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Background: Nanobiotechnology is a cutting-edge field that is revolutionizing the way we produce and utilize nanoparticles. With bacteria becoming increasingly resistant to traditional antibiotics, researchers are exploring new ways to synthesize antimicrobials. Objective:: The aim of this study was to investigate the biosynthesis of different forms of silver nanoparticles using different biological methods from Microcystis sp. to be used as an antimicrobial agent. Methods: We employed the direct strain powder method, ethanolic extract pellets, and ethanolic extract. Then a combination of analytical techniques was used to characterize the properties of nanoproperties. Finally, we evaluated the antimicrobial activity of the AgNPs against a panel of bacteria and fungi. Results: AgNPs were found in various forms, such as cubic, spherical, and rod shapes. UV-Vis detected a peak at 420 nm, and SEM identified the AgNPs with bio-capped layers ranging from 40-130 nm. The antibacterial test revealed that the pellet method produced the most effective AgNPs, specifically against Gram-positive bacteria such as Staphylococcus sp. with a clear zone of 32 mm, while the larger cubic AgNPs produced by the powder method were less effective as antibacterial agents. Conclusion: This study demonstrates that AgNPs can be produced using Microcysts sp. as a reducing and capping agent; furthermore, they are produced in different shapes as cubic, spherical, and rod shapes. Besides that, cubic nanoparticles are more effective in killing germs than spherical ones. The results of this study will help to improve our understanding of the mechanisms of AgNPs biosynthesis and pave the way for the development of new and more effective antimicrobial agents.

The exploration of novel therapeutic agents and other bioactive secondary metabolite from Streptomyces species, for possible agricultural farming, pharmaceutical and industrialized applications, has been, and still is, essential. The existing studies were aimed with biologically potential Streptomyces species and its antagonistic activity against dreadful microorganisms. Totally, morphological three different actinomycetes were selected from the fertile agricultural lands. Among the three, the isolate SA4 exhibited significant antimicrobial and anti-nematicidal activity towards selected microbial pathogens such as E Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, Salmonella typhi, Bacillus subtilis, Proteus vulgaris, Shigella flexineri, Candida albicans, and Fusarium sp. The prospective strain SA4 was identified as Streptomyces cuspidosporus. The isolate SA4 optimized for secondary metabolites production with International Streptomyces project 4 (ISP 4) medium, pH 7.0 at 37 °C for 14 days. Gas Chromatography-Mass spectrometry (GCMS) analysis of strain SA4 bioactive extract publicized the existence of 1,2-Benzenedicarboxylic acid, bis(2-Methylpropyl) ester compound and occupied by high peak area and its possessed significant biological properties.

Silver nanoparticles (AgNPs) are gaining considerable importance due to their attractive physicochemical properties for many applications. In the present study, (Ag NPs) were synthesized by the reduction of aqueous solutions of silver nitrate (AgNO3) with powder and solvent extracts of Padina pavonia (brown algae). The obtained nanoparticles exhibited high stability, rapid formation of the biogenic process (2 min -3 h), small size (49.58–86.37 nm) (the diameter of formed nanoparticles was measured by TEM and DLS) and variable shapes (spherical, triangular, rectangle, polyhedral and hexagonal). Preliminary characterization of nanoparticles was monitored by using UV–visible spectroscopy (UV–vis), Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS) and finally by Fourier Transform Infrared spectroscopy (FTIR). The ratios of converted Ag NPs were recorded as 88.5; 86.2 and 90.5% in case of P. pavonia powder. extract and chloroform extract, respectively. Keywords: Biogenic, AgNPs, Padina pavonia

Graphical abstract, The exploration of novel therapeutic agents and other bioactive secondary metabolite from Streptomyces species, for possible agricultural farming, pharmaceutical and industrialized applications, has been, and still is, essential. The existing studies were aimed with biologically potential Streptomyces species and its antagonistic activity against dreadful microorganisms. Totally, morphological three different actinomycetes were selected from the fertile agricultural lands. Among the three, the isolate SA4 exhibited significant antimicrobial and anti-nematicidal activity towards selected microbial pathogens such as E Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, Salmonella typhi, Bacillus subtilis, Proteus vulgaris, Shigella flexineri, Candida albicans, and Fusarium sp. The prospective strain SA4 was identified as Streptomyces cuspidosporus. The isolate SA4 optimized for secondary metabolites production with International Streptomyces project 4 (ISP 4) medium, pH 7.0 at 37 °C for 14 days. Gas Chromatography-Mass spectrometry (GCMS) analysis of strain SA4 bioactive extract publicized the existence of 1,2-Benzenedicarboxylic acid, bis(2-Methylpropyl) ester compound and occupied by high peak area and its possessed significant biological properties.

Microalgae sorbents are microalgae that have the potential to passively bind heavy metals/contaminants to their cellular structures in a process called biosorption. This study investigates the use of two species of microalgae to remove the toxic heavy metal cobalt from aqueous solution. Two microalgae isolates, Phormidium tenue and Chlorella vulgaris, were collected from the Wadi Hanifah Stream in Riyadh, the Kingdom of Saudi Arabia. We determined the capacity of both isolates to bioremove Co+2 ions and the optimum conditions under which this occurs. The two isolates were additionally characterized by microscopic and Fourier transform infrared spectroscopy (FTIR). In the current investigation, Phormidium tenue removed 94% of Co+2 under ideal conditions of pH 6, contact duration (30 min), starting concentration (50 mgL−1) and biosorbent dose (1gL-1); while Chlorella vulgaris removed 87% of Co+2 under the same parameters except pH 5.5 and contact duration (60 min). Fourier transform infrared spectroscopy (FTIR) confirms the binding of Co+2 to the biomass, which comprises many of the functional groups. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed some alterations to the shape of algal cells and cellular components for both microalgae studied. In addition, equilibrium study by both Langmuir and Freundlich models was performed to detect the effect of certain equilibrium factors on the capacity of the biosorption mechanism. Finally, Phormidium tenue and Chlorella vulgaris were discovered to be promising microalgae for effective cobalt biosorption in aquatic conditions.

The hexavalent chromium Cr(VI) poses a threat as a hazardous metal and its removal from aquatic environments through biosorption has gained attention as a viable technology of bioremediation. We evaluated the potential use of three green algae (Cladophora glomerata, Enteromorpha intestinalis and Microspora amoena) dry biomass as a biosorbent to remove Cr(VI) from aqueous solutions. The adsorption capacity of the biomass was determined using batch experiments. The adsorption capacity appeared to depend on the pH. The optimum pH with the acid-treated biomass for Cr(VI) biosorption was found to be 2.0 at a constant temperature, 45 °C. Among the three genera studied, C. glomerata recorded a maximum of 66.6% removal from the batch process using 1.0 g dried algal cells/100 ml aqueous solution containing an initial concentration of 20 mg/L chromium at 45 °C and pH 2.0 for 60 min of contact time. Langmuir and Freundlich isotherm equations fitted to the equilibrium data, Freundlich was the better model. Our study showed that C. glomerata dry biomass is a suitable candidate to remove Cr(VI) from aqueous solutions. Keywords: Bioremediation, Cr(VI), Green algae, Water pollution

Bio-synthesis of AgNPs (silver nanoparticles) by using of the dry and solvent extract of red marine alga Laurencia catarinensis was conducted in the present work. Characterizations of the formed AgNPs was approved by UV–Visible Spectroscopy, Transmission Electron Microscopy, Dynamic Light Scattering and finally by Fourier Transform Infrared spectroscopy. We achieved the synthesis of AgNPs by the reduction of aqueous solutions of AgNO 3 with the powder and extract of Laurencia catarinensis . Bio-synthesis of Ag nanoparticles was confirmed by visual inspection. The obtained algal nanoparticles were characterized by highly stable formation, short time of the biogenic process (2 min-3 h), small size (39.41–77.71 nm) with several shapes (spherical, triangular, rectangle, polyhedral and hexagonal).

Marine macroalgae are plant-like organisms with simple internal structures that generally live in coastal areas. They mainly include different communities of red, brown and green macroalgae. Marine macroalgae commonly occupy intertidal and sublittoral-to-littoral zones on rocks and other hard substrata. They are considered to be an excellent natural biosource in different aspects of agricultural fields. They have great proficiency in improving soil physical and chemical properties. Marine macroalgae are also characterized by producing a large array of biologically active biocidal substances against plant-infecting pathogens. Unfortunately, most available literatures on marine macroalgae and their derivatives mainly focused on their pharmaceutical applications but their potential utilization in sustainable agriculture development is still often regarded as a secondary goal. However, a relatively considerable dataset on marine macroalgae showed that they could play a major role in plant protection and improvement. This review summarizes different aspects of potential macroalgal applications in agriculture. Commercial production and exploitation of specific compounds with interesting biotechnological importance from marine macroalgae including microbicides, nematicides, insecticides, biofertilizers, biostimulators and soil conditioners are highlighted and discussed in detail. Bioactive compounds like fatty acids (in particular polyunsaturated fatty acids (PUFAs), proteins (amino acids), bioflavonoids, sulfated polysaccharides, carotenoids, polyphenols and carbohydrates are considered to have bactericidal, antiviral and fungicidal effects against some plant-infecting pathogens. These biocontrol agents provide multiple benefits and act as useful pointers for improving cultivation practices in diverse habitats. Marine macroalgae can be generally considered as promising multifunctional bioinoculants and ecofriendly environmental tools in recent trends of organic farming.

In the present investigation, an antihyperlipidemic activity of Cladophora koeiei ethanol extract against six pathogenic bacteria was conducted. Also, we evaluate the activity of the alga extract against hyperlipedemia in the administrated albino rates through measuring the blood lipid profiles [triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL-C), high-density lipoprotein cholesterol (HDL-C), cholesterol] and induced hepatic damage by measuring the contents of creatinine, total proteins, blood urea nitrogen (BUN), albumin and globulin and diagnostic marker enzymes such as aspartate aminotransaminase (AST) and alanine aminotransaminase (ALT). Alga extract proved efficient activity against the tested bacteria ranged between medium and high suppression action. Results revealed also, the efficiency of C. koeiei extract in the decreasing the triglycerides (TG), total cholesterol (TC), low-density lipoproteins (LDL-C), blood urea nitrogen (BUN) and creatinine caused by alcohol. However, the treatment by alga extract exhibits high-density of lipoproteins (HDL-C) (beneficial), total protein, albumin, and globulins. Also, the algal treatments masking the lethal effects caused by harmful alcohol from raising the rate of enzymes ALT, AST, which returned to the normal state in the groups treated with alga extract. Our findings provide the evidence that new natural antioxidant substances can be present in the C. koeiei extract and hence this alga proves to be effective as a source for therapeutic agents.

MARINE algae contain a variety of bioactive secondary metabolites and several compounds have been derived from them for prospective development of novel drugs by the pharmaceutical industries. In this laboratory experiment Cystoseira barbata was isolated from Red Sea coastal water (Safaga, Egypt). It was evaluated due to its bioactivities potential. Where the algal extract proved a potent activity against bacterial and fungal strains ranged between medium and high suppression action. It showed that Gram positive bacteria Bacillus subtilis and Staphylococcus aureus were more sensitive than Gram negative bacteria where Serratia marcescens, Pseudomonas aeuroginosa and fungus Candida albicans. Phyto-chemical analyses showed that C. barbata recorded the highest percentages of the flavonoids, phenols and saccharides compounds. Among the bioflavonoids determined Acacetin, Kaemp.3-(2-p-comaroyl) glucose, Rosmarinic and phenols were E-Vanillic, Benzoic and Ferulic were present in high percentages in the alga analyzed. The results indicated scope for utilizing this alga as a source of antibacterial and antifungal substances.

IN THIS CONTEXT the brown alga Dictyota dichotoma isolated from Hurghada Sea-Shore, Red-Sea coast, Egypt (June 2015) was screened for its antimicrobial bioactivity. A laboratory experiment was conducted to test activity of ethanol extract of the brown alga Dictyota dichotoma against three types of Gram- positive and six of Gram-negative bacteria, and one type of fungi. Ethanol extract was selected for this study by using different concentrations (100, 200, 300, 400 mg) of alga extracts. Result revealed that the alga ethanolic extract exhibited high suppression activity against all tested pathogens. HPLC analysis of the chemical composition of algal extract was detect the presence of high amount of certain ingredients such as Flavonoids (Acacetin, Luteo.6-arabinose8-glucose, Naringin, Hespirtin, Rosmarinic and Naringenin by 3448.407, 453.209, 396.107, 387.429, 213.689 and 207.17 ppm, respectively) and Phenols (Benzoic, E-Vanillic, Pyrogallol, Catechein, Salycilic and Ellagic by 1075, 912, 785, 628 and 357 ppm, respectively). The present finding revealed that the tested alga can be used as possible natural source of active ingredients.

Aims: This study aimed to analyze the bioactivities of two different species of marine red algae crude extracts; Acanthophora spicifera (M.Vahl) Borgese and Digenea simplex (Wulfen) C.Agardh. Place and Duration of Study: Sample: Quseir city, Red Sea, Egypt at (April, 2015), extraction and biological study; pharmacognosy department, summer 2015, Kasr El-Eini Teaching Hospitals, Cairo University, Egypt. Methodology: The crude extract screened against some human pathogenic bacteria including ten Gram positive, ten Gram negative strains and ten unicellular and filamentous fungi. The antimicrobial activity was done through the agar well diffusion method. The anti-inflammatory effect of the crude extract on inflammed liver cells was evaluated by measuring SOD, MDA, catalase, GSH, Il-6 and TNF-alpha in the serum of treated Wister albino rats compared to positive and negative control groups. Results: The antimicrobial study showed that both Acanthophora spicifera and Digenea simplex extracts showed the highest zone of inhibition against Streptococcus agalactiae with clear zones (22.5±0.58 mm and 23.1±0.58 mm) as Gram positive bacteria compared to Ampicillin as positive control. But with Gram negative bacteria Acanthophora spicifera showed highest zone of inhibition against Pseudomonas aeruginosa (22.3±2.1 mm) and Digenea simplex showed highest zone of inhibition against Serratia marcescens (24.1±0.58 mm) compared to Gentamycin as positive control. Finally, the effect of both Acanthophora spicifera and Digenea simplex against fungi showed highest zone of inhibition (23.8±0.63 mm and 22.4±2.1 mm) against Geotricum candidum. On the other hand results revealed that all methanol extracts had equally potent anti-inflammatory effects on inflammated liver rats as it observed significant decreased in the levels of SOD, Catalase and GSH. Also observed that significant increase in the inflamed liver state of MDA, IL-6 and TNF-Alpha After treatment of inflamed liver rats with crude extracts observed that the difference in the parameters levels relatively equal to the normal control results. Conclusion: Acanthophora spicifera (M.Vahl) Borgeseand Digenea simplex (Wulfen) C.Agardh might be a good source of anti-inflammatory and antibacterial compounds activity.

A laboratory experiment was conducted to test antibacterial activity of ethanol extract of the brown alga Hormophysa cuneiformis against three types of Gram- positive and three of Gram-negative bacteria, where extracts of this alga proved efficient activity against these pathogenic bacteria species ranged between medium and high suppression action. Also, we evaluated the effects of H. cuneiformis ethanolic extract and its major constituents on the serum lipid and protein levels of hyperlipidemic rats induced by the administration of a high cholesterol diet. Results revealed the efficiency of H. cuneiformis extract in the decreasing the levels of the total cholesterol (TC), triglycerides (TG), low-density lipoproteins (LDL-C), blood urea nitrogen (BUN) and creatinine caused by alcohol. On the other hand, the treatment by alga extract exhibit significant increase in the high-density lipoproteins (HDL-C) (beneficial), total protein, albumin and globulins. The algal treatments also masking the lethal effects caused by harmful alcohol from raising the rate of enzymes ALT, AST, which returned to normal state in the groups treated by alga extract. Also, the histopathological examination of the ethanol treated groups of rate revealed degeneration and necrotic changes as compared to the administrated rate groups with alga extract which showed marked amelioration of the severity of these changes.

The marine algal flora of the Umluj city received no attention about the marine macroalgae. In this paper a total of 19 species are reported for the first time as occurring in the Umluj coast of Saudi Arabia. These species related to Chlorophyta (1), Phaeophyceae (6) and Rhodophyceae (12).

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), (1) H and (13) C NMR, proton-proton correlation spectroscopy ((1) H-(1) H 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.

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.

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), (1) H and (13) C NMR, proton-proton correlation spectroscopy ((1) H-(1) H 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.

Five cyanobacterial species (Phormidium sp., Nostoc sp., Anabaena sp. Aphanothece conferta, and Synechocystis aquatilis) isolated from the Suez Canal coast at the city of Ismailia (Egypt) were tested for biodegradation of four hydrocarbon (HC) compounds: two aliphatic compounds (n-octadecane and pristine) and two aromatic compounds (phenanthrene and dibenzothiophene). High degradation efficiencies for the two aliphatic compounds were measured for A. conferta (64% for n-octadecane and 78% for pristine) and S. aquatilis (85% for n-octadecane and 90% for pristane). However, the other biodegradation percentages ranged between weak and moderate percentages.

In this study, synthetic and biological soil conditioners were used to screen their abilities to improvise the barren soil characters. These soil conditioners based on treatment of barren soil samples with urea and / or compost as synthetic soil conditioner or by inoculating the soil samples with Spirulina meneghiniana Zanrd. ex Gomon and / or Anabaena oryza e Fritsch as a biological soil conditioner. The data revealed that, the biological conditioner in a mixture (22.5 kg ha -1 Anabaena and 22.5 kg ha -1 Spirulina supplied with 7.5 kg ha -1 urea and 7.5 kg ha -1 compost) was the most effective one. Also, the soil samples inoculated with this mixture exhibited positive activity of improving soil characters. Moreover, highly significant positive responses of the development features were appeared on lettuce plants transplanted in such soil samples.

Ten cyanobacterial species (Nostoc calcicola , N. commune, N. entophytum, N. minutum, N. palndosum, N. passerianum, N. punctiforme, Anabaena ambigua, A. amomala, and A. doliolum ) were isolated from the mangrove region of Ras Mohammed (Sinai, Egypt) and have been tested for their allelopathic activity that of 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 Nostoc 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

The synthesis of gold nanoparticles (Au) using Galaxaura elongata (powder or extract) is demonstrated here. The rapid formation of stable Au nanoparticles has been found using G. elong- ata extract in aqueous medium at normal atmospheric condition. Transmission electron microscopy (TEM) analysis revealed that the particles are spherical in shape along with a few rod, triangular, truncated triangular and hexagonal shaped nanoparticles. Zeta potential measurements indicated that the Au nanoparticles were in the size range of 3.85-77.13 nm. Fourier transform infrared spectroscopy (FTIR) showed that nanoparticles were capped with alga compounds. The chemical constituents, viz. Andrographolide, Alloaromadendrene oxide, glutamic acid, hexadecanoic acid, oleic acid, 11-eicosenoic acid, stearic acid, gallic acid, Epigallocatechin Catechin and Epicatechin gallate of the algal extract were identified which may act as a reducing, stabilizing and capping agent. The nanoparticles were also evaluated for their antibacterial activities which showed better antibacterial effects with maximum inhibition zones of 17-16 mm by AuNPs synthesized by ethanolic extract against Escherichia coli, Klebsiella pneumoniae and MRSA, respectively, followed by Staphylococcus aureus and Pseudomonas aeruginosa (13 mm). Furthermore, the nanoparticles synthesized by the powder of G. elongata were found to be highly effective against E. coli and K. pneumoniae (13.5 and 13 mm), respectively. On the other hand, the free ethanolic extract of G. elongata exhibits high activity only against MRSA (14 mm). a 2013 Production and hosting by Elsevier B.V. on behalf of King Saud University.

Extracts of four species of seaweeds, Ulva lactuca L. (green), Liagora farinosa Lamouroux (red), Padina pavonia L. and Turbinaria ornata Turn (brown), were screened for their antimicrobial, and antimalarial activities, and binding affinity for human opioid receptors. Phytochemical analysis led to the isolation and identification of 10 constituents: fucosterol, stearic acid, palmitic acid, palmitoleic acid, oleic acid, myristic acid, p-hydroxybenzoic acid, β-sitosterol, glycerol-1-olyl-3-palmotyl-2-galactoside, and glycerol-1,3-diolyl, The last two compounds displayed strong binding affinity to delta opioid receptors.

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.

The present study aimed to isolate β-amyrin for the first time from Laurencia microcladia Kutzing distributed at Dahab Coast, Aqaba Gulf, Egypt. The successive extraction of the ethanolic extract of the alga showed that, the petroleum ether extract was the best extractive solvent which contains the isolated active compound. Based on IR, MS, and 1H NMR analyses, the active principle is proposed to be triterpens having the empirical formula C30H50O with a melting point range 191–194 °C. The importance of this study was to draw attention and study the economic importance of different types of marine algae that grow on the Egyptian shores as they contain varying antimicrobial effectiveness. β-Amyrin obtained in this study from L. microcladia was known for its potent antibacterial activity and commonly used medically in many areas. These results provide evidence, to intensify the study on this L. microcladia to be used as a source of β-amyrin.