Fuad Ameen

Biodegradation of diesel fuel hydrocarbons by mangrove fungi from Red Sea Coast of Saudi Arabia.

Mangrove sediments were collected from major mangrove stands on the Red Sea Coast of Saudi Arabia. Forty five isolates belonging to 12 genera were purified and five isolates as well as their consortium were found to be able to grow in association with petroleum oil as sole carbon source under in vitro conditions. The isolated strains were identified based on internal transcribed spacer (ITS) rDNA sequence analysis. The fungal strains with the greatest potentiality to degrade diesel oil, without developing antagonistic activity, were identified as Alternaria alternata, Aspergillus terreus, Cladosporium sphaerospermum, Eupenicillium hirayamae and Paecilomyces variotii. As compared to the controls, these fungi accumulated significantly higher biomass, produced extracellular enzymes and liberated larger volumes of CO2. These observations with GC–MS data confirm that these isolates displayed rapid diesel oil bioremoval and when used together as a consortium, there was no antagonistic activity.

Anti-acne, anti-dandruff and anti-breast cancer efficacy of green synthesised silver nanoparticles using Coriandrum sativum leaf extract.

In this present investigation, AgNPs were green synthesised using Coriandrum sativum leaf extract. The physicochemical properties of AgNPs were characterised using UV-visible spectrophotometer, field emission scanning microscopy/energy dispersive X-ray (FESEM/EDX), Fourier transformed infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) analysis. Further, in vitro anti-acne, anti-dandruff and anti-breast cancer efficacy of green synthesised AgNPs were assessed against Propionibacterium acnes MTCC 1951, Malassezia furfur MTCC 1374 and human breast adenocarcinoma (MCF-7) cell line, respectively. The flavonoids present in the plant extract were responsible for the AgNPs synthesis. The green synthesised nanoparticles size was found to be ≈37nm. The BET analysis result shows that the surface area of the synthesised AgNPs was found to be 33.72m(2)g(-1). The minimal inhibitory concentration (MIC) of AgNPs for acne causative agent P. acnes and dandruff causative agent M. furfur was found to be at 3.1 and 25μgmL(-1), respectively. The half maximal inhibitory concentration (IC50) value of the AgNPs for MCF-7 cells was calculated as 30.5μgmL(-1) and complete inhibition was observed at a concentration of 100μgmL(-1). Finally, our results proved that green synthesised AgNPs using C. sativum have great potential in biomedical applications such as anti-acne, anti-dandruff and anti-breast cancer treatment.

Green synthesis of anisotropic zinc oxide nanoparticles with antibacterial and cytofriendly properties

Zinc oxide nanoparticles (ZnONPs) exhibit abundant biomedical applications. Anisotropic ZnONPs with a defined shape and size were synthesized using Bacillus megaterium (NCIM 2326) cell free extract as a bio-reductant. The study investigated the multidimensional effect of ZnONPs on Helicobacter pylori strains and assessed its biosafety in normal human mesenchymal stem cells (hMSc). The highly stable ZnONPs were produced using B. megaterium and Zinc nitrate as a precursor. The phase of ZnONPs formation and structural characterization were performed by UV- visible (UV-Vis), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and Field Emission Scanning electron microscopy (FESEM) analysis. Furthermore, the ZnONPs exhibited higher biocompatibility against human mesenchymal stem cells (hMSC) and proved to be potentially safe in mammalian cells. Corroborating the current investigation, we described the anti-H. Pylori dosage of ZnONPs was safe to hMSC and could efficiently use as nano-antibiotic.

Molecular Characterization and Analysis of Antimicrobial Activity of Endophytic Fungi From Medicinal Plants in Saudi Arabia

Background: Endophytic fungi, which have been reported in numerous plant species, are important components of the forest community and contribute significantly to the diversity of natural ecosystems. Objectives: The current study aimed to evaluate and characterize, at the molecular level, the diversity and antimicrobial activities of endophytic fungi from medicinal plants in Saudi Arabia. Materials and Methods: Fungi growing on plant segments were isolated and identified based on morphological and molecular characteristics. The isolates were grouped into 35 distinct operational taxonomic units, based on the sequence of the internal transcribed spacer regions in the rRNA gene. The colonization frequency and the dominant fungi percentage of these endophytic fungi were calculated. A dual culture technique was adopted to investigate the antifungal activity of these endophytes. Results: Tamarix nilotica showed the highest endophytic diversity with a relative frequency of 27.27%, followed by Cressa cretica with a relative frequency of 19.27%. The most frequently isolated species was Penicillium chrysogenum with an overall colonization rate of 98.57%. Seven out of 35 endophytic fungi exhibited strong antifungal activity to all plant fungal pathogens tested. P. chrysogenum, Fusarium oxysporum, and F. nygamai exhibited the highest inhibition against the human pathogenic bacteria Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Aspergillus sydowii, P. chrysogenum, and Eupenicillium crustaceum showed strong antimicrobial activity against Enterococcus faecalis. Conclusions: The antimicrobial activity of these endophytic microorganisms could be exploited in biotechnology, medicine, and agriculture.

Heavy metal pollution in immobile and mobile components of lentic ecosystems—a review

With growing population and urbanization, there is an increasing exploitation of natural resources, and this often results to environmental pollution. In this review, the levels of heavy metal in lentic compartments (water, sediment, fishes, and aquatic plants) over the past two decades (1997–2017) have been summarized to evaluate the current pollution status of this ecosystem. In all the compartments, the heavy metals dominated are zinc followed by iron. The major reason could be area mineralogy and lithogenic sources. Enormous quantity of metals like iron in estuarine sediment is a very natural incident due to the permanently reducing condition of organic substances. Contamination of cadmium, lead, and chromium was closely associated with anthropogenic origin. In addition, surrounding land use and atmospheric deposition could have been responsible for substantial pollution. The accumulation of heavy metals in fishes and aquatic plants is the result of time-dependent deposition in lentic ecosystems. Moreover, various potential risk assessment methods for heavy metals were discussed. This review concludes that natural phenomena dominate the accumulation of essential heavy metals in lentic ecosystems compared to anthropogenic sources. Amongst other recent reviews on heavy metals from other parts of the world, the present review is executed in such a way that it explains the presence of heavy metals not only in water environment, but also in the whole of the lentic system comprising sediment, fishes, and aquatic plants.

Histopathological studies of experimental Aeromonas hydrophila infection in blue tilapia, Oreochromis aureus

Blue tilapia, Oreochromis aureus, was experimentally infected with Aeromonas hydrophila, a bacterium that damages the gills, liver, and intestine, resulting in histopathological changes in the infected organs. Our histopathological study showed an aggregation of hemocytes with cell necrosis in gills; a massive aggregation of hemocytes and pyknotic nuclei in the hepatopancreas; and a lower rate of hemocyte aggregation in the digestive system of the infected fish.

Aerobic degradation of fenvalerate by a Gram-positive bacterium, Bacillus flexus strain XJU-4

Synthetic pyrethroid—fenvalerate—is one of the most widespread toxic pollutants and has adverse effect on living systems. However, little is known about its biotransformation mechanism in different microorganisms. To elucidate the pathway that might be involved in the catabolism of fenvalerate, we used Bacillus flexus strain XJU-4 (3-nitrobenzoate degrading organism) as an ideal fenvalerate degrading bacterium. Thin layer chromatography, high performance liquid chromatography and gas chromatography–mass spectrometry analysis results revealed that 3-phenoxybenzoate, protocatechuate, and catechol are the three main by-products of fenvalerate metabolism. Additionally, the bacterial cell-free enzymes showed the activities of fenvalerate hydrolyzing esterase, 3-phenoxybenzaldehyde dehydrogenase, 3-phenoxybenzoate dioxygenase, phenol hydroxylase, protocatechuate 2,3-dioxygenase and catechol-2,3-dioxygenase. Thus, in strain XJU-4, protocatechuate and catechol were further metabolized through meta-cleavage pathway. Moreover, laboratory-scale soil experiments results suggest that B. flexus strain XJU-4 is a suitable contender for bioremediation of pyrethroid fenvalerate-contaminated sites.

Biodegradation of Low Density Polyethylene (Ldpe) by Mangrove Fungi from the Red Sea Coast

Forty five fungal isolates belonging to 13 genera were derived from tidal water, floating debris, and sediment collected from mangrove stands on the Red Sea coast of Saudi Arabia. Six of these isolates and their consortium were found to be able to grow in association with low density polyethylene (LDPE) film under in vitro conditions in the absence of dextrose or any other carbon source. These isolates were further tested for their potential to degrade LDPE by co-cultivation under aeration on a rotary shaker. Examination under light and scanning electron microscope revealed that the fungi attached themselves to the surface of the film and grew profusely. As compared to the controls, these fungi accumulated significantly higher biomass, produced more ligninolytic enzymes, and released larger volumes of CO2 during co-cultivation with LDPE. These observations indicated that the selected isolates were able to breakdown and consume the LDPE film.

Potential use of green algae as a biosorbent for hexavalent chromium removal from aqueous solutions

The hexavalent chromium Cr(VI) poses a threat as a hazardous metal and its removal from aquatic environments through biosorption has gained attention as a viable technology of bioremediation. We evaluated the potential use of three green algae (Cladophora glomerata, Enteromorpha intestinalis and Microspora amoena) dry biomass as a biosorbent to remove Cr(VI) from aqueous solutions. The adsorption capacity of the biomass was determined using batch experiments. The adsorption capacity appeared to depend on the pH. The optimum pH with the acid-treated biomass for Cr(VI) biosorption was found to be 2.0 at a constant temperature, 45 °C. Among the three genera studied, C. glomerata recorded a maximum of 66.6% removal from the batch process using 1.0 g dried algal cells/100 ml aqueous solution containing an initial concentration of 20 mg/L chromium at 45 °C and pH 2.0 for 60 min of contact time. Langmuir and Freundlich isotherm equations fitted to the equilibrium data, Freundlich was the better model. Our study showed that C. glomerata dry biomass is a suitable candidate to remove Cr(VI) from aqueous solutions.

A general microwave synthesis of metal (Ni, Cu, Zn) selenide nanoparticles and their competitive interaction with human serum albumin

A series of selenide nanoparticles (3 ± 1 nm sized platelet-like NiSe nanoparticles, uniform CuSe nanorods with a width of ∼12 nm and a length of 65 nm, and distorted ZnSe nano-hexagons with a side length of 12 ± 3.5 nm) were synthesized using a simple microwave irradiation technique using sodium selenite, hydrazine hydrate and starch as a selenide precursor, a reducing agent and a stabilizing agent, respectively. The morphologies and sizes of the as-synthesized nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and energy-dispersive X-ray spectroscopy (EDS) analysis. The interaction between this series of selenide nanoparticles (SNPs) and HSA was investigated using fluorescence and circular dichroism (CD) spectroscopy. The influencing factors such as the quenching type, binding stoichiometries, binding constants, and the free energy change determined using the fluorescence technique showed that SNPs spontaneously bound to HSA in a 1 : 1 ratio through non-fluorescent ground-state complex formation (static quenching mechanism). The binding constant values indicated that the binding forces were in descending order of NiSe > CuSe > ZnSe. The shift in the synchronous fluorescence spectra signified the involvement of the tryptophan moiety in the binding of SNPs with HSA. Based on the Forster theory of energy transfer, the distance between the donor (Trp residues) and the acceptor (SNPs) was obtained. Analysis of the far-UV and near-UV CD spectra of HSA suggested the effect of the SNPs on the secondary and tertiary structures of HSA. These investigations helped us to understand the interaction mechanisms between the nanoparticles and the protein molecule that interprets the pharmacokinetics of these nanoparticles while administering them as drugs.