Aqueous extracts of microalgae exhibit antioxidant and anticancer activities

Objective:To investigate the antioxidant and anticancer activities of aqueous extracts of nine microalgal species.Methods:Variable percentages of major secondary metabolites(total phenolic content,terpenoids and alkaloids) as well as phycobiliprotein pigments(phycocyanin, allophycocyanin and phycoerythrin) in the aqueous algal extracts were recorded.Antioxidant activity of the algal extracts was performed using 2,2 diphenyl-1-picrylhydrazyl(DPPH) test and 2,2'azino-bis(ethylbenzthiazoline-6-sulfonic acid(ABTS.) radical cation assay.Anticancer efficiency of the algal water extracts was investigated against Ehrlich Ascites Carcinoma cell(EACC) and Human hepatocellular cancer cell line(HepG2).Results:Antioxidant activity of the algal extracts was performed using DPPH test and ABTS.^+ radical cation assays which revealed 30.1-72.4%and 32.0-75.9%respectively.Anticancer efficiency of the algal water extracts was investigated against Ehdich Ascites Carcinoma Cell(EACC) and Human Hepatocellular cancer cell line(HepG2) with an activity ranged 87.25%and 89.4%respectively.Culturing the promising cyanobacteria species;Nostoc muscorum and Oscillatoria sp.under nitrogen stress conditions(increasing and decreasing nitrate content of the normal BG11 medium,1.5 g/L),increased nitrate concentration(3,6 and 9 g/L) led to a remarkable increase in phycobilin pigments followed by an increase in both antioxidant and anticancer activities in both cyanobacterial species.While the decreased nitrate concentration(0.75,0.37 and 0.0 g/L) induced an obvious decrease in phycobilin pigments with complete absence of allophycocyanin in case of Oscillatoria sp.Conclusions:Nitrogen starvation(0.00 g/L nitrate) induced an increase and comparable antioxidant and anticancer activities to those cultured in the highest nitrate content.

Acaricidal activity of different extracts from Syzygium cumini L.Skeels(Pomposia) against Tetranychus urticae Koch

Objective:To investigate the acaricidal activity of different extracts from Syzygium cumini(S.cumini)(Pomposia)againsst Tetranyckus urticae Koch(71 urticae)and the biochemical changes in antioxidants enzymes.Methods:Six extracts of S.cumini(Pomposia)at concentrations of 75,150 and 300μg/mL were used to control T.urticae(Koch).Results:The ethanol extract showed the most efficient acaricidal activity agent against T.urticae(98.5%)followed by hexane extract(94.0%),ether and ethyl acetate extract(90.0%).The LC_(50)values of the promising extract-were 85.0,101.0,102.0 and 98.0μ/mL,respectively.The activities of enzymes including ascorbate peroxidase(APX),peroxidase(POD),superoxide dismutase(SOD)and catalase(CAT)in susceptible mites were increased.The activities of all antioxidant enzymes reach the maximum value in mites at LC_(50)with ethanol and ethyl acetate extracts,respectively.Conclusions:The extract of S.cumini has acaricidal acivity against T.urticae,and the ethanol extract is the most efficient.

Prospects of effective microorganisms technology in wastes treatment in Egypt

Sludge dewatering and treatment may cost as much as the wastewater treatment.Usually large proportion of the pollutants in wastewater is organic.They are attacked by saprophytic microorganisms,i.e.organisms that feed upon dead organic matter.Activity of organisms causes decomposition of organic matter and destroys them,where the bacteria convert the organic matter or other constituents in the wastewater to new cells,water,gases and other products.Demolition activities,including renovation/remodeling works and complete or selective removal/demolishing of existing structures either by man-made processes or by natural disasters,create an extensive amount of wastes.These demolition wastes are characterized as heterogeneous mixtures of building materials that are usually contaminated with chemicals and dirt.In developing countries, it is estimated that demolition wastes comprise 20%to 30%of the total annual solid wastes.In Egypt,the daily quantity of construction and demolition(C&D) waste has been estimated as 10 000 tones.That is equivalent to one third of the total daily municipal solid wastes generated per day in Egypt.The zabbaliin have since expanded their activities and now take the waste they collect back to their garbage villages where it is sorted into recyclable components:paper,plastics, rags,glass,metal and food.The food waste is fed to pigs and the other items are sold to recycling centers.This paper summarizes the wastewater and solid wastes management in Egypt now and future.