Identification and characterization of a <Emphasis Type="Italic">Streptomyces</Emphasis> sp. isolate exhibiting activity against multidrug-resistant coagulase-negative Staphylococci

The resistance of 220 coagulase-negative Staphylococci (CNS) (associated with animal disease) to 13 antibiotics were determined using the disk diffusion method. 35.9% of multidrug-resistant coagulase-negative Staphylococci (MR-CNS) exhibited resistance to five or more than five antibiotics; all of these bacteria were resistant to methicillin too. The new Streptomyces sp. ABRIINW111 was isolated from the Zagros Mountains Hamadan, Iran. The 16S rDNA sequence of the isolate indicated that it has 98% similarity to S. levis, but some mutations in the alpha and gamma regions of the 16S rDNA sequence emphasize the probability of the existence of a new species. Preliminary and secondary antibacterial screenings revealed that the isolate is active against gram negative and positive bacteria. The diethyl ether extracted metabolite of the Streptomyces sp. ABRIINW111 showed an effective antibacterial activity against MR-CNS. So the diethyl ether extract of the new Streptomyces sp. strain ABRIINW111 can inhibit the MR-CNS in vitro, and it can offer a new approach to treat MR-CNS infectious patients.     

Responses of Lentil to Co-Inoculation with Phosphate-Solubilizing Rhizobial Strains and Arbuscular Mycorrhizal Fungi

The purpose of this study was to evaluate the responses of lentil (Lens culinariscv. ‘Ziba’) to co-inoculation with arbuscular mycorrhizal (AM) fungi and some indigenous rhizobial strains varying in phosphorus (P)-solubilizing ability in a calcareous soil with high pH and low amounts of available P and nitrogen (N). A factorial experiment with completely randomized block design was conducted under controlled greenhouse conditions. The treatments consisted of (1) three inoculants of Rhizobium leguminosarum bv. viciae strains and a mixed rhizobial inoculant with an effective P-solubilizer strain of Mesorhizobium ciceri, (2) two AM fungal species, Glomus mosseae and Glomus intraradices, (3) two P sources, superphosphate and phosphate rock. Four replications were prepared for each treatment and a related control. After the growth period of three months, the dry matter of shoots plus seeds, their P and N contents, and percent of root colonized by AM fungus were measured. The results showed that the effects of AM fungi, rhizobial strains, and P fertilizers were highly significant (p < 0.01) for all the characteristics studied. The rhizobial strain with P-solubilizing ability showed a more beneficial effect on plant growth and nutrient uptake than the strain without this ability, although both strains had similar effectiveness for N₂-fixation in symbiosis with lentil. Synergistic relationships were observed between AM fungi and some rhizobial strains that related to the compatible pairing of these two microsymbionts. The P-uptake efficiency was increased when P fertilizers were applied along with AM fungi and/or P-solubilizer rhizobial strains.     

Flowering and fruiting phenology,and physico-chemical characteristics of 2-year-old plants of six species of Opuntia from eight regions of Morocco

SUMMARY

We have described the flowering and fruiting phenology of 14 accessions of six Opuntia species grown in Morocco: O. ficus-indica, O. robusta, O. aequatorialis, O. dillenii, O. leucotricha, and O. stricta. We also determined the physicochemical characteristics of their cladodes. For each accession, we used four-to-20 plants. Two systems were used to measure phenology: the extended Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie (BBCH)-scale and the National Phenology Monitoring System. Five principal stages were described: the development of vegetatively-propagated organs (vegetative buds), the development of flower buds, flowering, fruit development, and fruit maturity. The number of vegetative buds varied significantly among the 14 accessions, while only four accessions produced flower buds. After reaching their final size, fruit lengths varied from 3.40–6.40 cm, while fruit diameters varied from 1.93–3.90 cm. The average cladode number differed significantly among genotypes and varied from 1.75–7.75. There were also significant differences in cladode length (13.75–30.63 cm), width (6.25–17.33 cm), thickness (0.65–1.38 cm), fresh weight (FW; 67.50–766.00 g), and dry weight (DW; 8.75–67.15 g) between species. Water content and ash content, as well as total protein and total sugar concentrations, showed significant differences and were within the ranges of 86.67–92.04% (w/w), 12.97–22.08g 100 g^?1 DW, 4.64–11.56g 100 g^?1 DW, and 3.22–12.51 g 100 g^?1 DW, respectively. Our results will help in the development of agronomic management practices and improve the characterisation, valorisation, and use of cactus pear species grown in Morocco.     

Enhancement of the transfection efficiency of DNA into Crocus sativus L. cells via PEI nanoparticles

Over the past decade, several natural and synthetic cationic polymers have been utilized for gene delivery into cells. Among them, polyethylenimine (PEI) was used for gene therapy successfully. The present study investigated the effect of PEI and ultrasound waves on ssDNA delivery into saffron cells. Gel retardation, dynamic light scattering (DLS) and scanning electron microscopy (SEM) assays were employed to determine the physicochemical properties of PEI/f-DNA polyplex (complex of PEI and fluorescently labeled DNA). Moreover, the cytotoxicity of PEI, PEI/f-DNA polyplex and ultrasound were investigated on saffron cells at different concentrations. The gel retardation results indicated that the formation and neutralization of the PEI/f-DNA polyplex were completed at N/P=5. The particle size distribution of the polyplexes was from 50 to 122 nm. The experimental results revealed that the cytotoxicity of the PEI/f-DNA polyplex was lower than that of PEI alone, hence the cells showed both dose- and exposure duration-dependent responses. Furthermore, the viability of saffron cells declined extremely after 5 and 10 min sonication but this reduction was not significant at 2 min exposure duration. The results also indicated that the combined utilization of ultrasound and PEI nanoparticles increased the transfection efficiency of saffron cells up to two times higher than those obtained by PEI or ultrasound separately.     

Effects of arbuscular mycorrhizal fungi on the growth of two turfgrasses grown under greenhouse conditions

ABSTRACT

The need for salinity resistance in turfgrass is increasing because of the enhanced use of effluent and other low-quality water for turfgrass irrigation. Although most turfgrasses form an arbuscular mycorrhizal fungus (AMF) symbiosis, there is little information on the mycorrhization of turfgrass species. Therefore, the aim of this study was to determine the effects of three AMF species, Glomus intraradices Schenck & Smith, Glomus etunicatum Becker & Gerdemann, and Glomus deserticola Trappe & John, and a mixture thereof on the growth, productivity, and nutrient uptake of two species of cool-season turfgrasses, Challenger Kentucky bluegrass (Poa pratensis L.) and Arid tall fescue (Festuca arundinacea Schreb.), and to relate the effects to colonization of the roots by mycorrhiza to assess the dependency of the plants (mycorrhizal dependency [MD]). Following the experimental period (4 months) and measurements, the mycorrhizal inoculated plants had significantly greater biomass production compared to that of non-inoculated plants. MD and shoot mineral contents (particularly P) differed among turfgrass hosting AMF, and the highest value (13%) occurred for P. pratensis and F. arundinacea seedlings colonized with G. intraradices and G. deserticola, respectively. The P content was highest for the F. arundinacea/mixed AMF combination compared to other treatments. We confirmed that mycorrhizal inoculation (P. pratensis/G. intraradices and F. arundinacea/mixed AMF combinations) enhanced plant productivity and nutrient uptake (especially P) even under non-optimum conditions.     

Possibility of using three invasive non-forest tree species as an alternative source for energy production

Non-woody biomass species have high-energy potentials, which could be used for bioenergy production. Invasive species are species spreading into areas, where they are not native, consequently causing environmental and economic problems. Therefore, the present study evaluated the proximate, ultimate, chemical, and fuel characteristics of wood and charcoal of three invasive non-forest tree species in Saudi Arabia: Calotropis procera, Rhazya stricta, and Phragmites australis, which were compared with the wood of Acacia tortilis, a preferable local fuelwood. All these data were discussed to investigate the possibility of using the invasive plants for energy production. The thermal behavior of wood was analyzed using thermo-gravimetric and derivative thermo-gravimetric methods. Overall, compared with the wood of A. tortilis, the woods of R. stricta and P. australis are suitable for energy production. The charcoal produced from P. australis emitted less nitrogen (N) oxide than that of R. stricta.     

Evaluation of the entomopathogenic nematode Steinernema feltiae as a biological control agent of the whitefly,Bemisia tabaci

We evaluated the potential for using infective juveniles of the entomopathogenic nematode Steinernema feltiae to control the sweetpotato whitefly Bemisia tabaci B biotype on cucumber, hibiscus, and collard, under greenhouse conditions. The effects of four adjuvants (PVA, glycerol, Triton X-100, and horticultural spraying oil) on the efficiency of Steinernema feltiae in B. tabaci control were also assessed because they might increase nematode survival by reducing desiccation. The mortality of B. tabaci nymphs increased by 18, 18, and 20% on collard, hibiscus, and cucumber plants when S. feltiae concentration increased from 5000 to 15,000 infective juveniles/mL. When treated with S. feltiae (10000 infective juveniles/mL), second instar nymphs suffered greater mortality than the other instars of B. tabaci, regardless of host plant species. Mortality of B. tabaci nymphs was higher on hibiscus than on collard and cucumber plants. The use of adjuvants greatly increased infection of B. tabaci by S. feltiae. The combination of S. feltiae (10,000 infective juveniles/mL) and 1% horticultural spraying oil increased the mortality of second instar B. tabaci nymphs to 86% on collard and 90% on hibiscus, while the combination of S. feltiae and 0.1% Triton X-100 caused 83% mortality on collard and 89% on hibiscus. The potential for incorporating S. feltiae and the adjuvants in B. tabaci management is discussed.     

The Effect of Human Platelet-Rich Plasma on Adipose-Derived Stem Cell Proliferation and Osteogenic Differentiation

Background: The cultured mesenchymal stem cells (MSC) have been used in many clinical trials; however, there are still some concerns about the cultural conditions. One concern is related to the use of FBS as a widely used xenogeneic supplement in the culture system. Human platelet-rich plasma (hPRP) is a candidate replacement for FBS. In this study, the effect of hPRP on MSC proliferation and osteogenic differentiation has been evaluated. Methods: Human adipose-derived stem cells (hADSC) were expanded. Cells from the third passage were characterized by flow cytometric analysis and used for in vitro experiments. Resazurin and alizarin red stains were used for cell proliferation and osteogenic differentiation assays, respectively. Results: Treatment with hPRP resulted in a statistically significant increase in cell proliferation compare to the negative control group (P<0.001). Cell proliferation in the 15% hPRP group was also significantly higher than that in the 10% hPRP group (P<0.05). Additionally, it caused less osteogenic differentiation of the hADSC compared to the FBS (P<0.001), but in comparison to negative control, it caused acceptable mineralization (P<0.001). Conclusion: These findings indicate that hPRP not only improves the proliferation but also it can be a suitable substitution in osteogenic differentiation for clinical purposes. However, the clinical application value of hPRP still needs more investigation. Key Words: Platelet-Rich Plasma, Adipose tissue, Stem Cells, Cell differentiation, Cell proliferation     

Preparation of zero-valent Co/N-CNFs as an immobilized thin film onto graphite disc for methanol electrooxidation

In this study, we developed new method to prepare one-pot current collector/electrode plate to be utilized in the fuel cell technology. In situ preparation of zero-valent N-doped Co carbon nanofibers (Co/N-CNFs) as an immobilized thin film onto graphite disc was achieved by electrospinning technique, followed by calcination at 1100 oC in argon atmosphere. This catalyst was used for methanol electrooxidation in alkaline media. The effects of nitrogen doping and immobilization on the activity and stability of the prepared catalysts were studied using cyclic voltammetry and chronoamperometry, respectively. SEM, TEM, EDX, XRD, and TGA were used to characterize the morphology and composition of Co/N-CNFs catalysts. The results showed that the electrocatalytic activity as well as the stability of Co/N-CNFs towards methanol electrooxidation in alkaline media were significantly affected by both nitrogen doping and immobilization of the catalyst on the graphite disc. Moreover, the methanol concentration has also affected the electrocatalytic activity of Co/N-CNFs-supported immobilized onto graphite disc and Co/N-CNFs-unsupported graphite disc.