RESUMEN
Surfactants are amphipathic compounds containing both hydrophilic and hydrophobic groups, capable to lower the surface or interfacial tension. Considering the advantages of the use of biosurfactants produced by microorganisms, the aim of this paper was to develop and characterize a biosurfactant produced by Streptomyces sp. DPUA1559 isolated from lichens of the Amazon region. The microorganism was cultured in a mineral medium containing 1% residual frying soybean oil as the carbon source. The kinetics of biosurfactant production was accompanied by reducing the surface tension of the culture medium from 60 to values around 27.14 mN/m, and by the emulsification index, which showed the efficiency of the biosurfactant as an emulsifier of hydrophobic compounds. The yield of the isolated biosurfactant was 1.74 g/L, in addition to the excellent capability of reducing the surface tension (25.34 mN/m), as observed from the central composite rotational design when the biosurfactant was produced at pH 8.5 at 28°C. The critical micelle concentration of the biosurfactant was determined as 0.01 g/mL. The biosurfactant showed thermal and pH stability regarding the surface tension reduction, and tolerance under high salt concentrations. The isolated biosurfactant showed no toxicity to the micro-crustacean Artemia salina, and to the seeds of lettuce (Lactuca sativa L.) and cabbage (Brassica oleracea L.). The biochemistry characterization of the biosurfactant showed a single protein band, an acid character and a molecular weight around 14.3 kDa, suggesting its glycoproteic nature. The results are promising for the industrial application of this new biosurfactant.
Asunto(s)
Streptomyces/metabolismo , Tensoactivos/metabolismo , Líquenes/microbiología , Valores de Referencia , Semillas/efectos de los fármacos , Temperatura , Factores de Tiempo , Aceite de Soja/química , Recuento de Colonia Microbiana , Análisis de Varianza , Espectroscopía Infrarroja por Transformada de Fourier , Medios de Cultivo , Electroforesis en Gel de Poliacrilamida , Fermentación , Concentración de Iones de HidrógenoRESUMEN
Surfactants are amphipathic compounds containing both hydrophilic and hydrophobic groups, capable to lower the surface or interfacial tension. Considering the advantages of the use of biosurfactants produced by microorganisms, the aim of this paper was to develop and characterize a biosurfactant produced by Streptomyces sp. DPUA1559 isolated from lichens of the Amazon region. The microorganism was cultured in a mineral medium containing 1% residual frying soybean oil as the carbon source. The kinetics of biosurfactant production was accompanied by reducing the surface tension of the culture medium from 60 to values around 27.14 mN/m, and by the emulsification index, which showed the efficiency of the biosurfactant as an emulsifier of hydrophobic compounds. The yield of the isolated biosurfactant was 1.74 g/L, in addition to the excellent capability of reducing the surface tension (25.34 mN/m), as observed from the central composite rotational design when the biosurfactant was produced at pH 8.5 at 28°C. The critical micelle concentration of the biosurfactant was determined as 0.01 g/mL. The biosurfactant showed thermal and pH stability regarding the surface tension reduction, and tolerance under high salt concentrations. The isolated biosurfactant showed no toxicity to the micro-crustacean Artemia salina, and to the seeds of lettuce (Lactuca sativa L.) and cabbage (Brassica oleracea L.). The biochemistry characterization of the biosurfactant showed a single protein band, an acid character and a molecular weight around 14.3 kDa, suggesting its glycoproteic nature. The results are promising for the industrial application of this new biosurfactant.
Asunto(s)
Líquenes/microbiología , Streptomyces/metabolismo , Tensoactivos/metabolismo , Análisis de Varianza , Recuento de Colonia Microbiana , Medios de Cultivo , Electroforesis en Gel de Poliacrilamida , Fermentación , Concentración de Iones de Hidrógeno , Valores de Referencia , Semillas/efectos de los fármacos , Aceite de Soja/química , Espectroscopía Infrarroja por Transformada de Fourier , Streptomyces/crecimiento & desarrollo , Streptomyces/aislamiento & purificación , Tensión Superficial , Tensoactivos/análisis , Tensoactivos/química , Temperatura , Factores de TiempoRESUMEN
Leishmaniasis is an extremely difficult disease to treat. Previously, it was shown that oral Kalanchoe pinnata (Kp) leaf extract is strongly effective against murine leishmaniasis. Here, it is shown that the serum levels of alanine-aminotransferase (ALT), aspartate-aminotransferase (AST), urea and alkaline phosphatase were unchanged in mice orally treated with supraoptimal Kp doses for 30 days, indicating the absence of chronic toxicity to the liver, heart or kidney. Additionally, evidence is presented that human leishmaniasis may also be controlled with oral Kp. A 36-year-old man with an active cutaneous leishmaniasis was orally treated with 30 g wet weight of Kp leaves/day for 14 days. During the Kp treatment, the lesion stopped growing and slightly decreased. No adverse reactions or toxicity was observed. This study reports for the first time that Kalanchoe pinnata contains substances potentially active and safe for the oral treatment of human cutaneous leishmaniasis.