The Influence of Different Light Wavelengths on Growth, Enzymes Activity and Photosynthesis of the Marine Microalga Dunaliella parva W.Lerche 1937

يعتبر الضوء عاملاً هامًا يؤثر على نمو الطحالب الدقيقة وكفاءة التمثيل الضوئي لها ؛ ومع ذلك ، لا يُعرف الكثير عن كيفية تأثير شدة الضوء مع الطول الموجي على قدرة التمثيل الضوئي ونمو الطحالب البحرية الدقيقة. في هذه الدراسة ، تمت دراسة نمو الطحالب البحرية الخضراء الدقيقة ديوناليلا بارفا  واقلمته تحت شدة الضوء المختلفة (25 ~ 70 μmol m-2 s-1) ونوعية الضوء (الأزرق والأخضر والأحمر) مقارنة بالضوء الأبيض عند 40 μmol m-2 s-1  كتجربة ضابطة (كنترول). تمت مراقبة النمو عن طريق حساب عدد الخلايا ومحتوى الصبغة وتراكيز Chl a و Chl b والكاروتينات. تم تسجيل النمو الأمثل وأعلى كفاءة التمثيل الضوئي (Fv / Fm) بكثافة ضوء 40 μmol m-2 s-1 ، ضوء أبيض ، و 1.25 مولار كلوريد الصوديوم (. 1.47 and 0.678×106 cell mL-1، على التوالي). أظهر نشاط إنزيمات مضادات الأكسدة ، بما في ذلك الكاتلاز والبيروكسيديز وكذلك محتوى الأسكوربات ، أعلى قيم بلغت 0.190 µM/min.mg Chl, 0.434 and 13.3 mg/g f.wt.  على التوالي ، تحت تأثير  الضوء الأخضر ، الذي أكد وجود ضغوط بيئية.Light is an important factor that influences the growth and photosynthetic efficiency of microalgae; however, little is known about how light intensity together with the wavelength affect the photosynthetic capacity and growth of marine microalgae. In the present study, the growth of the marine green microalga Dunaliella parva was studied and optimized under different light intensities (25 ~ 70 μmol m-2 s-1) and qualities (blue, green, and red) in comparison with white light at 40 μmol m-2 s-1 as a control. The growth was monitored by counting the cell number, pigment content, Chl a, Chl b, and carotenoids concentrations. The optimal growth and highest photosynthetic efficiency (Fv/Fm) were recorded at a light intensity of 40 μ mol m-2 s-1, white light, and 1.25 M NaCl (1.47 and 0.678×106 cell mL-1, respectively). The activity of antioxidant enzymes, including catalase and peroxidase, as well as ascorbate content, showed the highest values of 0.190 µM/min.mg Chl, 0.434 and 13.3 mg/g f.wt. respectively, under the green light, which confirmed the presence of environmental stresses

Evaluation of Polycladia myrica mediated selenium nanoparticles (PoSeNPS) cytotoxicity against PC-3 cells and antiviral activity against HAV HM175 (Hepatitis A), HSV-2 (Herpes simplex II), and Adenovirus strain 2

IntroductionThe trace element selenium is an essential micronutrient for the health of humans, animals, and microbesMany researchers have recently become interested in selenium nanoparticles (SeNPs) because of their biocompatibility, bioavailability, and low toxicity. Consequently, selenium nanoparticles are widely used in various biomedical applications and wastewater bioremediation due to their greater bioactivity. Green biosynthesis of nanoparticles is common and preferable nowadays.MethodsIn this work, the selenium nanoparticles were synthesized using the brown seaweed Polycladia myrica aqueous extract and characterized using seven parameters, SEM, TEM, UV spectra, Zeta potential, EDX, X-ray differaction and FTIR, then examined for their cytotoxicity using PC-3 cells and normal mammalian cells from the African green monkey kidney (Vero) were used to test the effectiveness of the produced Polycladia myrica mediated selenium nanoparticles as an anticancer agent and antiviral activity against HAV HM175 (Hepatitis A), HSV-2 (Herpes simplex II), and Adenovirus strain 2.ResultsThe phycosynthesized nanoparticles exhibit antiviral activity (40.25 ± 2.61, 8.64 ± 0.82, and 17.39 ± 1.45%) against HAV-10, Adenovirus, and HSV-2, respectively. The IC50 values of the two cell types human prostate PC-3 and Vero were 123.51 ± 4.07 g/mL and 220.53 ± 6.89 g/ mL, respectively. The maximum inhibitory percent was 86.15 ± 2.31 against PC-3 cells. At the same time, at a concentration of 125 g/mL.DisscusionThis work showed that PoSeNPS have good antiviral activity against HAV-10 virus with an antiviral percent of 40.25%, despite weak antiviral activity against Adenovirus and HSV-2 with antiviral percent (8.64% and 17.39%), respectively. The cytotoxicity effect of these nanoparticles was determined against PC-3 with a maximum inhibitory percent of 80.53%. These nanoparticles have no hazardous effect against normal Vero cells as the viability percent was (78.39% and 49.23%) for Vero cells and PC-3 cells, respectively, at 125 μg/mL

Outdoor Cultivation of Spirulina platensis for Mass Production

In the present study, the blue-green alga Spirulina platensis (NRC) was used for mass production under outdoor cultivation in three open ponds with a final capacity of 75 m3 net cultivation volume. Subculturing was performed within sequences and gradual volumes till 1,200 L open plate photobioreactor. The first and second ponds (30 cm depth) were used for the actual continuous production, while the third pond (80 cm depth) was used as a continuous inoculum supplier. In spite of low turbulence of the third pond due to high depth, all ponds had the same mechanical specification concerning paddle wheel structure and turbulence rate (16 rpm). A final nutrient concentration was employed based on Zarrouk medium by commercial grade compounds with some modifications. The nutrition was performed for the third pond by extra supplementation of extra doses of macro and micro-nutrients during the production period and dilution took place when culture was transferred to production ponds (first and second). Each production pond was harvested every 48 hours and the remainder water was return again into the third pond. The harvested pond yielded about 40 kg per day of fresh algal weight containing about 85% moisture on a dry weight basis. The results proved that using urea as nitrogen and carbon source with corn steam liquor instead of sodium nitrate and low bicarbonate, reduces production cost and supports growth medium by an adequate amount of carbon dioxide on the expense of the luxury use of sodium bicarbonate (16.8 g.l-1). Chemical analysis of the produced biomass showed 58-62% crude protein, 6-8% of ether extract and 8-11% of total carbohydrates. S. platensis contained total essential amino acids (131.3 mg/g), with a predominance of arginine followed by glutamic acid, leucine and phenylalanine

Induction of the synthesis of bioactive compounds of the marine alga Tetraselmis tetrathele (West) Butcher grown under salinity stress

This work aims at the induction of the synthesis bioactive compounds in microalgae which are used in aquacultures. Experiments were done using Tetraselmis tetrathele in batch culture for 8 days under different salinity levels. The growth of the alga at salinity 20 ppm was increased by fivefold and synthesis of carotenoids by 20-fold in comparison to the controlled. Increasing NaCl concentration resulted in increasing the fatty acid accumulation in T. tetrathele cells. Saturated fatty acids were the main constituent in the fatty acid methyl esters (FAMEs) (3.48 mg/g) at salinity 25 ppm. The predominated fatty acids were tridecylic, myristic and pentadecanoic which have potential antimicrobial activities. GC–MS analyses of the alga acetone extract grown under different NaCl concentrations were established. The results showed the presence of 18 bioactive compounds: 9-octadecenamide; in addition to the different esters of some fatty acids: hexanedioic, 1,2-cyclohexanedicarboxylic, phthalic, oleanitrile, hexanedioic and 1,2-cyclohexanedicarboxylic (71.5%; 64.9%; 55.4%; 49.6%; 18.7%; 25.2% and 14.5%, respectively). The study suggested that the alga biosynthesized various bioactive compounds under different salinity levels as defense mechanisms. Accordingly, the growth of T. tetrathele under salinity stress before being used in aquacultures is recommended

In vitro anticancer activity of polysaccharide extracted from red alga Jania rubens against breast and colon cancer cell lines

Objective: To evaluate the potential role of the polysaccharides of the marine algae as an anticancer agent in vitro against colon cancer cell line (CoCa2) and breast cancer (MCF7) cell lines and to measure lactate dehydrogenase enzyme (LDH) activity as biomarker of membrane integrity of the cells. Methods: The cells of breast cancer (MCF7) and colon cancer (CoCa2) were used to evaluate the potential anticancer role of the polysaccharides of marine algae. Anti-proliferative activity against MCF7 and CoCa2 cell lines were evaluated in vitro by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Results: The in vitro assay of the antioxidant activity of eight marine seaweed species showed that the red seaweed Jania rubens (J. rubens) had the highest DPPH (2,2 diphenyl-1-picrylhydrazyl) free radical scavenging activity. The extracted polysaccharides with concentrations 0.1–40.0 mg/mL from J. rubens were tested for its anticancer potentiality and cytotoxic effects against the cell lines of human breast (MCF7) and colon cancer (CoCa2) cell lines by MTT assay. The inhibitory concentration at 50 (IC50) value the of J. rubens polysaccharide extract was 0.312 5 mg/mL for MCF7 and 20 mg/mL for CoCa2. LDH activity and annexin V concentration were higher in the treated MCF7 and CaCo2 cells than in the untreated ones. Quantitative polymerase chain reaction technique indicated that the polysaccharide treatments caused up-regulation of Bax, caspase 8 and P53 genes expression in CoCa2 cells, and up-regulation of caspase 3 and down-regulation of Bcl2 genes expression in MCF7 cells. Conclusions: The polysaccharides of the red marine alga J. rubens could be a potential candidate for the natural compounds as antioxidant and anticancer therapy

Enhancement of Biochemical and Nutritional Contents of Some Cultivated Seaweeds Under Laboratory Conditions

<p>Six species of macroalgae belonging to the Chlorophyta, Phaeophyta, and Rhodophyta divisions were cultivated in a closed system with Guillard's f/2, Walne's, Provasoli Enriched Seawater (PES) medium, and seawater (control) for 6 weeks. The growth rate and parameters of the tested seaweeds showed that all used media enhanced the growth rate and chemical content as compared with other seaweeds cultivated in seawater without addition of any nutrients. There are significant differences in the effect of the used media on the seaweed composition at <i>p</i> = .01; PES is more effective than the f/2 and Walne's media. The results indicate that the cultivation technique of some macroalgae was an efficient tool for increasing the seaweeds' biomass and increasing their chemical compounds, calories, and energy under laboratory conditions.</p

Antimicrobial activity of some seaweeds species from Red sea, against multidrug resistant bacteria

This study evaluates the antibacterial activity of diethyl ether, methanol, ethanol and chloroform extracts of red algae Ceramium rubrum (Rhodophyta), Sargassum vulgare, Sargassum fusiforme and Padina pavonia (Phaeophyta) collected from Red sea, Egypt. The algal extracts were tested for their antibacterial activity against ten multidrug resistant clinical isolates of Gram positive and Gram negative bacteria. The highest inhibition activity among all extracts was obtained with 100 μl diethyl ether extract S. fusiforme against Staphylococcus aureus 2 and 50 μl ethanol extract of S. vulgare against Klebsiella pneumoniae. The algal extract of S. fusiforme and S. vulgare was characterized by Gas chromatography–mass spectrometry (GC–MS). The compounds with antimicrobial activity were identified, such as phenols, terpenes, acetogenins, indoles, fatty acids and volatile halogenated hydrocarbons. Transmission electron microscopy was applied for determining the morphological changes in S. aureus 2 and K. pneumonia treated with 100 μl diethyl ether extract of S. fusiforme and 50 μl ethanol extract of S. vulgare, respectively. Perforation of cell wall, leakage of cytoplasmic contents, severe distortion of outer cell shape, inner chromatin mild scattered cytoplasmic vacuolation, rupture of cell wall, and decreased cell size for both bacterial isolates treated with 100 μl diethyl ether of S. fusiforme extract and 50 μl S. vulgare ethanolic extract were recorded

Protective effects of Spirulina on the liver function and hyperlipidemia of rats and human

In the present study, the effects of Spirulina on subchronic treatments (two weeks) of hyperlipidemia and liver function of the rats and humans were investigated. The hyperlipidemia was induced in the rats using 25% of soya bean oil and 25% butter. The butter induced more hyperlipidemia than soya bean oil. Spirulina was used at the concentrations of 0, 2.5, 5.0 and 10 % of diet weight of the rats. The decrease in hyperlipidemia by Spirulina was dependent on its concentration in the diet. In case of human studies, about four g/day of Spirulina was taken via oral administration by Egyptian volunteers patients with hyperlipidemia. Spirulina decreased the levels of hyperlipidemia in these patients. The effects were dependent on the amount and number of administered dose of Sprirulina. The results suggested that the Spirulina treatment could induce marked reduction of aminotransferase through correcting lipid profile and increasing high density lipoprotein

Synergistic antibacterial effects of Ulva lactuca methanolic extract alone and in combination with different antibiotics on multidrug-resistant Klebsiella pneumoniae isolate

Abstract Various antibiotics are available, including gentamicin, chloramphenicol, ampicillin, amoxicillin, and streptomycin, but they have some restrictions. Many microorganisms are resistant to these medications. A new antimicrobial source must be found or developed to solve this issue. Inhere, extract from seaweeds Ulva lactuca was investigated for its antibacterial activity using a well diffusion assay against Klebsiella pneumoniae, and a promising inhibition zone diameter was recorded to be 14.04 mm. The biochemical structure of the antibacterial compound was determined via GC-MS and FTIR analysis. Also, a micro-dilution assay was used to calculate the minimum concentration that makes inhibition (MIC) to be 1.25 mg/ml from U. extract reliable to prevent the visibility of any bacterial growth, this was followed by examining the antibacterial effect of U. Lactuca methanolic extract alone and the synergetic effect of U. Lactuca methanolic extract in combination with two different antibiotics (gentamicin and chloramphenicol). This was assayed by the agar well diffusion method to achieve promising and strong inhibiting power against K. pneumoniae. It was deduced that the maximum synergism could be achieved by adding 2.5 mg/ml of Ulva methanolic extract to gentamicin (4 µg/ml), and the results were illustrated obviously via transmission electron microscope in which severe morphological deteriorations were experienced by the treated cells. From this study, we can conclude that U. lactucae extract has the power to aid antibiotics in reducing the growth of pathogenic K. pneumoniae