Myco-fabricated silver nanoparticle by novel soil fungi from Saudi Arabian desert and antimicrobial mechanism.

Biological agents are getting a noticeable concern as efficient eco-friendly method for nanoparticle fabrication, from which fungi considered promising agents in this field. In the current study, two fungal species (Embellisia spp. and Gymnoascus spp.) were isolated from the desert soil in Saudi Arabia and identified using 18S rRNA gene sequencing then used as bio-mediator for the fabrication of silver nanoparticles (AgNPs). Myco-synthesized AgNPs were characterized using UV-visible spectrometry, transmission electron microscopy, Fourier transform infrared spectroscopy and dynamic light scattering techniques. Their antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae were investigated. In atrial to detect their possible antibacterial mechanism, Sodium dodecyl sulfate (SDS-PAGE) and TEM analysis were performed for Klebsiella pneumoniae treated by the myco-synthesized AgNPs. Detected properties of the fabricated materials indicated the ability of both tested fungal strains in successful fabrication of AgNPs having same range of mean size diameters and varied PDI. The efficiency of Embellisia spp. in providing AgNPs with higher antibacterial activity compared to Gymnoascus spp. was reported however, both indicated antibacterial efficacy. Variations in the protein profile of K. pneumoniae after treatments and ultrastructural changes were observed. Current outcomes suggested applying of fungi as direct, simple and sustainable approach in providing efficient AgNPs.

Keratinases Produced by Aspergillus stelliformis, Aspergillus sydowii, and Fusarium brachygibbosum Isolated from Human Hair: Yield and Activity.

Twenty fungal strains belonging to 17 species and isolated from male scalp hair were tested for their capacity to hydrolyze keratinous material from chicken feather. The identification of the three most efficient species was confirmed by sequencing of the internal transcribed spacer (ITS) region of rDNA. Activities of fungal keratinases produced by Aspergillus stelliformis (strain AUMC 10920), A. sydowii (AUMC 10935), and Fusarium brachygibbosum (AUMC 10937) were 113, 120, and 130 IU mg-1 enzymes, respectively. The most favorable conditions were at pH 8.0 and 50 °C. Keratinase activity was markedly inhibited by EDTA and metal ions Ca+2, Co+2, Ni+2, Cu+2, Fe+2, Mg+2, and Zn+2, with differences between the fungal species. To the best of our knowledge, this is the first study on the activity of keratinase produced by A. stelliformis, A. sydowii, and F. brachygibbosum. F. brachygibbosum keratinase was the most active, but the species is not recommended because of its known phytopathogenicty. Aspergillus sydowii has many known biotechnological solutions and here we add another application of the species, as producer of keratinases. We introduce A. stelliformis as new producer of active fungal keratinases for biotechnological solutions, such as in the management of keratinous waste in poultry industry.

Effect of sampling time on the heavy metal concentrations of brown algae: A bioindicator study on the Arabian Gulf coast.

Macroalgae have often been studied as bioindicators for heavy metal pollution on sea coasts including the Arabian Gulf. On the Arabian Gulf coasts, heavy metals are continuously being released by industrial activities and therefore, pollution monitoring is needed. Biomonitoring studies using macroalgae has given highly different assessments due to the variability in algal species and sampling time points. We carried out a systematic monthly sampling of brown algae (Phaeophyta) from three locations on the western coast of the Arabian Gulf between September and February 2018. One urban area (Uqair) and two oil refining areas (Ras Tanura and Jubail) were monitored due to they have a common brown macroalgae species composition. The incidence of Cystoseira myrica, C. trinodis C. osmundacea, Hormophysa cuneiformis, Sargassum aquifolium, S. latifolium, S. filipendula and Padina boryana varied among the sites and with the time of year within the sites. The concentrations of Co, Cd and Pb varied among the sampling sites, the algal species and the sampling time points remarkably. A tentative time-trend increasing towards February was observed for some species. However, it appeared that neither optimum sampling time point, nor superior brown algae species could be recommended. The highest heavy metal accumulation was observed in Padina boryana. However, this species grew only on the two oil polluted sites. We concluded that some brown algae species can be used for biomonitoring heavy metal pollution on the western coast of the Arabian Gulf. The species incidence should be monitored systematically and the species used should be chosen locally and sampled at the same time of the year.

Microbial Diversity of Some Sabkha and Desert Sites in Saudi Arabia.

Several studies isolated fungal and bacterial species from extreme environments, such as Sabkha and hot deserts, as their natural habitat, some of which are of medicinal importance. Current research aimed investigating the microbial (fungi and bacteria) diversity and abundance in Sabkha and desert areas in Saudi Arabia. Soil samples from nine different geographical areas (Al-Aushazia lake, AlQasab, AlKasar, Tabuk, Al-Kharj, Al-Madina, Jubail, Taif and Abqaiq) were collected and cultured for microbial isolation. Isolated fungi and bacteria were identified by molecular techniques (PCR and sequencing). Based on 18S rDNA sequencing, 203 fungal species belonging to 33 genera were identified. The most common fungal genera were Fusarium, Alternaria, Chaetomium, Aspergillus Cochliobolus and Pencillium, while the most common species were Chaetomium globosum and Fusarium oxysporum. By 16S rDNA sequencing 22 bacterial species belonging to only two genera, Bacillus and Lactobacillus, were identified. The most commonly isolated bacterial species were Bacillus subtilis and Lactobacillus murinus. Some fungal species were confined to specific locations, such as Actinomyces elegans, Fusarium proliferatum, Gymnoascus reesii and Myzostoma spp. that were only isolated from Al-Aushazia soil. AlQasab soil had the highest microbial diversity among other areas with abundances of 23.5% and 4.4% of total fungi, and bacteria, respectively. Findings of this study show a higher degree of fungal diversity than that of bacteria in all studied areas. Further studies needed to investigate the connection between some isolated species and their habitat ecology, as well as to identify those of medicinal importance.

Microbiological and molecular identification of bacterial species isolated from nasal and oropharyngeal mucosa of fuel workers in Riyadh, Saudi Arabia.

This study aimed to determine the bacterial species colonizing the nasal and oropharyngeal mucosa of fuel workers in Central Riyadh, Saudi Arabia on a microbiological and molecular level. Throat and nasal swab samples were obtained from 29 fuel station attendants in the period of time extending from March to May 2014 in Riyadh, Saudi Arabia. Microbiological identification techniques were utilized to identify the bacterial species isolated. Antibiotic sensitivity was assessed for each of the bacterial isolates. Molecular identification techniques based on PCR analysis of specific genomic sequences was conducted and was the basis on which phylogeny representation was done for 10 randomly selected samples of the isolates. Blood was drawn and a complete blood count was conducted to note the hematological indices for each of the study participants. Nineteen bacterial species were isolated from both the nasal cavity and the oropharynx including Streptococcus thoraltensis, alpha-hemolytic streptococci, Staphylococcus hominis, coagulase-negative staphylococci, Leuconostoc mesenteroides, Erysipelothrix rhusiopathiae and several others. We found 100% sensitivity of the isolates to ciprofloxacin, cefuroxime and gentamicin. Whereas cefotaxime and azithromycin posted sensitivities of 85.7% and 91.4%, respectively. Low sensitivities (<60% sensitivity) to the antibiotics ampicillin, erythromycin, clarithromycin and norfloxacin were observed. Ninety-seven percent similarity to the microbial bank species was noted when the isolates were compared to it. Most hematological indices recorded were within the normal range. In conclusion, exposure to toxic fumes and compounds within fuel products may be a contributing factor to bacterial colonization of the respiratory tract in fuel workers.

Molecular identification of isolated fungi from stored apples in Riyadh, Saudi Arabia.

Fungi causes most plant disease. When fruits are stored at suboptimal conditions, fungi grows, and some produce mycotoxin which can be dangerous for human consumption. Studies have shown that the Penicillium and Monilinia species commonly cause spoilage of fruits, especially apples. Several other genera and species were reported to grow to spoil fruits. This study was conducted to isolate and identify fruit spoilage by fungi on apples collected in Riyadh, Saudi Arabia and conduct a molecular identification of the fungal isolates. Thus, we collected 30 samples of red delicious and Granny Smith apples with obvious spoilage from different supermarkets between February and March of 2012 in Riyadh, Saudi Arabia. Each apple was placed in a sterile plastic bag in room temperature (25-30 °C) for six days or until fungal growth was evident all over the sample. Growth of fungal colonies on PDA was counted and sent for molecular confirmation by PCR. Six fruit spoilage fungi were isolated, including Penicillium chrysogenum, Penicillium adametzii, Penicillium chrysogenum, Penicillium steckii, Penicillium chrysogenum, and Aspergillus oryzae. P. chrysogenum was the most frequent isolate which was seen in 14 of a total of 34 isolates (41.2%), followed by P. adametzii and A. oryzae with seven isolates each (20.6%) and the least was P. steckii with six isolates (17.6%). Penicillium species comprised 27 of the total 34 (79.4%) isolates. Sequence analysis of the ITS regions of the nuclear encoded rDNA showed significant alignments for P. chrysogenum, P. adametzii and A. oryzae. Most of these fungal isolates are useful and are rarely pathogenic; however they can still produce severe illness in immune-compromised individuals, and sometimes otherwise healthy people may also become infected. It is therefore necessary to evaluate the possible production of mycotoxins by these fungi to determine a potential danger and to establish its epidemiology in order to develop adequate methods of control.

The effect of mycotoxins found in some herbal plants on biochemical parameters in blood of female albino mice.

In this study, twenty five samples ofwell-known herbs in Riyadh, Saudi Arabia were collected and analyzed for Total Fungi Count (TFC). Mycotoxins were extracted and screened using SMKY liquid medium. One hundred and thirty adult female albino mice were grouped into three wherein one group (n = 110) was fed with an aqueous extract from herbal plants. The second group (n = 15) was fed with an aqueous extract of the isolated fungal species. The third group comprised the control group which was given water only (n = 5). All mice were fed with mice breeding diet by Pillsbury, UK. After 5 weeks, mice were fasted and blood was withdrawn for biochemical analysis including alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyltransferase (GGT), serum creatinine and urea. Calligonum comosum with 2 x 10(5) cfu g(-1) fungus spore, grained mixed herbs (24 x 10(3) cfu g(-1)) and Salvia officinalis (23 x 10(3) cfu g(-1)) were the most contaminated samples. The genus Aspergillus was the most dominant genus recovered (142 isolates) followed by Penicillium (14 isolates) and these two genera were found in 85.0 and 11.0% of the samples analyzed. Aspergillus fumigatus, Aspergillus flavus and Aspergillus ochraceus were the most dominant and frequently isolated (47.3, 46.5 and 18.1%, respectively), followed by Aspergillus citrinum (11.0%). Aspergillus ochraceus had 21.7 microg kg(-1) of Aflatoxin B2 and 7.25 microg kg(-1) of ochratoxin A, whereas Aspergillus flavus had 7.45 microg kg(-1) of Aflatoxin B2 and Aspergillus fumigatus had 3.5 microg kg(-1) of Aflatoxin B2 and 3.8 microg kg(-1) of ochratoxin A. Mean creatinine, urea, ALT, AST and GGT were higher in mice fed or treated with herbal and fungal extracts group than the control group. This study confirms previous studies demonstrating the predominance of Aspergillus species in herbal and medicinal plants and its capability in the production of aflatoxin with induction of nephrotoxicity and hepatoxicity in animals and even in humans.