RESUMEN
This paper addresses the issue of combining the usage of waste frying oil (WFO), as a feedstock, and a lipase produced in solid-state fermentation (SSF), as a biocatalyst, for semi-pilot scale production of biodiesel as fatty acid methyl esters (FAME). Two fungal mutants namely; Rhizopus stolonifer 1aNRC11 mutant F (1F) and Aspergillus tamarii NDA03a mutant G (3G) were used as a cocatalyst. The two mutants were cultivated separately by SSF in a tray bioreactor. The dried fermented solid of 1F and 3G mutants were used in a ratio of 3:1, respectively, for WFO transesterification. Optimization of several semi-pilot process stages including SSF and WFO transesterification reaction conditions resulted in 92.3% conversion of WFO to FAME. This FAME yield was obtained after 48 h using 10% cocatalyst (w/w of WFO), 10% water (w/w of WFO) and 3:1 methanol/ WFO molar ratio at 30 °C and 250 rpm. A preliminary economic evaluation of produced biodiesel price (190 $/Ton) is less than half the price of petroleum diesel in Egypt (401$/Ton) and is about 40.3% the price of biodiesel produced using a pure enzyme, which is a promising result. This strategy makes the biodiesel synthesis process greener, economical and sustainable.
Asunto(s)
Aspergillus/metabolismo , Biocombustibles , Proteínas Fúngicas/metabolismo , Lipasa/metabolismo , Aceites de Plantas/metabolismo , Rhizopus/metabolismo , Aspergillus/genética , Aspergillus/crecimiento & desarrollo , Biocombustibles/análisis , Biocombustibles/microbiología , Reactores Biológicos/microbiología , Esterificación , Fermentación , Proteínas Fúngicas/genética , Lipasa/genética , Mutación , Rhizopus/genética , Rhizopus/crecimiento & desarrolloRESUMEN
Characterization of flavonoids and limonoids in the defatted acetone extract of Khaya senegalensis flowers (A. Juss.) contents was performed using ultra performance liquid chromatography (UPLC) coupled with ultraviolet (UV) and electrospray ionization (ESI) mass spectrometry, furthermore, tandem mass spectrometry (MS/MS) was performed to assist in the structural elucidation. The antimicrobial effect was tested against representative gram positive and negative bacteria and candida. Cytotoxicity of extract was evaluated using the mitochondrial- dependent reduction of MTT. The method used enabled identification of five flavonoid glycosides (di and mono- sugar) and twelve limonoids of different types viz: mexicanolides, phragmalins and angolensate were tentatively identified. The extract was effective against tested microorganism revealing potent growth inhibitory effect on Salmonella typhimurium ATCC 25566, Escherichia coli NRRN 3008 , Pseudomonas aeruginosa ATCC 10145 and fungus Candida albicans EMCC105, MIC ≤ 25µg/µl while MIC ≤ 50 µg/µl for Bacillus cereus, staphylococcus aureus ATCC 6538. Extract showed cytotoxicity against MCF7 (Breast carcinoma cell line) compared to doxorubicin, IC50=88.1(µg/mL) but no activity on HCT 116 (Colon carcinoma cell line) and HepG2 (liver cell carcinoma) was observed. Bioactive compounds in K senegalensis flowers acetone extract possesses promising antimicrobial activity with low cytotoxic effect warrants further investigation for their therapeutic and prophylactic roles
Se ha procedido a la caracterización de los flavonoides y limonoides del extracto acetónico de las flores de la especie Khaya senegalensis (A. Juss.) El análisis de sus componentes se realizó mediante cromatografía líquida de ultra resolución (UPLC) con detección ultravioleta (UV) y de espectrometría de masas de ionización por electrospray (ESI), así como espectrometría de masas (MS / MS) para ayudar en la elucidación estructural de los compuestos. Se comprobó el efecto antimicrobiano en bacterias gram positivas y negativas y levaduras como el género Candida. La citotoxicidad del extracto se evaluó mediante la reducción mitocondrial dependiente de MTT. El método de análisis permitió la identificación de cinco glucósidos flavonoides (di y mono-azúcar) y doce limonoides de diferentes tipos:se identificaron tentativamente mexicanolidos, phragmalinas y angolensato. El extracto fue efectivo contra microorganismos (≤ MIC 25µg / l ), revelando potente efecto inhibidor del crecimiento de Salmonella typhimurium (ATCC 25566), Escherichia coli (NRRN 3008), Pseudomonas aeruginosa (ATCC 10145) y el hongo Candida albicans (EMCC105). Igualmente fue eficaz a MIC ≤ 50 mg / l sobre Bacillus cereus, Staphylococcus aureus (ATCC 6538). Igualmente, el extracto mostró citotoxicidad contra línea celular de carcinoma de mama (MCF7) en comparación con la doxorrubicina, (IC50 = 88.1 (µg/ mL), pero no modificó la actividad en una línea celular de carcinoma colon (HCT 116) y en células de carcinoma del hígado (HepG2). Los compuestos bioactivos en extracto acetónico de flores de K. senegalensis poseen una actividad antimicrobiana prometedora con bajos efectos citotóxicos que garantizan la necesidad de una mayor investigación para conocer completamente sus papeles terapéuticos y profilácticos