Antibacterial activities of bioactive compounds extracted from Marine algae Gracilaria salicornia against Aeromonas hydrophila

Herbal medicinal products have attracted significant research interest in recent years. Considering the efficiency of algae products in controlling pathogenic bacteria and also easy access to large resources of algae, this study was conducted to evaluate the effects of methanolic, chloroformic and aqueous extracts of Gracilaria salicornia against Aeromonas hydrophila, a heterotrophic, Gram-negative, rod-shaped bacterium found mainly in warm climate. Algae samples were collected from Qeshm Island coastlines and transferred to the laboratory. Standard methods were used to obtain the algae extract. Antibacterial activities of various extracts were tested against the bacterium using well diffusion assay method. Significant differences were observed in antibacterial activities of different extracts (P<0.05). The diameter of zone of growth inhibition varied in correlation with concentration of the extracts (50, 100, 200 and 300 mg.ml-1). The best inhibition zone was observed at 100, 200 and 300 mg.ml-1 methanolic and 300 mg.ml-1 aqueous extracts

Establishment of herbarium (stock collection) of the algae of the southern part of the Caspian Sea

The algal herbarium was set up and put into operation officially since 22 August 1993 at the Ghazian research station of the Gilan Fisheries Center. Several samplings were carried out from different regions of the Anzali Lagoon and Parts of the Southern shores of the Caspian Sea. The Samples Collected are being stored in the Laboratory in Living and non-Living form. 163 Living samples of 23 phytoplankton species are stored in the form of different types of inoculants liquid media and agar Plates. The species collected are as follows: Nodularia sp1, Nodularia sp2, Spirulina sp. Oscillatoria sp., Anabaena sp1,Anabaena sp2, Dactylococcopsis raphidiodes Lyngbia sp., Ankistrodesmus falacatus, Ankistrodesmus sp., Scenedesmus abundans S. acuminatus, S. obliquus, S. quadricada, Chlorella vulgaris Thalassionema nitzschioides, Cyclotella sp., Rhizosolenia calcar avis, Navicula sp., Bacillaria sp. Pure cultures of seven phytoplankton species have been developed which include: Scenedesmus abundans, S.obliquus, S. acuminatus, S. quadricada, Chlorella vulgaris, Spirulina sp.and Ankistrodesmus falcatus. The non-Living samples are stored dried or fixed in suitable Preservatives. More than 200 phytoplankton specimens are available in the Laboratory at present, of which 100 species have been identified

In Vitro Assessment of Antimicrobial Activities of Ether and Hexane Extracts of microalgae Chlorella vulgaris against pathogenic bacteria

Introduction:Increasing trends of drug-resistant strains of microorganisms especially bacteria have urged scientists to seek for antimicrobial compounds in natural resources with minimal or negligible side effects. Microalgae are one of these natural resources which are rich in active metabolites with potential use in pharmaceutical industries. Materials and methods: In this studyChlorella vulgaris was collected from microalgae collection of the International Sturgeon Institute- Rasht- Iran. Antibacterial activities of hexane and ether extracts of C. vulgaris against gram-positive bacterium Bacillus subtilis and Gram-negative bacterium Aeromonas hydrophila were evaluated. Algae was purely cultured to obtain the required volume and cell concentration for experiment and then the prepared biomass were extracted and Cannell et al. (1988) methods were used to examine antibacterial activities of hexane and ether extracts of the algae (1). Results: The results of the study approvedinhibitory properties of hexane and ether extracts of C. vulgaris against A. hydrophila and B. subtilis bacteria. The diameter of inhibition zone of hexane extract against B. subtilis and A. hydrophila, were 11-15.6 and 9.6- 11 mm and for ether extract were 12-18.6 and 7.6-16 mm respectively. Gas chromatography mass spectrophotometry was used to identify different substances in diethyl ether and hexane extracts. The main substances in ether extract included ketone compounds, esters, hydrocarbons, siloxane, Saylyl, terpenes and Hydrvsaylyl polyesters and in hexane extract the main substances were hydrocarbons, siloxane, Saylyl and Hydrvsaylyl are polyester. Discussion and conclusion: The inhibitory effect of ether extract was higher than the hexane extract therefore it could be used as a solvent to extract antimicrobial compounds

Pollution evaluation in the Shahrood River: do physico-chemical and macroinvertebrate-based indices indicate same responses to anthropogenic activities?

This study evaluates the impact of anthropogenic activities on the Shahrood River using water physico-chemical variables and macroinvertebrates data sets obtained over a period of 12 months between February 2012 and February 2013 at 8 sampling sites. Biotic indices i.e. FBI and BMWP based on macroinvertebrates and physico-chemical indices (MPI, HPI and NSF-WQI) were employed to evaluate the water quality status in connection with natural- and human-induced pressures. Based on physico-chemical indices, water quality was categorized as low polluted level and it is suitable for drinking purposes. The water quality based on biotic indices was related to the anthropic activities; a clear deterioration of the water quality was observed from upstream to downstream sites. The water quality along the river changed from very good (class I; reference sites) to good (class II; midstream sites) and turned into moderate (class III) and poor (class IV) quality (downstream sites). These findings indicate that biotic indices are more powerful indicators in assessing water quality than physico-chemical indices. Allocapnia, Glossosoma and Hesperoperla were exclusively related to least disturbed sites, and Naididae, Orthocladiinae and Ecdyonurus were found in sites showing notable degradation. Our results recommended that the use of macroinvertebrates could be employed as a cost-effective tool for biomonitoring and controlling of polluted riverine ecosystems in the Middle East. Finally, the results from this study may be useful not only for developing countries, but also for any organization struggling to use macroinvertebrate based indices with restricted financial resources and knowledge

Distribution of benthic centric diatom Pleurosira laevis (Compère, 1982) in different substrate type and physical and chemical variables

Abstract: Aim This contribution reports the first regional occurrence of Pleurosira laevis in the Masuleh River, Iran and additionally describes the pattern of occurrence along the Masuleh River and among four substrate types. The aim of this study was to assess the effects of substrate type and physical and chemical variables on distribution of centric diatom P. laevis. Methods At each station, triplicate samples were collected from 4 substrata. Epilithic (assemblages on rock), epidendric (assemblages on wood), epipsammic (assemblages on sand), and epipelic (assemblages on mud) diatom and water quality sampling was done four times at 5 stations. Physical and chemical variables including total nitrate, total phosphate, silicate, Fe2+, EC, and pH were also determined. Samples preserved in 2% for formalin solution and transferred to the laboratory, boiled with acid (HNO3: H2SO4; 2:1), centrifuged, identified, and counted. Cluster analysis was performed to indicate the main differences and similarities in diatom abundance amongst substrates sampled and amongst sampling stations. Results The highest (12.54 ± 1.54) and lowest (0.74 ± 0.10) abundance was obtained from wooden and muddy substrates at stations S5 and S4, respectively. The highest abundance was observed in the wooden substrate among all of sampling stations where showed significant differences (P 0.05). Conclusion We conclude that wood substrata can be substituted for one another during field surveys. Results from this study demonstrate that the type and roughness of the substrate both influence the attachment of P. laevis and its subsequent growth conditions

Synthesis and biological evaluation of novel tetranuclear cyclopalladated complex bearing thiosemicarbazone scaffold ligand: Interactions with double-strand DNA, coronavirus, and molecular modeling studies

International audienceThreading intercalators are a novel class of materials that carry two substituents along the diagonal positions of an aromatic ring. When bound to DNA, these substituents project out in DNA grooves. Tetranuclear complexes appear to be promising threading intercalators for developing therapeutics against cancer and viral infections that require high nucleic acid binding affinity. The objective of this work was to prepare the thiosemicarbazone scaffold ligand [4-ClC6H4CHN=NC(S)NHPh] and tetranuclear cyclopalladated complex [Pd(4-ClC6H4CHN=NC(S)NHPh)4] and to characterize the compounds by elemental analysis, 1D and 2D NMR, HRMS, and IR spectroscopy. The calf thymus DNA (CT-DNA) binding properties of the compounds were investigated in vitro under simulated physiological conditions using UV-vis spectroscopy, emission spectral titration, methylene blue competitive binding, circular dichroism, DNA thermal denaturation, DNA binding, and coronavirus interactions using molecular simulation. The compounds showed cytotoxic effect against both human breast (MCF-7) and colorectal (HCT116) cancer cells in a dose-dependent manner. We demonstrated that the compounds are promising for DNA threading intercalation binders with large DNA binding constants on the order of 107 M1 magnitude

Reduction of toxic organic dyes in aqueous media using N-heterocyclic copper(II) complex immobilized on the beta-cyclodextrin-modified Fe3O4 nanoparticles as a magnetically recyclable catalyst

This study was undertaken to design a stable easy-recoverable nanoadsorbent (Fe3O4@CM-β-CDP@Tet-Cu(II)) hybrid with rich catalytic sites via wet-chemical method for the catalytic reduction of toxic dyes in wastewater. β-cyclodextrin (β-CD) with a hydrophilic character outside and hydrophobic inside cavity play an important role in catalytic reduction process by interacting with organic molecules and also prepared more sites for further surface modifications. Several characterization techniques including FT-IR, TGA analysis, FE-SEM/EDX, TEM, X-Ray diffraction patterns (XRD) measurements were employed to investigate the structural properties of the synthesized material. The catalytic ability of the obtained material was examined in the presence of different dyes including p-nitrophenol, Eosin Y, Rhodamine B, Congo red, and Methyl orange by UV–Vis spectroscopy as a simple and available method. Moreover, the parameters which effect on reduction process, such as dye and reducing agent (NaBH4) concentrations, mass of adsorbent and time were optimized at room temperature. The obtained data demonstrate the considerable catalytic ability of Fe3O4@CM-β-CDP@Tet-Cu (II) besides a remarkable reduction rate and high yield over a short reaction time, in particular for Methyl orange dye. Recycling experiments revealed that Fe3O4@CM-β-CDP@Tet-Cu (II) has an excellent stability wherein the catalyst was recycled five times with a slight decrease in the reduction ability without any remarkable change in morphological properties which confirm by FE-SEM analysis. The high catalytic activity, the magnetic recoverability, along with the excellent stability of Fe3O4@CM-β-CDP@Tet-Cu (II) make it a potential candidate for the reduction of multiple dyes in real wastewater samples