PHYTOCHMICAL ANALYSIS AND ANTIFUNGAL POTENTIAL OF SORGHUM HELEPENSE L. FOR THE MANAGEMENT OF OCHRATOXIGENIC FUNGI

Ochratoxigenic fungal species are a major cause of various infections in plants and posed a serious threat to their consumers,including humans and animals. In the current study the objective was to examine the in vitro efficacy of different concentrations of leaves methanolic extract of S. helepense L. (Pers.) against target pathogenic ochratoxin producing fungal species (Trichoderma viride Pers., Trichoderma harzianum Rifai. and Cladosporium cladosporioides (Fresen.) G.A. de Vries).For this purpose, different concentrations viz. 2%, 4%, 6%, 8% and 10% of leaf methanolic extract were prepared and tested for antifungal potential in a completely randomized design (CRD). Results revealed that all the applied concentrations of S. helepense inhibited the growth of all the tested fungal strain. Maximum growth inhibition was observed in 2% of concentration of methanolic extract of S. helepense in case of C. cladosporoides i.e. 84%. On the other hand minimum reduction was observed in 4% of concentration of methanolic extract of S. helepense against T. viride as compared to control. The phytochemical analysis was also conducted to evaluate that which chemical entities were present that account for antifungal potency of methanolic extract of S. helepense. Results of phytochemical analysis revealed the occurrence of saponins, alkaloids, coumarins, flavonoids and tannins while the plant is devoid of terpenoids, phlobatanins and glycosides respectively. Hence it can be concluded that the methanolic leaf extract of the tested plant proved to be beneficial for inhibiting the growth of test ochratoxigenic fungi.

The first detection of Botryosphaeria sinensis on white lupine

Fungal strain MF KP-12.1, which is similar in morphological and cultural characteristics to Botryosphaeria fungi, was isolated from the seeds of white lupine variety Dega grown in Oryol region in 2018. Phylogenetic analysis of the large rRNA subunit (LSU), elongation factor-1α (TEF) and internal transcribed spacer (ITS) fragments was used to accurately identify the isolated strain as B. sinensis. When 2-week-old white lupine plants were treated under laboratory conditions with mycelial suspension of B. sinensis MF KP-12.1, plant damage reached 67 % on day 3, and 100 % plant death was observed on day 10. Pathogenicity of B. sinensis MF KP-12.1 was confirmed by re-isolation of the strain from damaged plant tissue. This is the first detection of B. sinensis on white lupine, which has not been previously reported as a host for this fungus. It is also the first detection of B. sinensis in Russia.

The Potency of Fungal-Fabricated Selenium Nanoparticles to Improve the Growth Performance of Helianthus annuus L. and Control of Cutworm Agrotis ipsilon

The application of green nanotechnology in agriculture has been receiving substantial attention, especially in the development of new nano-fertilizers and nano-insecticides. Herein, the metabolites secreted by the fungal strain Penicillium chrysogenum are used as a reducing agent for selenium ions to form selenium nanoparticles (Se-NPs). The synthesized Se-NPs were characterized using color change, UV-Vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), and dynamic light scattering (DLS). The biomass filtrate of the fungal strain changed from colorless to a ruby red color after mixing with sodium selenite with a maximum surface plasmon resonance at 262 nm. Data exhibits the successful formation of spherical, amorphous Se-NPs with sizes ranging between 3–15 nm and a weight percentage of 38.52%. The efficacy of Se-NPs on the growth performance of sunflower (Helianthus annuus L.) and inhibition of cutworm Agrotis ipsilon was investigated. The field experiment revealed the potentiality of Se-NPs to enhance the growth parameters and carotenoid content in sunflower, especially at 20 ppm. The chlorophylls, carbohydrates, proteins, phenolic compounds, and free proline contents were markedly promoted in response to Se-NPs concentrations. The antioxidant enzymes (peroxidase, catalase, superoxide dismutase, and polyphenol oxidase) were significantly decreased compared with the control. Data analysis showed that the highest mortality for the 1st, 2nd, 3rd, 4th, and 5th instar larvae of Agrotis ipsilon was achieved at 25 ppm with percentages of 89.7 ± 0.3, 78.3 ± 0.3, 72.3 ± 0.6, 63.7 ± 0.3, and 68.7 ± 0.3 respectively after 72 h.

Identification and glass biodeterioration of Chaetomium globosum TTHF1-3 isolated from optical instrument at Thai Hoa, Nghe An province

The colonization and growth of harmful fungi on the glass surface have caused irreversible damage to optical quality. Harmful grades observed on the optical instruments depend on the biological characteristics of fungi that vary from species to species. The present study focused on isolation, identification, and evaluation of glass biodeterioration properties such as organic acid and exopolysaccharide production of fungal strain Chaetomium globosum TTHF1-3 isolated from lens of optical instrument collected at Thai Hoa, Nghe An province. Under microscopic observation, the fungal strain TTHF1-3 cells showed brown or dark brown color perithecia and ascospores. Based on ITS sequence analyses, the strain TTHF1-3 was found to share 100% sequence identity with that of C. globosum species deposited on GenBank (NCBI). A in situ biodeterioration test exhibited the hyphal surface coverage of strain TTHF1-3 reaching 29.77±1.15%, which corresponded to harmful grade 2 based on the ISO 9022-11:2015 criteria. When incubated on MT4 medium containing glucose and mineral elements, the pH values of C. globosum TTHF1-3 culture were significantly decreased from 6.5 to 3.12±0.12, which was in contrast to MT1 medium. In addition, fungal strain TTHF1-3 was able to produce 8.2±0.3 g/L exopolysaccharides. The findings in the present study confirmed that C. globosum TTHF1-3 was harmful fungus responsible for glass biodeterioration.

Active Antibiotics Production by Actinomycetes Indigenous To Saudi Arabia Soils

Streptomyces are the most popular among the Actinomycetes groups and found in soils worldwide. They form an important part of the soil ecology within the Actinomycetales order. Streptomyces are diverse as secondary antibiotic metabolites such as Novobiocin, Amphotericin, Vancomycin, Neomycin, Gentamicin, Chloramphenicol, Tetracycline, Erythromycin and Nystatin. Thus, the current study was aimed to isolate, identify and assess the active antibiotic metabolites produced by different actinomyces sp. found in Saudi Arabian soils. Six samples were collected from desert soils of the Al Thumamah area and analyzed using GS-MS. Scanning Electron Microscopy was used to identify the bacterial strains along with their antibiotic metabolites effectiveness of secondary metabolites (antibiotics) against different Gram-positive (Bacillus subtilis, Staphylococcus aureus), negative pathogens (Pseudomonas aeruginosa, Escherichia coli, Salmonella suis, and Shigella sonnei) as well as the fungal strain Candida albicans was investigated. Thirty active bacterial (F1-30) strains were isolated from the soil samples and the strains F3, F7, F22, F30 have white, gray, pink, yellow and red colours respectively. Only ten strains (F13, F14, F15, F16, FI7, F18, F19, F20, F21, and F22) were found to have antimicrobial activity against at least one pathogen. The optimum growth environment was pH 4-10, temperature (300C), and NaCl (7% w/v) concentration. According to our findings, the extreme desert environment of Al Thumamah from Saudi Arabia is rich in its actinobacterial population with diverse colouring groups and various physiological and biochemical properties. This shows it’s capability of generating secondary metabolite elements that could inhibit pathogenic microorganisms.

Biotransformation of Chromium (VI) via a Reductant Activity from the Fungal Strain Purpureocillium lilacinum

Industrial effluents from chromium-based products lead to chromium pollution in the environment. Several technologies have been employed for the removal of chromium (Cr) from the environment, including adsorption, ion-exchange, bioremediation, etc. In this study, we isolated a Cr (VI)-resistant fungus, Purpureocillium lilacinum, from contaminated soil, which could reduce chromium. We also characterized a reductant activity of dichromate found in the cellular fraction of the fungus: optimal pH and temperature, effect of enzymatic inhibitors and enhancers, metal ions, use of electron donors, and initial Cr (VI) and protein concentration. This study also shows possible mechanisms that could be involved in the elimination of this metal. We observed an increase in the reduction of Cr (VI) activity in the presence of NADH followed by that of formate and acetate, as electron donor. This reduction was highly inhibited by EDTA followed by NaN3 and KCN, and this activity showed the highest activity at an optimal pH of 7.0 at 37 °C with a protein concentration of 3.62 µg/mL.