Biofiltration technology for the removal of toluene from polluted air using Streptomyces griseus

Biofiltration technology has been recognized as a promising biotechnology for treating the volatile organic compounds (VOCs) present in polluted air. This study aims to investigate the performance of a biofiltration system of Streptomyces griseus sp. DSM-40759 immobilized on activated carbon (PICA S23) towards the adsorption and degradation of toluene vapour as well as to regenerate the activated carbon in situ. The batch studies were performed using nutrient agar medium and basal salt medium (BSM) for microbial growth. Initially the pre-cultures were incubated at a temperature of 28°C on a rotary shaker at 150 rpm. After two days, the strain S. griseus DSM-40759 was immobilized on a known weight of activated carbon (12 g). The results of biofilter performance showed three different stages with a quick adsorption phase with approximately 95% of toluene removal after 70 min, a slow biotransformation phase by immobilized cells. In the later, the removal efficiency decreased significantly with the extension of time and reached 60% during this stage. Moreover, a final quick removal phase by the immobilized cells had an average removal efficiency of toluene around 95% after 500 min. The toluene degradation was found to be more than 84% after the second cycle and the biofilter was still capable of removing additional toluene. Thus, the results demonstrated the feasibility and reusability of a new biofilter system for toluene removal as well as extending the activated carbon's capacity and this could be a potential solution to reuse the activated carbon in industrial application

Enhanced production of streptomycin and hydrolytic enzymes by Streptomyces griseus strains using different types of organic solvents and detergent compounds

341-348Different organic solvents and detergents showed profound effects on the production of streptomycin (SM), amylases and proteases by Streptomyces griseus strains. The maximum SM production (1128 and 780 mg/L) was obtained using Streptomyces NRRL-strain when ethanol (1.0% v/v) and Tween-80 (0.1%v/v) were added to the medium. Production of amylases was also enhanced using the strain with the addition of benzene at decline phase, n-butanol at the trophophase and isopropanol at the idiophase with values, 10.66, 8.28 and 8.05 U/mL for -amylase (EC-3.2.1.1) and 6.28, 4.68 and 4.55 for -amylase (EC-3.2.1.2), respectively. While the use of other solvents and detergents reduced the production of amylase specially activities by S. griseus DSM-40759, characterized by higher productions of - and -amylases in different growth phases especially at the death phase. Worthily, proteases secretion was only induced to 1.02 U/mL at the idiophase by culturing DSM-strain with the addition of Triton X-100 and SDS to the fermentation medium. Moreover, the solvents shifted the pH values in the acidic range by the two strains at different phases compared to the control

PRODUCTION AND CHARACTERIZATION OF ECONOMICAL BACTERIAL CELLULOSE

The present study investigates the economical production of bacterial cellulose (BC) by Gluconacetobacter subsp. Xylinus (ATCC 10245) in 250 ml Erlenmeyer flasks cultivated under static conditions. The fermentation media used contained food industrial by-product liquors, such as black strap molasses solution and corn steep liquor (CSL), which represents some of the most economical carbon and nitrogen sources. However, because of the presence of undesirable components in molasses (such as coloring substances, heavy metals, and other compounds) that may act as inhibitors, and in order to eliminate them, crude molasses has been treated with an acid, as an attempt to increase BC productivity. The amount of BC produced using these carbon and nitrogen sources was determined and compared to that produced using previously reported fermentation media. The characterizations of the bacterial cellulose (BC) pellicles obtained using either conventional or by-product media were studied by thermal and spectral techniques and compared to those of plant-derived cellulose such as cotton linter, viscose pulp, and microcrystalline cellulose

Antiviral and Antioxidant Potential of Fungal Endophytes of Egyptian Medicinal Plants

This study aimed to explore the antioxidant potential and antiviral activity of endophytic fungi which were isolated from healthy living tissues of medicinal plants. Endophytic strains (29 different taxa) were isolated from 18 Egyptian medicinal plants collected from Saint Katherine Protectorate, Egypt. The fungal endophytes were identified based on morphological characters. All isolates were identified as ascomycetes, except two Zygomycetes strains (Absidia corymbifera and Mucor fuscus). Isolated endophytes were cultivated on potato dextrose media. The fungal metabolites were extracted by ethyl acetate and examined for their biological activities. Among 99 total extracts, only Chaetomium globosum, which was isolated from Adiantum capillus, showed a promising DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging activity (99% at 100 µg/mL). Fifteen extracts prohibited the reproduction of HSV-2 virus. On the other hand, the reproduction of VSV-virus was inhibited by sixteen endophytic extracts. The promising anti-(HSV-2 and VSV) extract of endophytic Pleospora tarda strain; that was originally isolated from the medicinal plant Ephedra aphylla, showed viral inhibitory activity of 40.7% and 15.2%, respectively. Two compounds, for which antiviral activates could be attributed, were isolated and identified as alternariol and alternariol-(9)-methyl ether using different NMR techniques from P. tarda extract. For the first time, we report here the ability of the endophytic fungus P. tarda to produce alternariol and alternariol-(9)-methyl ether. The results indicate that the endophytic fungi from medicinal plants are promising sources of bioactive compounds

High Expression Level of Antioxidants and Pharmaceutical Bioactivities of Endophytic Fungus <i>Chaetomium Globosum</i> JN711454

<div><p>In order to maximize antioxidant activity of pharmaceutical bioactive endophytic fungus <i>Chaetomium globosum</i> JN711454 during fermentation process, designed fermentation experiments of culture media for three levels of eight culture factors were performed using Taguchi Orthogonal Array (OA) design with layout L18 (2¹x3⁷). The agitation and the potato extract were the most significant affecting factors and their interaction contributed significantly on fungus activity. The production of antioxidants was more favorable for static condition with 25 g potato extract/100 ml. The remaining factors had no strong impact when considered individually. The validation of statistically optimized medium indicated the improvement of antioxidant activity to the level of double fold with approximately overall 40% enhancement in activity. The extract of optimized medium was investigated for various pharmaceutical bioactivities; it revealed a moderate antimicrobial activity, strong anticancer activity against HepG-2, UACC62 cell lines, an antiviral activity against HSV-2 virus, and strong inhibitory activity to butyrylcholinesterase enzyme, one of neuro hydrolase enzymes that play a major role in development of Alzheimer's disease. As a result of applying statistical fermentation designs, the optimized conditions of endophytic fungus <i>C. globosum</i> JN711454 developed a cost-effective production medium by using inexpensive commercial potato extracts statically, which can lower energy requirement and could become an efficient, economic, and viable fermentation process for production of pharmaceutical secondary metabolites.</p></div

Applications of Plackett–Burman and Central Composite Design for the Optimization of Novel Brevundimonas diminuta KT277492 Chitinase Production, Investigation of its Antifungal Activity

ABSTRACT Biological control strategy which can damage chitin, a vital component of pathogenic fungi and arthropods promises a safe solution for many fungal problems. And it’s more favorable than chemicals which increase health risks and environmental problems. Thus, the chitinase producers appear potential candidates of biological control of pathogenic fungi. Brevundimonus diminuta KT277492 is a new isolate that has been isolated recently from Egyptian soil. Significant factors that affecting the chitinase enzyme production were studied and optimized using Plackett-Burman and Response Surface Methodology (RSM). As a result, maximum production of chitinase enzyme was 832.87 IUL-1, this result presented about 8.767-fold increase in the enzyme production. In the last phase of the study, partially purified chitinase enzyme obtained from B. diminuta KT277492 was tested against two pathogenic fungi and the results showed good inhibitory activity against A. alternata and F. solani with IZD of 31±0.25 and 25±0.91 mm respectively. Finally, obtained results indicated the value of optimization process and the optimized chitinase enzyme could be an excellent choice in application of food and biotechnology as a biofungicide. This reflects the necessity of studying the characteristics and kinetics of the enzyme in the forthcoming study