IN VITRO DPPH RADICAL SCAVENGING AND ANTI-BACTERIAL ACTIVITY OF OMAN'S CYMBOPOGON

Objective: The objective of this work is to evaluate antioxidant and anti-microbial activity of methanolic extract of Omani Cymbopogan schoenanthus.Methods: Antibacterial activity of mehanolic extract of Cymbopogan was evaluated by agar well diffusion method along with positive controls (Streptomycin, tetracycline and chloramphenicol). Antioxidant activity of the mehanolic extract of C. schoenanthus was done by 1, 1-diphenyl-2picrylhydrazyl (DPPH) free radical scavenging assay.Results: The results indicate that the methanolic extract of C. schoenanthus is able to restrict the growth of organisms such E. coli, Klebsiella, Staphylococcus and Bacillus partially and it is not an effective antibacterial agent. In addition, the extract can scavenge the DPPH in vitro better than ascorbic acid (1 mg/ml).Conclusion: To the best of our knowledge this is the first report on Omani C. schoenanthus as an antibacterial and antioxidant agent. Characterization of active principle responsible for observed biological activities is ongoing in our laboratory.Keywords: Antibacterial, Antioxidant, Cymbopogon, Oman

Different salinity effects on the mass cultivation of spirulina (Arthrospira platensis) using urea as nitrogen source in Oman and Malaysia

Mother earth is facing multitude of problems such as desertification, diminishing cultivation land and malnutrition. One way to overcome these problems is through cultivation of Spirulina (A. platensis). This paper focused on the different effects of salinity and comparative climate patterns to the mass production of A. platensis in Oman and in Malaysia. With extremely contrasting environment, A. platensis has unique ability to grow in both tropical (Malaysia) and arid (Oman) outdoor conditions. Mass cultivation has been carried out at different salinity 5, 15, 25 and 35 ppt for 10 days with triplicates in both countries. The total volume of culture in each tank and land photobioreactor was maintained at 100 L and 50L respectively. In Oman, the highest optical density (ABS) was 1.691 ± 0.099 at 5 ppt significantly different and higher than 25 and 35 ppt (p 0.05). While in Malaysia, the highest optical density (ABS) recorded with Spirulina dry weight was collected from Spirulina culture treatment with 5 ppt, 0.974 ± 0.052 was not significantly different from other salinity treatments (p > 0.05) and the dry weight at 0.575 ± 0.032 g L -1 was significantly different to 25 and 35 ppt (p < 0.05). Highest average mean ± SE of pH in Oman and Malaysia were recorded with salinity treatment of 15 ppt, 10.60 ± 0.058 and 10.20 ± 0.037