No abstract

No abstract

Halotolerant bacteria are regarded as effective oil-scavengers in the polluted saltern and seawater. In this regard, a halotolerant Planococcus was isolated from oilcontaminated area of Dezful north springs, Iran, due to its capacity in biosurfactant (BS) production. To facilitate hydrocarbons degradation, in the current study, the efficiency of BS production as function of growth rate of the halotolerant Planococcus was investigated in the vicinity of heavy crude oil by emulsification index (E24). Subsequently, the BS characterization was made by thin-layer chromatography (TLC), gas chromatography (GC) and infrared spectra analysis, and the stability was determined by E24 value measurement over a certain pH (5-9), temperature (20-100°C) and salt concentration (0-10 % w/v) ranges. The BS production was found to be growth-associated. Detection of a unique band on TLC and GC chromatogram showed the extensive refining capacity of the BS purification, using the medium supernatant under acetone alkaline precipitation followed by oil dissolution from the sediment by carbon tetrachloride. Accordingly, it was clarified that the BS ultimately accumulated outside the cells. The glycolipid quality of the BS was further determined by the routine chemical characterization on TLC and by IR spectra analysis. Moreover, there was no protein detected by lowery total protein assay. Finally, the optimal temperature, pH and NaCl concentration to reach highest E24 values (85.7, 77.0, and 79.0 %) were found at respective 40°C, pH = 9 and 0 % w/v. Our results revealed the practically potential of strain Dezful Isolate for BS large-scale production as environmentally friendly oil-eliminating agents.

No abstract

No abstract

: Curcumin is one of the important natural compounds that is extracted from turmeric. This compound and its derivatives have numerous biological properties, including antioxidant, anticancer, anti-inflammatory, antimicrobial and healing effects. Extensive research in various fields has been conducted on turmeric as it is widely used as a food additive. The significant antifungal activity is one of the major effects of curcumin. In this paper, recent studies on the effects of different forms of curcumin drug on the candidiasis were systematically examined and discussed. The data in this study were extracted from the articles and reports published in the Web of Science, Google Scholar, PubMed, and Scopus databases. After the preliminary investigation, relevant reports were selected and classified based on the incorporated formulation and purpose of the study. After a systematic discussion of the data, it was found that the use of medicinal forms based on nanoparticles can increase the absorption and target the controlled release of curcumin with a more effective role compared to other formulations. Consequently, it can be concluded that new methods of modern medicine can be employed to increase the efficacy of natural pharmaceutical compounds used in the past. In this regard, the present study analyzed the effect of curcumin against various Candida infections using the recent data. It was found that applying a combination of drug formulation or the formulation of curcumin and its derivatives can be an effective strategy to overcome the medicine resistance in fungal infections, especially candidiasis.

An antimicrobial glycolipid biosurfactant (GBS), extracted and identified from a marine bacterium, was studied to inhibit pathogenic microorganisms. Production of the GBS was optimized using a statistical method, a response surface method (RSM) with a central composite design (CCD) for obtaining maximum yields on a cost-effective substrate, molasses. The GBS-producing bacterium was identified as Buttiauxella Species in terms of biochemical and molecular characteristics. This compound showed a desirable antimicrobial activity against some pathogens such as E. coli, Bacillus subtilis, Bacillus cereus, Candida albicans, Aspergilus niger, Salmonella enterica. The rheological studies described the stability of the GBS at high values in a range of pH (7-8), temperature (20-60) and salinity (0%-3%). The statistical optimization of GBS fermentation was found to be pH 7, temperature 33 • C, Peptone 1%, NaCl 1% and molasses 1%. The potency of the GBS as an effective antimicrobial agent provides evidence for its use against food and human pathogens. Moreover, favorable production of the GBS in the presence of molasses as a cheap substrate and the feasibility of pilot scale fermentation using an RSM method could expand its uses in food, pharmaceutical products and oil industries.

Development of a green chemistry process for the synthesis of silver nanoparticles (AgNPs) has become a focus of interest. Characteristics of AgNPs were determined using techniques, such as ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared (FTIR) analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD). The synthesised AgNPs using Thymus kotschyanus had the most growth inhibition against gram-positive bacteria such as Staphylococcus aureus and Bacillus subtilise, while the growth inhibition of AgNPs at 1000-500 µg/ml occurred against Klebsiella pneumonia and at 1000-250 µg/ml of AgNPs was observed against E. coli. The UV-vis absorption spectra confirmed the formation of the AgNPs with the characteristic peak at 415 nm and SEM micrograph acknowledged spherical particles in a nanosize range. FTIR measured the possible biomolecules that are responsible for stabilisation of AgNPs. XRD analysis exhibited the crystalline nature of AgNPs and showed face-centred cubic structure. The synthesised AgNPs revealed significant antibacterial activity against gram-positive bacteria.