Neveen Abdel-Raouf

Microalgae and wastewater treatment.

Organic and inorganic substances which were released into the environment as a result of domestic, agricultural and industrial water activities lead to organic and inorganic pollution. The normal primary and secondary treatment processes of these wastewaters have been introduced in a growing number of places, in order to eliminate the easily settled materials and to oxidize the organic material present in wastewater. The final result is a clear, apparently clean effluent which is discharged into natural water bodies. This secondary effluent is, however, loaded with inorganic nitrogen and phosphorus and causes eutrophication and more long-term problems because of refractory organics and heavy metals that are discharged. Microalgae culture offers an interesting step for wastewater treatments, because they provide a tertiary biotreatment coupled with the production of potentially valuable biomass, which can be used for several purposes. Microalgae cultures offer an elegant solution to tertiary and quandary treatments due to the ability of microalgae to use inorganic nitrogen and phosphorus for their growth. And also, for their capacity to remove heavy metals, as well as some toxic organic compounds, therefore, it does not lead to secondary pollution. In the current review we will highlight on the role of micro-algae in the treatment of wastewater.

ANTIMICROBIAL AND ANTIHYPERLIPIDEMIC ACTIVITIES OF ISOLATED QUERCETIN FROM ANABAENA AEQUALIS1

This study aimed to isolate quercetin (for the first time) from Anabaena aequalis Borge, which inhabits soil surface of Wadi El‐Alaqui Protectorate located in Aswan city, Egypt. The isolated compound showed significant antibacterial activity against the gram‐positive bacteria Sarcina maxima and Micrococcus kristinae, the gram‐negative bacterium Klebsiella pneumoniae, as well as against the filamentous fungus Aspergillus flavus. The isolated compound was identified as quercetin using the structure elucidation based on UV, electrospray ionization mass spectrometry (ESIMS), 1H and 13C NMR, proton–proton correlation spectroscopy (1H‐1H COSY), distortionless enhancement by polarization transfer (DEPT), heteronuclear single quantum coherence (HSQC), and heteronuclear multiple bond correlations spectrum (HMBC). Medium lethal dose (LD50) of the isolated compound and its side effects against hyperlipidemia induced by ethanol intake in albino rats were carried out. No deaths were reported in rats within 72 h, which suggests that the isolated compound plays a beneficial role as an antihyperlipidemic agent in the treatment of alcohol‐induced hepatic tissue damage, which can be described as one of the therapeutic values.

Antimicrobial and antiviral activities against Newcastle disease virus (NDV) from marine algae isolated from Qusier and Marsa-Alam Seashore (Red Sea), Egypt

Diethyl ether, acetone and ethanol extracts of ten marine macroalgae; two belonging to Chlorophyceae ( Ulva lactuca and Caulerpa racemosa ), two belonging to Rhodophyceae ( Acanthophora spicifera and Galaxaura elongata ) and six taxa belonging to Phaeophyceae ( Liagora farinosa , Cystoseira compressa , Cystoseira myrica , Hydroclathrus clathratus , Turbinaria ornata and Padina pavonia ) isolated from the inter tidal zone along Qusier Marsa-Alam seashore (Red Sea), Egypt, were evaluated for their antibacterial, antifungal and antiviral activities against 3 Gram-positive bacteria ( Bacillus subtilis , Staphylococcus aureus and Sarcina maxima ), 3 Gram-negative bacteria ( Pseudomonas aeruginosa , Escherichia coli and Klebsiella pneumonia ), one unicellular ( Candida albicans ) and two filamentous fungi ( Aspergillus flavus and Fusarium oxysporum ) and against the Newcastle sense Virus (NDV)-(Paramyxoviridae) which is responsible for acute respiratory distress in chicken. Data showed that some extracts recorded strong inhibitory activities than the reference antibiotics, while others were with moderate and/or week inhibitory activities. However, many were without any inhibitory effects. The cytotoxicity effect of the tested algal extracts on chicken embryo showed that both diethyl ether and acetone extracts had toxic effects, but the ethanol extracts had no toxic effect, so that the ethanol extract was considered to be the most suitable for further studies. The antiviral activities of the ethanol extracts against NDV (Newcastle disease virus) showed that seven of the ten tested algal extracts have strong activities against NDV. Keywords: Antimicrobial and antiviral activities, Newcastle disease virus (NDV), marine macroalgae, Qusier and Marsa-Alam, Red Sea, Egypt

Cyanobacterial extra-metabolites against some pathogenic bacteria

Ten cyanobacterial species ( Nostoc calcicola , Nostoc commune, Nostoc entophytum, Nostoc minutum, Nostoc palndosum, Nostoc passerianum, Nostoc punctiforme, Anabaena ambigua, Anabaena amomala, and Anabaena doliolum ) were isolated from the mangrove region of Ras Mohammed (Sinai, Egypt), and were tested for their allelopathic activities including inhibitory and/or promoting effects against two Gram positive bacteria ( Bacillus subtilis and Staphylococcus aureus ) and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa ). Data suggested two types of allelopathic effects: one type which always appeared in cyanobacterial medium as in the case with N. minutum (medium that inhibits the growth of all tested bacterial species). The other type is induced only when cyanobacteria are in contact with bacteria; this is the case when the growth of both B. subtilis and S. aureus were inhibited in co-culture with N. commune. On the other hand, promotion effects of bacterial growth were observed when grown in cyanobacterial metabolites in most of studied cyanobacterial species. The biological assays for aqueous and methanolic extracts of the two Nostoc species revealed that both extracts for each species were not toxic at concentrations of 0.52 and 0.59 g L -1 water extract for N. commune and N. minutum , respectively and 0.31 and 0.425 g L -1 for methanolic extract for N. commune and N. minutum , respectively. No mortality was observed in tested mice within 72 h.

Harmful effects of endosulfan treatment on cyanobacterial distribution and some macromolecules of soybean plant.

In a trial to evaluate the impact of one of the commonly used insecticides in Egypt, a plot area cultivated with soybean was sprayed with endosulfan. Some of the biochemical criteria of the treated soybean and the biodiversity and biochemical activity of its companion cyanobacteria were compared with those of the untreated ones. The results revealed that endosulfan application caused inhibition in the attendance and biodiversity of the soil cyanobacteria found in the rhizosphere of the treated soybean, specially the filamentous species. The treated soil showed a highly significant inhibition in their ARA (acetylene-reducing activity) and exopolysaccharides. The biochemical analysis showed a high significant decrease in all the carbohydrate fractions as well as DNA and RNA contents of the treated soybean plants compared with the untreated ones. However, the total soluble proteins significantly Increased, indicating some defense pattern against the lethal effects of endosulfan. From the results, it could be concluded that application of endosulfan has a significant potential to change ecosystems and soil biological processes and could potentially reduce future farm productivity and cause harmful impact to agriculture.