Pilot Scale of Microalgal Production Using Photobioreactor

Microalgal gained much interest as a promising sustainable feedstock for the production of food, feed, bulk chemicals and biofuels. Pilot scale of microalgal is needed to bridge the gap between laboratory scale research and commercial application. Commercial applications of microalgal have been used for a wide array of functions including, pharmaceutical, health sector, nutraceutical, cosmetics and agriculture. Numerous photobioreactors (PBRs) of different volume and shapes have been designed. Cost of PBR has a major influence on production cost for large scale biomass. There are several ways to reduce production cost depends on the type of algal strain, type of PBRs, CO2 and the production technology of the biomass. Dilution rate is an important factor, which affects the biomass productivity, rate and ultimately what needs to be maximized

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 g/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 L medium, 5 g/L N2) showed a high AsnA enzyme activity (898 IU), total protein (405 mg/g), specific enzyme activity (2.21 IU/mg protein), and enzyme yield (51.28 IU/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 ± 0.2°C, respectively. To the best of our knowledge, this is the first report on L-asparaginase production in S. maxima

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, β-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 α-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 µg/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

Enhancement of phenolics, flavonoids and glucosinolates of Broccoli (Brassica olaracea, var. Italica) as antioxidants in response to organic and bio-organic fertilizers

A field experiment was carried out to study the effect of organic and bioorganic fertilizers on growth parameters, yield and the quality of two broccoli cultivars (Calabrese and Southern star). Bio-organic fertilizers gave better results for all vegetative growth parameters for Southern star cultivar compared to Calabrese cultivar. Total phenolic content (TPC), total flavonoid content (TFC) and total glucosinolates content (TGsC) were almost higher in Calabrese cultivar as a result of organic fertilizer treatment. The antioxidant activities of both cultivars were evaluated and Calabrese cultivar showed the higher1, 1-diphenyl-2-picrylhydrazyl DPPH. scavenging activity expressed as IC50 (its concentrations for 50% inhibition) (16.56 μg/ml) compared to Southern star (19.42 μg/ml). In addition, Calabrese cultivar showed the higher chelating power (75.36 μg/ml) than Southern star (72.43 μg/ml) at (30 μg/ml) when the organic fertilizer was applied. The results indicated that there is a good margin for enhancing antioxidant compounds of broccoli for economic production using organic fertilization. This study indicated the potential application of broccoli as a potent natural source of antioxidants as nutraceuticals