Silver nanostructures prepared via novel green approach as an effective platform for biological and environmental applications

Silver nanoparticles play a significant role in biomedical sciences due to their unique properties allowing for their use as an effective sensing and remediation platform Herein, the green synthesis of silver nanostructures (Ag NSs), prepared via aqueous extract of waste Brassica oleracea leaves in the presence of silver nitrate solution (10-4 M), is reported. The Ag NSs are fully characterized and their efficacy with respect to 4-nitrophenol reduction, glucose sensing, and microbes is determined. Visually, the color of silver nitrate containing solution altered from colorless to yellowish, then reddish grey, confirming the formation of Ag NSs. HRTEM and SEAD studies revealed the Ag NSs to have different morphologies (triangular, rod-shaped, hexagonal, etc., within a size range of 20–40 nm) with face-centered cubic (fcc) crystal structure. The Ag NSs possess high efficacy for nitrophenol reduction (<11 min and degradation efficiency of 98.2%), glucose sensing (LOD: 5.83 µM), and antimicrobial activity (E. coli and B. subtilis with clearance zones of 18.3 and 14 mm, respectively). Thus, the current study alludes towards the development of a cost-effective, sustainable, and efficient three-in-one platform for biomedical and environmental applications

Molecular heterogeneity in the 18s DNA gene of Alternaria sp. and Fusarium sp. producing mycotoxins in rice and maize grains

Background: Food contaminated with fungi and their toxins is a problem that threatens many developing countries. Kingdom of Saudi Arabia depends on the exported grain and legume seeds. Materials and methods: The study involved examination of 160 samples of rice and maize seeds collected from different locations in the Kingdom of Saudi Arabia. Heterogeneity in the 18s rRNA gene of toxigenic Alternaria sp. and Fusarium sp. was unraveled. The seeds were disinfected and cultured on Potato Dextrose Agar (PDA), Yeast Extract Sucrose (YES) media and incubated at 25 °C/7 days. The isolated fungi were subjected to 18s rRNA gene sequencing. Five toxins were extracted from maize and rice grains infected with isolated fungi. Results: The isolated fungi were identified based on morphological and spores characters as Fusarium sp. and Alternaria sp. Molecular identification based on18s rDNA barcode' was performed due to its high degree of inter specific variability, conserved primer sites and multi-copy nature in the genome. Fusarium sp. produced the highest detected (2070 μg/kg) fumonisin especially in cereal production season 2011. The collected grain from Dammam recorded the highest percentage (5485.2 g/kg) of toxins. Conclusion: This work highlights that 50% of samples were found contaminated with toxins in various concentrations which impose a threat for public health and necessitate rapid identification methods for toxigenic fungi such as 18s rDNA sequencing. Keywords: Alternaria sp., Fusarium sp., Mycotoxins, PCR, 18s rDN

Molecular Identification of Streptomyces producing antibiotics and their antimicrobial activities

Five strains of Streptomyces, namely S, N, W, E and C (designations should be mentioned in detail here) isolated from the rhizosphere soil cultivated with palm Alajua (date, pressed dates), AlMedina city, Saudi Arabia, were induced to produce antibiotics. Antimicrobial activities were determined on solid medium supplemented with starch. The detection was based on the formation of transparent zones around colonies. The results indicated that isolates had antibacterial activities against Staphylococcus aureus, Bacillus cereus, B. subtilis, Pseudomonas aeruginosa and also showed antifungal activity against Candida albicans and Aspergillus niger. DNA extracted from five isolates was used as template for 16s rDNA gene amplification. The expected PCR size was 1.5 kbp;1.6 kbp; 1.25 kbp; 1.25kbp and 1.0 k bp for S, N, W, E and C isolates respectively using universal 16s rDNA gene primers using direct PCR. The isolates varied morphologically on the basis of spore color, aerial and substrate mycelium formation, and production of diffusible pigment. Isolates were tested under a microscope by using slide culture technique. The results indicate that the soil of this region is source of Streptomyces having antibacterial and antifungal activity and thus better utilization of these microorganisms as biological control agents

Impact of Moringa aqueous extract on pathogenic bacteria and fungi in vitro

Moringa peregrine have many benefits. In this study aqueous extract of Moringa plant inhibited the activity of these bacteria which include Bacillus cereus; Staphylococcus aureus; Pseudomonas aeruginosa, Klebsiella pneumonia, Escherichia coli; Enterococcus cloacae; Salmonella typhi and; Proteus vulgaris. Moringa extracts has shown an impact on the growth of bacteria on the Blood with inhibition zone variable (23.5 ± 0.45 to 12.5 ± 0.50 mm) according to the type of bacteria. The mean growth inhibition percentages were 85.9 ± 0.42 to 65.3 ± 0.34 nm against all tested bacteria. As regards to fungi, high potency extract displayed zones of inhibition of ⩾10 mm, moderate potent extracts gave zones of inhibition between <10 and 9 mm. The results indicated that, Moringa aqueous extract played variable antifungal activity ranged from high (18 ± 0.54 mm), moderate (13.2 ± 0.58 mm) and low (6.6 ± 0.47 mm). The inhibition zones diameter in millimeters against A. niger, A. flavus, P. italicum, F. oxysporum, R. stolonifer, Alternaria sp., C. albicans, C. parapsilosis were 15.2 ± 0.52, 12.4 ± 0.55, 10.5 ± 0.26, 9.4 ± 0.71, 13.2 ± 0.58, 6.6 ± 0.47, 12 ± 0.44 and 18 ± 0.54, respectively. On the other hand, the mean inhibition of growth (as percentages) were 75.2 ± 0.55, 59.4 ± 0.75, 58.2 ± 0.63, 46.5 ± 0.63, 62.5 ± 0.77, 24.5 ± 0.65, 20.3 ± 0.75 and 80.00 ± 0.70% respectively. Thus, the aqueous extract of Moringa leaves showed antimicrobial activity against tested bacteria, fungi and yeasts at different concentrations

Characterizing the Assemblage of Wood-Decay Fungi in the Forests of Northwest Arkansas

The study reported herein represents an effort to characterize the wood-decay fungi associated with three study areas representative of the forest ecosystems found in northwest Arkansas. In addition to specimens collected in the field, small pieces of coarse woody debris (usually dead branches) were collected from the three study areas, returned to the laboratory, and placed in plastic incubation chambers to which water was added. Fruiting bodies of fungi appearing in these chambers over a period of several months were collected and processed in the same manner as specimens associated with decaying wood in the field. The internal transcribed spacer (ITS) ribosomal DNA region was sequenced, and these sequences were blasted against the NCBI database. A total of 320 different fungal taxa were recorded, the majority of which could be identified to species. Two hundred thirteen taxa were recorded as field collections, and 68 taxa were recorded from the incubation chambers. Thirty-nine sequences could be recorded only as unidentified taxa. Collectively, the specimens of fungi collected in the forests of northwest Arkansas belong to 64 and 128 families and genera, respectively

In Vitro Studies on the Immunomodulatory Effects of Pulicaria crispa Extract on Human THP-1 Monocytes

Background. Pulicaria crispa (P. crispa) is a plant from the Compositae family that exhibits antioxidant, anti-inflammatory, antibacterial, and cytotoxic activities. Objective. The current study aimed at investigating the immunomodulatory effects of P. crispa extract in lipopolysaccharide- (LPS-) stimulated human monocytic THP-1 cells. Methods. To induce macrophage differentiation, THP-1 cell lines were treated with phorbol-12-myristate 13-acetate, followed by exposure to LPS with or without 50 or 100 μg/ml of P. crispa extract. The following tests were employed to test the immunomodulatory effects of the extract: MTT assay, ELISA, Western blotting analysis, cell migration and phagocytosis assays, and Annexin V staining method. Results. Exposure to 100 μg/ml P. crispa extract significantly reduced THP-1 cell proliferation, migration, and phagocytosis (in LPS-stimulated cells, but not in unstimulated cells). Moreover, the extract alone significantly reduced the rate of THP-1 cell apoptosis, while it increased the rate of late apoptosis. Molecular investigations showed that treatment with P. crispa extract significantly upregulated the expression of ERK1, p-MAPK, P-P38, and Bcl2, while it significantly reduced the expression of ERK5, Bax, NF-κB, P-NF-κB, CCL1, CCL2, CCL5, CCL22, CXCL1, and CXCL10. Conclusion. Pulicaria crispa extract exhibited anti-inflammatory, antiproliferative, antimigratory, and antiphagocytic effects in LPS-stimulated THP-1 cells. Future studies should investigate these mechanisms in animal models with chronic inflammatory diseases

Avicennia marina endophytic fungi shows antagonism against tomato pathogenic fungi

Mangrove endophytes have been widely studied for several years and Avicennia marina endophytic fungi is known for its remarkable activity against many plant pathogens. Tomato is an important food crop in Saudi Arabia but it is susceptible to fungal diseases.The control of these phytopathogens through fungicides and pesticides is temporary. Thus, this study is aimed to isolate mangrove plant i.e. Avicennia marina endophytic fungal antagonists, characterize their phylogenetic positions and determine their antagonistic activities against tomato fungal pathogens. This study isintended to find a suitable alternative method to control or limit the spread of tomato diseases by using endogenous fungi of mangroves. Ninety fungal pathogens were isolated from three tomato farms in different regions of Riyadh city, Saudi Arabia. In addition, 40 endophytic mangrove i.e. Avicennia marina fungi were isolated from the eastern and western mangrove stands of the Kingdom of Saudi Arabia using potato dextrose agar, Czapek dox broth and malt extract broth media. These fungal strains were phylogenetically classified into at least sixteen genera based on 18S rRNA gene sequencing analysis. The antagonistic strains were screened via a Dual Culture Plate Assay and filter paper disc method. This study showed that endophytic fungal isolates have an antagonistic effect on most tomato pathogenic fungi. Cladosporium sphaerospermum had the highest inhibition while Trichoderma asperellum showed least antagonism against Avicennia marina endophytic fungi. This study proved that endophytic fungi present in Avicennia marina can control many tomato pathogens and their respective diseases. This work also cleared many aspects regarding the use of Avicennia marina endophytic fungal strains as potential biocontrol agents. Also, the diversity observed by these endophytic fungal strains from different areas of Saudi Arabia opened many doors for future research in the control of fungal pathogens

RETRACTED: Forensic applications and genetic characterization of Liaoning Han population revealed by extended set of autosomal STRs

ABSTRACT Background Microsatellites or short tandem repeats (STRs) are considered the gold standard for forensic investigations and autosomal STRs are used for routine forensic personal identification. Aim To provide a precise population database on an extended set of STRs which has never been done before and explore the forensic characteristics of 20 autosomal STRs. Subjects and methods In the current study, we explored the genetic characteristics of 20 STRs loci in 1138 unrelated Han individuals using Goldeneye® 20A multiplex amplification system kit in the Liaoning Han population. Additionally, phylogenetic analysis based on the Nei's standard genetic distance was performed between the Han population and other relevant populations. Results A total of 253 alleles were observed while allelic frequencies ranged from 0.00043 to 0.5369. The combined discrimination power was 99.99999999999999999999789% and the combined exclusion power was 99.999998231%. Most of the loci were in HWE while only five pairs were out of LE. Population genetic analysis showed that the Han population has similarities with other East Asian populations. Conclusion GoldenEyeTM 20A kit detects high diversity in the Liaoning Han population. These STRs which are part of this kit can be used for forensic investigations. Population genetic analysis showed that the Han population is different from the minority populations of Xinjiang

Efficacy of Mushroom Metabolites (Pleurotus ostreatus) as A Natural Product for the Suppression of Broomrape Growth (Orobanche crenata Forsk) in Faba Bean Plants

Broomrape parasitism on faba bean (Vicia faba L.) is the most destructive factor for this crop in Egypt. Pot experiments were conducted during the two successive seasons 2017/2018 and 2018/2019 to study the mitigation of broomrape stress on faba bean using a ten-fold dilution of 10% (w/v) spent mushroom substrate extract (SMSE) of Pleurotus ostreatus and the same dilution of culture filtrate of mushroom (MCF) grown in potato dextrose broth (PDB) at a rate of 48 l hectare&minus;1 compared with the commercial herbicide Roundup (Glyphosate 48% emulsifiable concentrate) at a rate of 144 cm3 ha&minus;1 on the two varieties (Misr3 and Sakha3) cultivated in broomrape-infested soil. The treatments include the use of mushroom products as foliar spray and/or soil amendment in addition to Roundup spraying as a recommended treatment. Using Gas Chromatography-Mass Spectrometry (GC-MS) spectroscopy, our results indicate that the major components of the two mushroom products were bioactive compounds such as polyphenol and high molecular weight aliphatic and aromatic hydrocarbons that may interfere with parasite and host metabolism. These results indicated that SMSE of P. ostreatus and MCF of the same mushroom grown in potato dextrose broth (PDB) gave the best control of broomrape, and increased plant height, root length, leaf area, chlorophyll concentration, relative water content and seed yield (g plant&minus;1), as well as anatomical characters of leaves in the two faba bean varieties (Misr3 and Sakha3), such as upper and lower epidermis, palisade tissue, spongy tissue and vascular bundles. Additionally, electrolyte leakage was decreased in the treated plants compared to control plants and the plants treated with Roundup (glyphosate) because of the important role of SMSE and MCF in the improvement of faba bean water status

Evaluation of Silicon and Proline Application on the Oxidative Machinery in Drought-Stressed Sugar Beet

Drought stress deleteriously affects growth, development and productivity in plants. So, we examined the silicon effect (2 mmol) and proline (10 mmol) individually or the combination (Si + proline) in alleviating the harmful effect of drought on total phenolic compounds, reactive oxygen species (ROS), chlorophyll concentration and antioxidant enzymes as well as yield parameters of drought-stressed sugar beet plants during 2018/2019 and 2019/2020 seasons. Our findings indicated that the root diameter and length (cm), root and shoot fresh weights (g plant−1) as well as root and sugar yield significantly decreased in sugar beet plants under drought. Relative water content (RWC), nitrogen (N), phosphorus (P) and potassium (K) contents and chlorophyll (Chl) concentration considerably reduced in stressed sugar beet plants that compared with control in both seasons. Nonetheless, lipid peroxidation (MDA), electrolyte leakage (EL), hydrogen peroxide (H2O2) and superoxide (O2●−) considerably elevated as signals of drought. Drought-stressed sugar beet plants showed an increase in proline accumulation, total phenolic compounds and up-regulation of antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) activity to mitigate drought effects. Si and proline individually or the combination Si + proline considerably increased root and sugar yield, sucrose%, Chl concentration and RWC, MDA and EL were remarkably reduced. The treatments led to adjust proline and total phenolic compounds as well as CAT and SOD activity in stressed sugar beet plants. We concluded that application of Si + proline under drought stress led to improve the resistance of sugar beet by regulating of proline, antioxidant enzymes, phenolic compounds and improving RWC, Chl concentration and Nitrogen, Phosphorus and Potassium (NPK) contents as well as yield parameters