7 research outputs found
Optimization of Growth Conditions for Purification and Production of L-Asparaginase by Spirulina maxima
L-asparaginase (L-AsnA) is widely distributed among microorganisms and has important applications in medicine and in food technology sectors. Therefore, the ability of the production, purification, and characterization of AsnA from Spirulina maxima (SM) were tested. SM cultures grown in Zarrouk medium containing different N2 (in NaNO3 form) concentrations (1.25, 2.50, and 5.0鈥塯/L) for 18 days contained a significant various quantity of dry biomass yields and AsnA enzyme levels. MS L-AsnA activity was found to be directly proportional to the N2 concentration. The cultures of SM at large scales (300鈥塋 medium, 5鈥塯/L N2) showed a high AsnA enzyme activity (898鈥塈U), total protein (405鈥塵g/g), specific enzyme activity (2.21鈥塈U/mg protein), and enzyme yield (51.28鈥塈U/L) compared with those in low N2 cultures. The partial purification of crude MS AsnA enzyme achieved by 80% ammonium sulfate AS precipitated and CM-Sephadex C-200 gel filtration led to increases in the purification of enzyme with 5.28 and 10.91 times as great as that in SM crude enzymes. Optimum pH and temperature of purified AsnA for the hydrolyzate were 8.5 and 37 卤 0.2掳C, respectively. To the best of our knowledge, this is the first report on L-asparaginase production in S. maxima
Estudio comparativo sobre la deterioraci贸n de aceites por calentamiento en microonda y convencional
Refined cottonseed oil and hydrogenated palm oil were heated by two methods, i.e., conventionally by gas-cooker and microwaves. Quality assurance methods such as refractive index, color, diene content, acid value, peroxide value, TBA value, iodine value, petroleum ether insoluble oxidized fatty acid content and degree of polymerization were determined. Exposing the oil samples to various heating times and microwave oven power caused some hydrolysis to free fatty acids, accelerated the formation of hydroperoxides and secondary oxidation products. The values from each test increased with both the power settings of microware oven and time of heating. In general, the development of rancidity for refined cottonseed oil heated by microwaves was twice faster than that produced by conventional heating. Also, the chemical values for refined cottonseed oil were much higher than that of hydrogenated palm oil in all cases.Se han calentado aceites de semilla de algod贸n y de palma hidrogenado mediante dos m茅todos: convencionalmente en cocina de gas y microonda. Se han determinado como m茅todos de garant铆a de calidad el 铆ndice de refracci贸n, color, contenido en dienos, 铆ndice de acidez, 铆ndice de per贸xido, 铆ndice de TBA, 铆ndice de iodo, contenido en 谩cidos grasos oxidados insolubles en 茅ter de petr贸leo y grado de polimerizaci贸n.
La exposici贸n de las muestras de aceite a varios tiempos de calentamiento y potencia del horno microonda caus贸 hidr贸lisis hacia 谩cidos grasos libres, aceler贸 la formaci贸n de hidroper贸xidos y productos de oxidaci贸n secundarios. Los valores para cada test aumentaron con los ajustes de potencia del horno microonda y el tiempo de calentamiento. En general, el desarrollo de la rancidez para aceite de semilla de algod贸n refinado calentado por microonda fue 2 veces m谩s r谩pido que el producido por calentamiento convencional.
Tambi茅n, los 铆ndices qu铆micos para aceites de semilla de algod贸n refinado fueron mucho mayores que los de aceite de palma hidrogenado en todos los casos
Egyptian Artbrospira phytosterols: Production, identification, antioxidant and antiproliferative activities
Cultivation of microalgae as a source of phytosterol and other lipid compounds has gained more attention for commercial applications in pharmaceutical, cosmetic and food function industries. In this research, native Spirulina maxima SM from Egypt was grown in individual cultures containing various concentrations of nitrogen (N), phosphorus (P) and sulfur (S) elements in order to elucidate the effect of its elements on lipid and phytosterols production and to evaluate its antioxidant and antiproliferative activities. The results revealed that the SM was able to grow in different concentrations of testing elements S (from 0.3 to 2.4 mM), P (from 0.3 to 2.4 mM) and N (0.3 to 3.2 mM) with significant differences. A high potential for production of MS biomass, total lipid and phytosterol contents were obtained in individual cultures containing 0.6 mM N, 0.6 mM P and 0.80 mM, respectively. Therefore, these concentrations (combination of S+P+N element) were selected for cultivation of SM at large scale in a column photobioreactor (PBR 300 L) to induce sufficient SM biomass so that, we can obtain an adequate amount of total lipid and phytosterol contents. Phytosterols (PS) of native SM grown in the 300 L PBR were partially purified from unsaponified extracts of SM total lipid followed by its purification by crystallization process. The identification and quantification of PS profile were performed by GC-FID analysis. The results revealed high levels of campsterol, D7-Avena sterol, 尾-sitosterol, stigmasterol and other compounds. These PS compounds showed marked in vitro superoxide, DPPH and OH radical scavenging activity, which was comparable with the results obtained with standard antioxidants BHA or 伪-tocopherol. Moreover, SM phytosterols exhibited anti-proliferative activity against three human cancer cell lines (MCF-7, Hep-G2 and HCT-116) with IC50 values less than 11.62 fig/mL as assessed by in vitro MTT colorimetric method. Thus, SM phytosterol may be considered as a potential natural source of promising ingredient in the future for a range of health applications for human, cosmetic industries and in functional food
Egyptian Arthrospira phytosterols: production, identification, antioxidant and antiproliferative activities
Cultivation of microalgae as a source of phytosterol and other lipid compounds has gained more attention for commercial applications in pharmaceutical, cosmetic and food function industries. In this research, native Spirulina maxima SM from Egypt was grown in individual cultures containing various concentrations of nitrogen (N), phosphorus (P) and sulfur (S) elements in order to elucidate the effect of its elements on lipid and phytosterols production and to evaluate its antioxidant and antiproliferative activities. The results revealed that the SM was able to grow in different concentrations of testing elements S (from 0.3 to 2.4 mM), P (from 0.3 to 2.4 mM) and N (0.3 to 3.2 mM) with significant differences. A high potential for production of MS biomass, total lipid and phytosterol contents were obtained in individual cultures containing 0.6 mM N, 0.6 mM P and 0.80 mM, respectively. Therefore, these concentrations (combination of S+P+N element) were selected for cultivation of SM at large scale in a column photobioreactor (PBR 300 L) to induce sufficient SM biomass so that, we can obtain an adequate amount of total lipid and phytosterol contents. Phytosterols (PS) of native SM grown in the 300 L PBR were partially purified from unsaponified extracts of SM total lipid followed by its purification by crystallization process. The identification and quantification of PS profile were performed by GC-FID analysis. The results revealed high levels of campsterol, D7-Avena sterol, 尾-sitosterol, stigmasterol and other compounds. These PS compounds showed marked in vitro superoxide, DPPH and .OH radical scavenging activity, which was comparable with the results obtained with standard antioxidants BHA or 伪-tocopherol. Moreover, SM phytosterols exhibited anti-proliferative activity against three human cancer cell lines (MCF-7, Hep-G2 and HCT-116) with IC50 values less than 11.62 碌g/mL as assessed by in vitro MTT colorimetric method. Thus, SM phytosterol may be considered as a potential natural source of promising ingredient in the future for a range of health applications for human, cosmetic industries and in functional food