Evaluation of biofilm formation and expression of psl, pel, alg genes of Pseudomonas aeruginosa in exposure to detergents.

Pseudomonas aeruginosa has been in the center of attention for several years as an opportunistic human pathogen implicated in many severe acute and chronic infections particularly in immunocompromised patients. Its high persistence and resistance against many antimicrobial agents are mostly attributed to biofilm formation. Biofilms are microbial communities mainly consisting of extracellular polymeric substances that encapsulate bacteria together and protect them from extracellular stresses. This cell aggregation is a stress response that P. aeruginosa employes as a survival strategy during growth with the toxic detergents. This process has shown to involve several operons such as psl, pel, and alg. Here we used P. aeruginosa strain PAO1 in control group, 40 P. aeruginosa strains from sink and 40 strains from surface of public places. Biofilm formation and gene expression were measured before and after exposure to sub minimum inhibitory concentration (sub-MIC) of biocides chlorhexidine diacetate and benzalkonium chloride. The qRT-PCR and biofilm formation results demonstrated an increase in biofilm formation ability and gene expression of pslA/B and pelA/B in two groups collected from sink and surface in contrast to the control group. A remarkable increase was observed in the biofilm formation and expression of pslA in the bacterial strain collected from the sink after exposure to biocides chlorhexidine diacetate. Both Pel and Psl appeared to have redundant functions as structural scaffolds in biofilms. Sub-MIC levels of detergents can improve biofilm formation ability of P. aeruginosa and therefore trigger resistance.

Evaluation of citrus pectin capped copper sulfide nanoparticles against Candidiasis causing Candida biofilms.

The incidence of candidiasis has significantly increased globally in recent decades, and it is a significant source of morbidity and mortality, particularly in critically ill patients. Candida sp. ability to generate biofilms is one of its primary pathogenic traits. Drug-resistant strains have led to clinical failures of traditional antifungals, necessitating the development of a more modern therapy that can inhibit biofilm formation and enhance Candida sp. sensitivity to the immune system. The present study reports the anticandidal potential of pectin-capped copper sulfide nanoparticles (pCuS NPs) against Candida albicans. The pCuS NPs inhibit C. albicans growth at a minimum inhibitory concentration (MIC) of 31.25 µM and exhibit antifungal action by compromising membrane integrity and overproducing reactive oxygen species. The pCuS NPs, at their biofilm inhibitory concentration (BIC) of 15.63 µM, effectively inhibited C. albicans cells adhering to the glass slides, confirmed by light microscopy and scanning electron microscopy. Phase contrast microscopy pictures revealed that NPs controlled the morphological transitions between the yeast and hyphal forms by limiting conditions that led to filamentation and reducing hyphal extension. In addition, C. albicans showed reduced exopolysaccharide (EPS) production and exhibited less cell surface hydrophobicity (CSH) after pCuS NPs treatment. The findings suggest that pCuS NPs may be able to inhibit the emergence of virulence traits that lead to the formation of biofilms, such as EPS, CSH, and hyphal morphogenesis. The results raise the possibility of developing NPs-based therapies for C. albicans infections associated with biofilms.

In vitro anticancer and antibacterial performance of biosynthesized Ag and Ce co-doped ZnO NPs.

The great potential of zinc oxide nanoparticles (ZnO NPs) for biomedical applications is attributed to their physicochemical properties. In this work, pure and Ag and Ce dual-doped ZnO NPs were synthesized through a facile and green route to examine their cytotoxicity in breast cancer and normal cells. The initial preparation of dual-doped nanoparticles was completed by the usage of taranjabin. The synthesis of Ag and Ce dual-doped ZnO NPs was started with preparing the Ce:Ag ratios of 1:1, 1:2, and 1:4. The cytotoxicity effects of synthesized nanoparticles against breast normal cells (MCF-10A) and breast cancer cells (MDA-MB-231) were examined. The hexagonal structure of synthesized nanoparticles was observed through the results of X-ray diffraction (XRD). Scanning electron microscopy (SEM) images exhibited the spherical shape and smooth surfaces of prepared particles along with the homogeneous distribution of Ag and Ce in ZnO with high-quality lattice fringes without any distortions. According to the cytotoxic results, the effects of Ag/Ce dual-doped ZnO NPs on breast cancer (MDA-MB-231) cells were significantly more than of pure ZnO NPs, while dual-doped and pure nanoparticles remained indifferent towards breast normal (MCF-10A) cells. In addition, we investigated the antimicrobial activity against harmful bacteria.

Photocatalytic and biological activities of green synthesized SnO2 nanoparticles using Chlorella vulgaris.

AIMS: To produce tin oxide (SnO2 ) nanoparticles (NP) with microalga for use in azo dye-polluted wastewater treatment and to optimize the conditions to synthesize as small NPs as possible. METHODS AND RESULTS: The green microalga Chlorella vulgaris mediated NPs were synthesized after an optimization process utilizing the statistical response surface methodology (RSM). The optimized synthesis conditions were 200 W microwave power, 0.5 mM SnCl2 concentration and 200°C calcination temperature. Methyl orange (MO) was studied for its photocatalytic degradation with UV. Antibacterial activity against four pathogenic bacteria was studied using the well diffusion method. Cytotoxicity was measured using the MMT assay with lung cancer cell line A549, and antioxidant activity using DPPH radical scavenging. Following the optimization of their production, the produced crystalline SnO2 NPs were on average 32.2 nm (by XRD) with a hydrodynamic size of 52.5 nm (by LDS). Photocatalytic degradation of MO under UV was nearly complete (94% removal) after 90 min and the particles could be reused for 5 cycles retaining 80% activity. The particles had antibacterial activity towards all five tested bacterial pathogens with the minimum inhibitory concentrations ranging from 22 to 36 µg/ml. The minimum bactericidal NP concentration varied between 83 and 136 µg/ml. Antioxidant activity was concentration dependent. A cytotoxicity was determined towards A549 cells with an LD50 of 188 µg/ml after 24 h of incubation, a concentration that is much higher than the active concentration for dye removal ranging from 22 to 36 µg/ml. CONCLUSIONS: After optimization, SnO2 nanoparticles produced with C. vulgaris displayed high photocatalytic activity at concentrations below their antibacterial and cytotoxic activities. SIGNIFICANCE AND IMPACT OF THE STUDY: The SnO2 nanoparticles produced with the help of microalgae are suitable for the removal of MO dye from wastewater. Further applications of this green technology can be expected.

Spirulina platensis mediated biosynthesis of Cuo Nps and photocatalytic degradation of toxic azo dye Congo red and kinetic studies.

The current research is designed to synthesis Copper oxide nanoparticles (CuO NPs) using Cyanobacterium in greener way. The NPs were synthesized using Spirulina platensis. The method is adopted for the less toxic, less cost and environment friendly method. The synthesized CuO NPs are capped and stabilized by the natural substance of S. platensis including flavonoids, phenolic and acid groups of the microorganism which was confirmed by the GC-MS analysis. Majorly, beta-ionone, p-cumic aldehyde, phytol compounds are identified by GC-MS and it may also involve in the preparation of NPs. Further, the characterization has been carried out using UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction, Scanning electron microscope (SEM), transmission electron microscope (TEM). All the analytical techniques are confirmed the formation of NPs. The formed NPs are showed significant peaks in XRD analysis which further compared with literature. Functional group analysis showed -OH group compounds in extract and it might involve in the formation of NPs. The photo catalytic activity of CuO NPs was showed significant photo degradation of Congo red (CR) dye. The consideration of intense peak, the size of CuO NPs was calculated and found to be 15.2 nm with spherical shape as resulted in morphological identification. The results are showed good photocatalytic activity, since the peak appeared at 230 and 495 nm corresponding to the benzene and azo group of Congo Red were gradually decreased with increase of time. The reaction was found to have nature of pseudo first order reaction. The rate constant was calculated and was found to be - k = 0.3459, which indicates the Congo red degradation was 0.3459 per minute. This study will be a base for budding researchers for their isolation of S. platensis active compounds and with the help of secondary metabolites (active compounds) CuO NPs were synthesized which further acted has degradation agent against Congo red.

A review on biogenic synthesis of metal nanoparticles using marine algae and its applications.

Marine algae have long been explored as food, feed, additives, drugs, and pesticides, yet now the framework is moving towards the algae mediated green synthesis of nanoparticles (NPs). This work is expanding step by step, like algae, are a rich origin of natural compounds. Recently, algae capped and stabilized NPs have picked up far and wide consideration as a less toxic, easy handling, cost effective, eco-friendly, usage in several science fields in nano size, safer to use, and greener method. The natural substance from algae acts as capping or reducing and stabilizing agent in the metal salts to metal, metal oxide, or bimetallic NPs conversion. The NPs using algae could either be intracellular or extracellular relying upon the area of NPs. Among the different scope of algae, reviews are explored in the previous report, still, different NPs using algae and their characterization, mechanism of activity is yet to be summarized. Because of the biocompatibility, good and remarkable physicochemical properties of NPs, the algal biosynthesized NPs have additionally been read for their biomedical applications, which include antibacterial, antioxidant, free radical scavenging, antifungal, anticancer, and biocompatibility properties. In this survey, the reasoning behind the algae mediated biosynthesis of various NPs from different algae origin have been explored. Besides, a piece of knowledge into the component of biosynthesis of NPs from marine algae and their biomedical applications has been summarized.

L-Asparaginase activity analysis, ansZ gene identification and anticancer activity of a new Bacillus subtilis isolated from sponges of the Red Sea.

This study describes the isolation of various marine bacteriafrom sponges collected from the Red Sea (Saudi Arabia) andL-asparaginase (anti-cancer enzyme) production from bacterialisolates. The 16S rDNA based phylogenetic analysis revealed thatthe isolate WSA3 was a Bacillus subtilis. Its partial-length genesequence was submitted to GenBank under the accession numberMK072695. The new B. subtilis strain harbored the exact size(1128 bp) of the new L-asparaginase (ansZ) gene as confirmedby PCR and in gel visualization, which was submitted to the NCBIdatabase (accession number MN566442). The molecular weightof partially purified L-asparaginase was determined as 45 kDa bySDS-PAGE. In addition, the enzyme L-asparaginase did not showglutaminase activity which is very important from a medical pointof view. Moreover, 100 µg/mL of the partially purified B. subtilis Lasparaginaseshowed promising anti-cancer activities when testedagainst three cancer cell lines (HCT-116, MCF-7, and HepG2).

Biological activities of the red algae Galaxaura rugosa and Liagora hawaiiana butters.

The biological activities; antimicrobial, antioxidant and anticancer, of the red algae Galaxaura rugosa and Liagora hawaiiana were determined. The total ethanol, lipoidal matters, chloroform, n-butanol, aqueous extracts and powder of both algae showed and bacterial and antifungal activities. However, the chloroform extract of Galaxaura rugosa showed antibacterial activity against Klebsiella pneumoniae (24 mm, 0.15 mg/ml) higher than gentamycin (23 mm, 0.49 mg/ml). Moreover, the total ethanol, lipoidal matter and chloroform extracts showed antifungal activity (21, 22 and 25 mm, 1.25, 0.312 and 0.156 mg/ml) similar to the antibiotic Ketoconazole activity (23, 24 and 27 mm, 1.25, 0.312 and 0.156 mg/ml) against Aspergillus fumigatus, A. niger and Candida trobicalis, respectively. A good antioxidant activity (80.96%, IC50 = 27.8 µg/ml) was provided by Galaxaura rugosa. The anticancer activity results revealed that the lipoidal matters of Galaxaura rugosa and Liagora hawaiiana possessed antitumor activity (IC50 = 15 ±â€¯1.7 and 21.2 ±â€¯1.6, respectively) against lung carcinoma (A-549) better than vinblastine sulfate (IC50 = 24.6 ±â€¯0.7). Although, the lipoidal matters of Galaxaura rugosa and Liagora hawaiiana antitumor activity against cervical carcinoma (HeLa) and intestinal carcinoma (CACO-2) (IC50 = 10.2 ±â€¯0.6 and 12.2 ±â€¯0.6, respectively) preferable than vinblastine sulfate (IC50 = 59.7 ±â€¯2.1 and 30.3 ±â€¯1.4, respectively).

Antimicrobial, antioxidant and anticancer activities of Laurencia catarinensis, Laurencia majuscula and Padina pavonica extracts.

The antimicrobial, antioxidant, and anticancer activities of ethanolic extract of Laurencia catarinensis, L. majuscula and Padina pavonica were determined. The highest antibacterial activity; 23.40 ±â€¯0.58 mm (00.98 µg/ml) and 22.60 ±â€¯2.10 mm (03.90 µg/ml) were obtained against Klebsiella pneumonia by Laurencia catarinensis and Padina pavonica, respectively. However, Padina pavonica showed excellent antibacterial activity against Bacillus subtilis (21.7 ±â€¯1.5 mm; 1.95 µg/ml), Staphylococcus aureus (21.7 ±â€¯0.58 mm; 1.95 µg/ml), Streptococcus pyogenes (20.7 ±â€¯1.2 mm; 1.95 µg/ml) and Acinetobacter baumannii (20.1 ±â€¯1.2 mm; 3.9 µg/ml). Moreover, the highest antifungal activity; 24.7 ±â€¯2.0 mm (0.98 µg/ml), 23.7 ±â€¯1.5 mm (0.98 µg/ml), 23.6 ±â€¯1.5 mm (0.98 µg/ml) was obtained by Padina pavonica against Candida tropicalis, C. albicans and Aspergillus fumigatus, respectively. The algal extracts showed DPPH radical scavenging activity in a concentration-dependent manner with maximum scavenging activity (77.6%, IC50 = 5.59 µg/ml and 77.07%, IC50 = 14.3 µg/ml) was provided by Padina pavonica and Laurenica majuscula, respectively. The in vitro antitumor activity revealed that the IC50 values of Padina pavonica were 58.9, 115.0, 54.5, 59.0, 101.0, 101.0, and 97.6 µg/ml; Laurencia catarinensis were 55.2, 96.8, 104.0, 78.7, 117.0, 217.0, 169.0 µg/ml; and Laurencia. majuscula were 115.0, 221.0, 225.0, 200.0, 338.0, 242.0, and 189.0 µg/ml; respectively against A-549 (Lung carcinoma), Caco-2 (Intestinal carcinoma), HCT-116 (Colon carcinoma), Hela (Cervical carcinoma), HEp-2 (Larynx carcinoma), HepG-2 (Hepatocellular carcinoma), and MCF-7 (Breast carcinoma) cell lines.

Isolation, identification and anti-candidal activity of filamentous fungi from Saudi Arabia soil.

Ten fungal strains; namely, Penicillium melinii, Petriella setifera, Aspergillus pseudo-niger, Alternaria chlamydospora, Pythium nayoroense, Phoma glomerata, Mucor ramosissimus, Mucor racemosus, Fusarium chlamydosporum and Rhizopus azygosporus were isolated from soil. The extra- and intra-cellular extracts of the fungal strains grown on malt extract and yeast-extract sucrose media were screened for their anticandidal activity against different clinically-isolated Candida species. Most of the fungal extracts showed activity against different Candida species. However, the fungal strains grew on malt extract showed greater activities than those grew on yeast extract sucrose media. The activity of the intracellular was higher than the extracellular metabolites. All fungal extracts (extra and intra) were similar in chemical constituent; they contained carbohydrates and/or glycosides, unsaturated sterols and/or triterpens, tannins and traces of coumarins. Alkaloids, flavonoids, saponins, anthraquinones and cardenolides were no detected. The intra-cellular extracts contained more compounds than the extra-cellular extracts.

Plant mediated biosynthesis of Mn3O4 nanostructures and their biomedical applications.

Nanomaterials have drawn significant attention for their biomedical and pharmaceutical applications. In the present study, manganese tetra oxide (Mn3O4) nanoparticles were prepared greenly, and their physicochemical properties were studied. Taxus baccata acetone extract was used as a safely novel precursor for reducing and stabilizing nanoparticles. The synthesized nanoparticles were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Brunauer-Emmett-Teller (BET), and Barrett-Joyner-Halenda (BJH) and X-ray diffraction (XRD). The cytotoxicity of Mn3O4 (hausmannite) nanostructures was evaluated against murine macrophage cell line J774-A1 and U87 glioblastoma cancer cells for approximately 72 h. Spherical Mn3O4 nanoparticles with tetragonal spinel structures demonstrated minimal toxicity against normal body cells with CC50 around 876.38 µg mL-1. Moreover, Mn3O4 nanoparticles as well as the combination of antimoniate meglumine and Mn3O4 nanoparticles exhibited maximum mortality in Leishmania major. The synthesized nanominerals displayed a significant inhibitory effect against glioblastoma cancer cells at 100 µg mL-1. The selective cytotoxicity of Mn3O4 nanoparticles indicates that these biogenic agents can be employed simultaneously for diagnostic and therapeutic applications in medical applications.

Structural, optical, morphological, sun-light driven photocatalytic and antimicrobial investigations of Ag2S and Cu/Ag2S nanoparticles.

This study focusses on the preparation of silver sulphide (Ag2S) and Cu-doped Ag2S (Cu/Ag2S) nanoparticles (NPs) by sol-gel method and demonstrated their photocatalytic and antibacterial applications. The X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) analysis demonstrated that the prepared NPs are effectively crystallized in the polycrystalline single-phase monoclinic geometry of Ag2S. The optical bandgap is significantly reduced, and for both the sample the average grain size is observed to have narrowed from 42 nm to 23 nm. Both NPs were confirmed to be spherical nature as observed by scanning electron microscopy (SEM), and the energy dispersive X-ray (EDX) spectroscopy analysis validated the presence of all necessary components at the expected concentrations in the obtained samples. Under the irradiation of sunshine, the photocatalytic properties of each sample were investigated for their ability to facilitate the photodegradation of a hazardous methylene blue (MB) dye in an aqueous solution. Cu/Ag2S sample possesses a profound photocatalytic reaction for the destruction of MB dye. Furthermore, the Cu-doped Ag2S NPs suppress the proliferation of Staphylococcus aureus and Escherichia coli. In comparison to pure Ag2S NPs, Cu/Ag2S showed enhanced antibacterial activity against both the bacteria. Current study suggests that the Cu doped Ag2S NPs could be a promising material for wastewater treatment and antimicrobial agents.

Optimized synthesis of silver nanoparticles using the marine fungus Aspergillus terreus and its application against resistant nosocomial pathogens.

The prevalence of bacterial infections in hospitals is rising, endangering currently accessible, efficient medical treatments and increasing demand for novel medications. Metal nanoparticles (NPs) are showing promise as materials for the development of treatments and preventative measures. This study investigated the potential of the fungus Aspergillus terreus to produce silver nanoparticles (AgNPs) as a means of creating green technology to synthesize NPs. The synthesis parameters were optimized using the central composite design (CCD). The formation of AgNPs by fungal biomass was confirmed by absorption spectroscopy, FTIR, powder XRD, scanning electron microscopy, and transmission electron microscopy. The antibacterial properties of the AgNPs were tested against three nosocomial drug-sensitive bacterial strains and their drug-resistant variants, vancomycin-resistant Enterococcus faecalis, and the multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii. The prepared AgNPs demonstrated good efficacies against the pathogens studied, and they merit further investigation to find treatments for infections caused by drug-resistant nosocomial pathogens.

Plant extract-mediated synthesis Cobalt doping in zinc oxide nanoparticles and their in vitro cytotoxicity and antibacterial performance.

In this research, zinc oxide (ZnO) nanoparticles doped with different percentages of produced cobalt using the green synthesis method. ZnO nanoparticles showed good cellular and microbial toxicity due to their high surface-to-volume ratio. Adding cobalt metal to the nanostructure can lead to the appearance of a new feature. To investigate the effect of adding cobalt metal, synthesized ZnO nanoparticles containing 3 and 6% cobalt were synthesized using plant extract. The resulting nanostructures were characterized by a Raman spectroscopy, UV-Visible spectrometer, X-ray diffraction, and Field emission scanning electron microscopy. Ultimately, the synthesized samples' cytotoxicity and antimicrobial tests were performed. XRD confirmed the formation of a hexagonal wurtzite ZnO structure. XRD and electron imaging showed that doping resulted in a decrease in average crystal size. The results showed that with cobalt doping, the particle size decreased slightly. The cytotoxicity and antimicrobial effects results showed that in all three studies, cobalt doping leads to an increase in the toxicity of this nanostructure compared to non-doped nanoparticles.

Optimized synthesis of mono and bimetallic nanoparticles mediated by unicellular algal (diatom) and its efficiency to degrade azo dyes for wastewater treatment.

The silver/palladium nanoparticles (Ag/Pd NPs) were efficiently absorb UV-Visible light and reveal greater photocatalytic activity as compared to monometallic NPs. The aim of this study is photodegradation of the industrial azo dye using bimetallic Ag/Pd NPs and monometallic Ag NPs in presence of UV light for wastewater treatment. Bacillariophyceae (diatom) algae extract was utilized for the green synthesized Ag and Ag/Pd NPs. Biosynthesized nanoparticles were characterized by various useful characterization techniques viz. UV-Vis, FT-IR, SEM, TEM, and XRD. The crystallite size is found to be ∼23 nm and ∼56 nm for Ag NPs and Ag/Pd NPs, respectively, which is same as results obtained from TEM analysis, as the particle size and shape were analyzed as ∼27 and ∼56 nm, with a spherical geometry. The NPs was used to develop the optimization parameters for dye degradation such as time, temperature, and NP concentrations. A total 15 runs were considered for the study and procured by statistical software. Response surface methodology technique was implied and Box-Behnken design (BBD) design was built into the workflow. The results of the present study manifested a good connection between experimental and predicted values (R2 = 0.9838). Therefore, present study promises that the prepared NPs possess excellent photocatalytic activity against harmful dyes.

Unraveling the potential of pesticide-tolerant Pseudomonas sp. augmenting biological and physiological attributes of Vigna radiata (L.) under pesticide stress.

In the agricultural domain, chemical pesticides are repetitively and harshly used to kill harmful pests, but they often pose a serious threat to microbial diversity, soil fertility and agricultural output. To deal with these problems, pesticide-tolerant plant growth promoting (PGP) rhizobacterial strains are often used to combat pesticidal toxicity. Here, Pseudomonas sp. PGR-11 (accession no. OM348534), recovered from a Vigna radiata (L.) rhizosphere, produced various growth regulating (GR) substances, including indole-3-acetic acid (IAA; 82.5 ± 9.2 µg mL-1), enzyme 1-aminocyclopropane 1-carboxylate (ACC) deaminase (µM α-ketobutyrate mg-1 protein h-1), siderophores and ammonia. Strain PGR-11 grew well when cultured in growth medium with added metalaxyl (MTXL; 1200 µg mL-1), carbendazim (CBZM; 800 µg mL-1) and tebuconazole (TBZL; 1600 µg mL-1). Pseudomonas sp. synthesized PGP substances even in the presence of increasing doses of pesticides. The phytotoxicity of the tested pesticides was assessed both in vitro and under pot-house conditions using a Vigna radiata (L.) crop. Increasing concentrations of chemical pesticides negatively impacted the growth, physiological and biochemical features. However, pesticide-tolerant Pseudomonas sp. relieved the toxicity and improved the biological attributes of the plant. Bio-inoculated plants showed significant enhancement in germination attributes, dry biomass, symbiotic features and yield features when compared to un-inoculated ones. Furthermore, with 100 µg metalaxyl kg-1 soil, strain PGR-11 increased the chl-a, chl-b, total chlorophyll, carotenoids, SPAD index, photosystem efficiency (Fv/Fm), PSII quantum yield (FPSII), photochemical quenching (qP) and non-photochemical quenching (NpQ) content by 12, 19, 16, 27, 34, 41, 26, 29 and 33%, respectively, over un-inoculated but pesticide-treated plants. Additionally, inoculation of Pseudomonas sp. with 100 µg tebuconazole kg-1 soil caused a significant (p ≤ 0.05) enhancement in transpiration rate (E), stomatal conductance (g s), photosynthetic rate (P N), vapor pressure deficit (kPa) and internal CO2 concentration (C i) of 19, 26, 23, 28 and 34%, respectively. Conclusively, the power to tolerate abnormally high pesticide concentration, the capacity to produce/secrete PGP substances even in a pesticide-stressed medium and the potential for improving/increasing the growth and physiology of plants by pesticide detoxification makes Pseudomonas sp. PGR-11 a fascinating choice for augmenting the productivity of V. radiata (L.) even in pesticide-stressed soils. The current findings will be helpful for exploring pesticide-tolerant ACC-deaminase-positive microbial strains as gifted entities for the environmental bioremediation of pesticides.

Bioremediation of ossein effluents using the filamentous marine cyanobacterium Cylindrospermum stagnale.

Wastewater containg proteinaceous ossein effluents are problematic to be treated. We studied the possibility to treat ossein effluents with the marine cyanobacterium strain Cylindrospermum stagnale. After optimizing the culture conditions of the bacterium, three different types of ossein effluents were tested: dicalcium phosphate (DCP), high total dissolved solids (HTDS) and low total dissolved (LTDS). The effluents were diluted with sea water at the following ratios 1:1, 2:1 and 3:2. The optimum operating conditions were at 3000 lux light intensity and 37 °C temperature. The highest degradation of ossein effluens by C. stagnale was attained for a dilution ratio of 1:1. However, less diluted ossein effluents reduced the growth of C. stagnale drastically. The degradation was shown by measuring the chlorophyll a content and the dry weight of bacterial cells during a seven-day incubation period degradation. Fourier Transform Infrared Spectroscopy (FT-IR) analysis verified the degradation showing the presence of the degradation products of ossein (i.e. calcium carbonate and calcite) in the culture medium. Lipid composition in fatty acids appeared to be suitable for biofuel production. The results showed that the marine cyanobacterium C. stagnale can be used to treat ossein effluents, and at the same time, to produce biofuel in a sustainable way.

Green synthesis of silver nanoparticles using Citrus limon peels and evaluation of their antibacterial and cytotoxic properties.

The present work aimed to synthesis silver nanoparticles (AgNPs) using biological waste products Citrus limon peels, its characterization, antimicrobial activities and the cytotoxic effect of the synthesized green AgNPs. Characterization of the prepared AgNPs showed the formation of spherical, and few agglomerated AgNPs forms as measured by UV-visible spectrophotometer. The average size of the prepared AgNPs was 59.74 nm as measured by DLS technique. The spectrum of the synthesized AgNPs was observed at 3 KeV using the EDX. On the other hand, FTIR analysis of the green synthesized AgNPs showed the presence of alcohols, phenolics, mono-substituted alkynes, aliphatic primary amines, sodium salt, amino acid, or SiOH alcohol groups. The antimicrobial studies of the formed AgNPs showed positive activity against most of the studied human pathogenic bacteria with varying degrees. Finally, the evaluation of the cytotoxic effect of the green synthesized AgNPs were done using two types of cell lines, human breast cancer cell line (MCF-7) and human colon carcinoma cell line (HCT-116). The results revealed the concentration has a direct correlation with cell viability. The 50% inhibitory concentration (IC50) of MCF-7 cell line was in of 23.5 ± 0.97 µL/100 µL, whereas the HCT-116 cell line was in 37.48 ± 5.93 µL/100 µL.