Anti-dermatophyte effects of lipid nanofibers produced by Yarrowia lipolytica on oily media
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Helia Ramezani,1 Mohaddeseh Larypoor,2,*
1. , Faculty of Biological Science, Department of Biotechnology, Islamic Azad University, North Tehran Branch, Tehran, Iran
2. , Faculty of Biological Science, Department of Biotechnology, Islamic Azad University, North Tehran Branch, Tehran, Iran
- Introduction: Yarrowia lipolytica is an oleaginous yeast that grows on a variety of hydrophobic substrates and able to accumulate lipids intracellularly to ≥40% of its cell dry. Yarrowia lipolytica is recognized as safe by the Food and Drug Administration and is considered for multiple industrial applications. This yeast is separated from natural samples such as dairy products and meat. Due to the process of pleomorphism, it is highly compatible with various types of oily substrates and produces fatty acids, which are both economically viable and have anti-dermatophyte effects. Dermatophytosis is an infection which able to invade and degrade the skin, nails and hair, caused by kreatinophilic fungi called dermatophyte. Clinical symptoms include itching, scaly, inflammation, redness, and deformity of the skin. Dermatophytosis is a predominance in about 20%–25% of all total world populations. Dermatophytosis does not respond well to existing drugs and in most cases recurrence of the infection occurs. Due to the low number of antifungal drugs, side effects, recurrence and prolongation of treatment time, the use of natural products such as electrospun nanofibers with fatty acids have strong anti-dermatophyte effects due to the surface to volume ratio.
- Methods: Yarrowia lipolytica(ATCC 18942) was cultured in different media and examined for pleomorphism under microscope. After culturing yeast in media containing oily pulp such as olive, sunflower and sesame, fatty acid production was examined by GC mass and FTIR. Based on the results, olive pulp was selected for the next steps. Nanofibers containing polyethylene oxide and fatty acids were spun by electrospinning. SEM and FTIR were performed to determine the morphology of nanofibers. Finally, the effect of nanofiber treatments by broth micro-dilution, pour plate and well diffusion methods was determined on the growth of Microsporum canis, Trichophyton rubrum and Trichophyton mentagrophytes.
- Results: After GC mass and FTIR, the fatty acids extracted from olive oil pulp included oleic acid, palmitic acid, linoleic acid and stearic acid, which had the best production of fatty acids among the pulp, so biomass was measured. Microbial fat extraction was performed on it and the amount of fat and dry weight were 4.07 and 7.83 g/L and the yield of microbial fat production was 52.79%, respectively. In the next step, electrospinning solutions, including solutions of polyethylene oxide, oleic acid and fatty acid extracted from olive pulp were prepared. The polymer solution with ratio of 70:30 was the optimized polymer solution. Optimization of device parameters in the electrospinning process, voltage 15 kV, distance 15 cm, flow rate 1 ml⁄h were obtained. The results of FTIR analysis confirmed the placement of fatty acids in PEO polymer and the type of bond interaction. SEM images, showed fibers without nodes and smooth surface and desirable appearance characteristics. MICs of oleic acid/PEO nanofibers for Microsporum canis, Trichophyton rubrum and Trichophyton mentagrophytes were obtained 0.19, 0.31 and 0.09 ml/ml, respectively. MICs of fatty acid/PEO nanofibers for Microsporum canis, Trichophyton rubrum and Trichophyton mentagrophytes were obtained 0.021, 0.021 and 0.044 mg/ml. MFCs of oleic acid/PEO nanofibers for Microsporum canis, Trichophyton rubrum and Trichophyton mentagrophytes were obtained 0.38, 0.62 and 0.18 ml/ml. MFCs of fatty acid/PEO nanofibers for Microsporum canis, Trichophyton rubrum and Trichophyton mentagrophytes were obtained 0.042, 0.042 and 0.088 mg/ml.
- Conclusion: Yarrowia lipolytica is a native and available yeast that is capable of producing fatty acids in low-cost, available and unused substrates. The fatty acids produced by this yeast can be used in various fields such as pharmaceutical and food and have strong anti-dermatophyte effects that can be a good alternative to existing anti-dermatophyte drugs. These fatty acids have no side effects and prevent recurrence of the disease and based on the results, having fungicidal effects on dermatophytes. On the other hand, pulp is an unused compound can be used to produce the necessary compounds by native yeasts very cheaply.
- Keywords: Yarrowia lipolytica, Electrospining, Yeast, Lipid, Dermatophyte
