS), Transmission Electron Microscopy (TEM), and Optical absorption measurements were confirmed the bio-synthesis of Ag NPs. The in vitro antifungal activity test of bio-synthesized Ag NPs was also proved in this study. [ABSTRACT FROM AUTHOR]

Sodium and potassium silicates were in it evaluated against seven a i m 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 growth of the tested isolates was strongly inhibited by both silicates. Varied morphological changes in a i m mycelia following silicate treatments were observed including; asymmetric mycelium compared with the control. Silicate-treated cultures of a i m species were generally characterized by wizened mycelia, curling, twisting, and distorted hyphae. Diameter of silicate treated hyphae of a i m species was generally smaller than the control. Promising antifungal activity of potassium and sodium silicates in it ; suggest that phytopathogenic species of a i m could be controlled by both materials. Further researches are needed in order to confirm the in i effects of such materials and identify the optimal effective doses. [ABSTRACT FROM AUTHOR]

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 outdoor pot experiments over two seasons. Significant reductions in disease incidence and severity were achieved by those antioxidants compared with the control, particularly after two and three sprays. Punch C fungicide and thiourea were the best compounds in reducing disease incidence and severity followed by benzoic and salicylic acid. Two and three sprays of the tested compounds increased the seed weight, straw weight, and number of capsules per plant compared with the control over seasons. These results may be due to the potential of the tested antioxidants to promote plant productivity and profitability. Therefore, these antioxidants have potential in suppressing flax Powdery mildew and may be alternatives to synthetic fungicides. [ABSTRACT FROM AUTHOR]

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 the predominant fungus, A. niger, to produce oxalic acid was evaluated using high-performance liquid chromatography. About 50% of the tested A. niger isolates produced oxalic acid; the amount produced was in the range of 90-550 ppm of oxalic acid. Because A. niger was the predominant and most widely distributed toxigenic fungus in the examined samples, more efforts should be directed to minimize the risk of oxalic acid contamination of commoditized coffee beans in the Kingdom of Saudi Arabia [ABSTRACT FROM AUTHOR]

The pathogenicity of eight isolates of Rhizoctonia solani from 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 isolate interaction were always non-significant sources of variation in all the tested parameters. The isolate was always a highly significant (P=0.000) source of variation in all the tested parameters. The results of the ANOVA in the present study suggest that physiologic specialization did not occur within R. solani isolates pathogenic on cotton. They also imply that resistance of the tested cultivars was only horizontal, and there were no significant differences among cultivars in this type of resistance. Similarly, pathogenicity of the tested isolates was only aggressiveness, and the isolates significantly differed in this type of pathogenicity. A hierarchical cluster analysis was conducted in order to group the isolates according to disease variables measured on the tested cultivars. Cluster analysis divided the isolates into groups; however, grouping the isolates was not related to their AGs. [ABSTRACT FROM AUTHOR]

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 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), G1 (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 myco-pollutants. [ABSTRACT FROM AUTHOR]

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 per billion (ppb). The highest amount of aflatoxin B1 (8ppb) was produced by A. flavus isolated from corn grains. The sorghum isolate of Penicillium oxalicum was the highest producer of citreoviridin (37ppb). Fusarium subglutinans isolate recovered from popcorn was capable. of producing fumonisin B1, zearalenone and vomitoxin (DON). Corn isolate of Fusarium proliferatum however, failed to produce fumonisin B1 and sorghum isolate of Fusarium verticillioides produced only fumonisin B1. The antifungal activity of yellow liquid fraction of Aloe vera against toxigenic fungi was tested. All tested concentrations were effective in inhibiting fungal growth. [ABSTRACT FROM AUTHOR]

Antifungal activity of extracts of cinnamon (Cinnamomum zeylanicum), Cloves (Syzygium aromaticum), ginger (Zingiber officinale) and turmeric (Curcuma longa) were evaluated in vitro against 17 Penicillium spp . Seed disease and rotten fruit caused by these species cause considerable loss of quality for different agricultural products. Isolates of Penicillium spp. were screened for production of patulin an important serious mycotoxin. About 70.59% of Penicillium spp. produced this toxin in concentrations ranging from 4 to 31 ppb. The response of Penicillium spp. to plant extracts differed according to the plant extract and concentration. Cinnamon extract showed the greatest effect on P. asperosporum, P. aurintogriseum and P. brevicompactum , and cloves extract produced the greatest effect on P. chermesinum and P. duclauxii . Turmeric extract had less effect on P. duclauxii . Cloves extract was the most effective in reducing the growth of Penicillium spp . On the other hand, ginger extract with all concentrations used had less effect against most Penicillium spp in the laboratory. Plant extracts are promising as natural sources of environmentally friendly compounds in laboratory studies., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 Published by Elsevier B.V. on behalf of King Saud University.)

The present study describes the biosynthesis of silver nanoparticles, using the fungus Penicillium verrucosum . The silver nanoparticles were synthesised by reacting silver nitrate (AgNO 3 ) with the cell free filtrates of the fungal culture, and were then characterized by UV-visible spectroscopy, transmission electron microscopy, scanning electron microscopy, energy-dispersive, and X-ray diffraction analysis to further evaluate their successful biosynthesis, optical and morphological features (size and shape), and crystallinity. The bioactivity of the synthesized nanoparticles against two phytopathogenic fungi i.e: Fusarium chlamydosporum and Aspergillus flavus was evaluated using nanomaterial seeding media. These biogenic silver nanoparticles were polydisperse in nature, with a size of 10-12 nm. With regard to the antifungal activity, 150 ppm of the nanoparticles suppressed the growth of F. chlamydosporum and A. flavus by about 50%. To the best of our knowledge, this is the first report on the use of P. verrucosum to synthesise silver nanoparticles. The present study demonstrates a novel, simple, and eco-friendly process for the generation of biofunctionally useful biogenic nanoparticles., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 Published by Elsevier B.V. on behalf of King Saud University.)

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 leaves of Avicennia marina (77 isolates), sediment (15), seawater (10) and decaying thalli of Sargassum (6). Of the 108 isolates, three strains (SY25, SY38 and SY52) were selected based on their high biomass productivity and high percentages of PUFAs. Phylogenetic analyses based on 18S rDNA placed the three strains within the Aurantiochytrium clade with high statistical support. Species of Aurantiochytrium formed six separate clades, the two strains (SY38 and SY52) formed a separate clade that is a sister clade to the one that contains the type species A . limacinum , while SY25 grouped with Aurantiochytrium sp. TA4, that is also isolated from mangroves in Iran, Arabian Gulf. The strains (SY38 and SY52) shared the phylogenetic placement, their morphology and fatty acid profile. The strain SY25 have different shape of sporangia that divide to give zoospores directly, sporogenous cells are surrounded by thick gelatinous sheath and produce high levels of Linoleic and Oleic essential unsaturated fatty acids. The three studied strain produced high levels of Palmitic acid (ranged between 31.1 and 65.3 % of total fatty acids) that can be further optimized for biofuel production., (© 2020 Published by Elsevier B.V. on behalf of King Saud University.)

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 were characterized and confirmed in different ways. X ray diffraction (XRD), Energy Dispersive Spectroscopy (EDS), Transmission Electron Microscopy (TEM) and optical absorption measurements confirmed the bio-synthesis of Ag NPs. The in vitro antifungal investigation showed that biosynthesized Ag NPs were capable of inhibiting the growth of aflatoxigenic A. flavus var. columnaris . Utilization of plant pathogenic fungi in the Ag NPs biosynthesis as well as the use of bio-Ag NPs to control fungal plant diseases instead of chemicals is promising. Further work is needed to confirm the efficacy of the bio-Ag NPs against different mycotoxigenic fungi and to determine the potent applicable doses.