Fungi generate different metabolites some of which are intrinsically bioactive and could therefore serve as templates for drug development. In the current study, six endophytic fungi namely Aspergillus flavus, Aspergillus tubigenesis, Aspergillus oryzae, Penicillium oxalicum, Aspergillus niger and Aspergillus brasiliensis were isolated and identified from the medicinal plant, Silybum marianum. These endophytic fungi were identified through intra transcribed sequence (ITS) gene sequencing. The bioactive potentials of fungal extracts were investigated using several bioassays such as antibacterial activity by well-diffusion, MIC, MBC, anti-biofilm, antioxidant, and haemolysis. The Pseudomonas aeruginosa strain PAO1 was used to determine the antibiofilm activity. The ethyl acetate extract of Aspergillus flavus showed strong to moderate efficacy against Staphylococcus aureus, Escherichia coli, P. aeruginosa, and Bacillus spizizenii. Aspergillus flavus and Aspergillus brasiliensis exhibited significant antibiofilm activity with IC50 at 4.02 and 3.63 mg/ml while A. flavus exhibited maximum antioxidant activity of 50.8%. Based on, HPLC, LC-MS and NMR experiments kojic acid (1) and carbamic acid (methylene-4, 1-phenylene) bis-dimethyl ester (2) were identified from A. flavus. Kojic acid exhibited DPPH free radical scavenging activity with an IC50 value of 99.3 µg/ml and moderate activity against ovarian teratocarcinoma (CH1), colon carcinoma (SW480), and non-small cell lung cancer (A549) cell lines. These findings suggest that endophytic fungi are able produce promising bioactive compounds which deserve further investigation.
Photocatalysis appears to be an appealing approach for environmental remediation including pollutants degradation in water, air, and/or soil, due to the utilization of renewable and sustainable source of energy, i.e., solar energy. However, their broad applications remain lagging due to the challenges in pollutant degradation efficiency, large-scale catalyst production, and stability. In recent decades, massive efforts have been devoted to advance the photocatalysis technology for improved environmental remediation. In this review, the latest progress in this aspect is overviewed, particularly, the strategies for improved light sensitivity, charge separation, and hybrid approaches. We also emphasize the low efficiency and poor stability issues with the current photocatalytic systems. Finally, we provide future suggestions to further enhance the photocatalyst performance and lower its large-scale production cost. This review aims to provide valuable insights into the fundamental science and technical engineering of photocatalysis in environmental remediation.
Environmental Pollutants , Environmental Restoration and Remediation , Solar Energy , Technology , Soil , Catalysis
Endophytes are microorganisms residing within plant tissues. Bacterial endophytes are important sources for production of pharmaceutically important metabolites. Berberis lycium is an important medicinal plant and there exist no report regarding isolation and determination of bioactive potential of its bacterial endophytes. Therefore the present study was aimed to isolate and identify bacterial endophytes from Berberis lycium. The study resulted in isolation of 20 strains of bacterial endophytes. Based on their antibacterial activity three strains were identified as Bacillus cereus (LBL6), Bacillus thuringiensis (SBL3) and Bacillus anthracis (SBL4) on basis of 16SrRNA gene using universal primers. Crude ethyl acetate extracts of LBL6, SBL3 and SBL4 were further evaluated for antioxidant and antifungal activities. Moderate antioxidant activity (56 %) at a concentration of 1000 µg/mL was observed for LBL6 followed by 45 and 43 % activity by SBL4 and SBL3 respectively. Significant antifungal activity was observed against Aspergillus niger (60 %) and Aspergillus flavus (56 %) at concentration of 4 mg/mL of SBL3 and SBL4 respectively. GCMS analysis of extract (LBL6) exhibited presence of 12 bioactive secondary metabolites corresponding to antimicrobial, antifungal, antioxidant, antitumor and anticancer activities. In conclusion, present study highlighted the importance of Berberis lycium to host diverse bacterial endophytes of pharmaceutical importance.
