Aspergillus tamarii mediated green synthesis of magnetic chitosan beads for sustainable remediation of wastewater contaminants.

The release of different hazardous substances into the water bodies during the industrial and textile processing stages is a serious problem in recent decades. This study focuses on the potentiality of Fe3O4-NPs-based polymer in sustainable bioremediation of toxic substances from contaminated water. The biosynthesis of Fe3O4-NPs by A. tamarii was performed for the first time. The effect of different independent variables on the Fe3O4-NPs production were optimized using Plackett-Burman design and central composite design (CCD) of Response Surface Methodology. The optimum Fe3O4-NPs production was determined using incubation period (24 h), temperature (30 °C), pH (12), stirring speed (100 rpm) and stirring time (1 h). The incorporation of Fe3O4-NPs into chitosan beads was successfully performed using sol-gel method. The modified nanocomposite exhibited remarkable removal capability with improved stability and regeneration, compared to control beads. The optimal decolorization was 94.7% at 1.5 g/l after 90 min of treatment process. The reusability of biosorbent beads displayed 75.35% decolorization after the 7th cycle. The results showed a highly significant reduction of physico-chemical parameters (pH, TDS, TSS, COD, EC, and PO4) of contaminated wastewater. The sorption trials marked Fe3O4-NPs-based biopolymer as efficient and sustainable biosorbent for the elimination of hazardous toxic pollutants of wastewater in a high-speed rate.

Production of hydroxy marilone C as a bioactive compound fromStreptomyces badius.

Hydroxy marilone C is a bioactive metabolite produced from the culture broth of Streptomyces badius isolated from Egyptian soil. Hydroxy marilone C was purified and fractionated by a silica gel column with a gradient mobile phase dichloromethane (DCM):methanol then Sephadex LH-20 column using methanol as a mobile phase. It was subjected to many procedures such as infrared (IR), nuclear magnetic resonance (NMR), Mass spectroscopy (MS) and UV spectroscopy for elucidation of its structure. It was evaluated for antioxidant, cytotoxicity against human alveolar basal epithelial cell line (A-549) and human breast adenocarcinoma cell line (MCF-7) and antiviral activities; showed that the maximum antioxidant activity was 78.8% at 3 mg/ml after 90 min. and the IC50 value against DPPH radical found about 1.5 mg/ml after 60 min. Using MTT assay the effect of the pure compound on the proliferation of A-549 cells and MCF-7 cells was 443 µg/ml and 147.9 µg/ml, respectively, while for detection of antiviral activity using Madin-Darby canine kidney (MDCK) cells the maximum cytotoxicity was at 27.9% and IC50 was 128.1 µg/ml. The maximum concentration required for protecting 50% of the virus-infected cells against H1N1 viral cytopathogenicity (EC50) was 33.25% for 80 µg/ml. These results indicated that the hydroxy marilone C has potential antitumor and antiviral activities.

Production and characterization of antimicrobial active substance from Spirulina platensis.

BACKGROUND AND OBJECTIVES: The present work was carried out to investigate the ability of Spirulina platensis to produce antimicrobial substance against bacteria and fungi. MATERIALS AND METHODS: The cells of the cyanobacterium were subjected to different extractions and the purified antagonistic compound proved to be effective against broad spectrum of bacteria and fungi. The antagonistic compound was purified using thin layer chromatography. RESULTS: The results indicated that the IR spectrum showed bands at 1269 cm(-1), 1414 cm(-1) (C-O-C), 1643 cm(-1) (CO of amide),1563 cm(-1) (C = C) and broad band 3441 cm(-1) (of OH and NH)., (1)HNMR showed δ 0.8 (-CH3), δ 1.2 (-CH2), δ 4.2(-OH), δ 7.2(-NH), δ 7.4 and δ 7.7 (aromatic CH)., Mass spectrum showed molecular ion beak at m/z = 341 (abundance (0.03%). Also, the elemental analysis gave molecular formula,C15H18NO8. CONCLUSION: The purified antimicrobial compound produced by S. platensis was more active against Gram positive, Gram negative bacteria and unicellular fungi, C. albicans. The highest biological activity was recorded against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Aspergillus niger. The results of this investigation proved that cyanobacteria could be a good source for production of antimicrobial agents which could be effective when compared with contemporary antimicrobial compounds.