Antioxidant capacity of Pleurotus ostreatus (Jacq.) P. Kumm influenced by growth substrates.

Functional constituents are the main concern in food production and consumption. Because foods rich in functional constituents have antioxidant capacity and are important in keeping consumers healthy. Pleurotus ostreatus is among foods rich in functional constituents. However, its functional constituents are affected by various factors. This study compared the antioxidant capacity of P. ostreatus grown on different substrates: straws of tef (Trt1), barley (Trt2), and wheat (Trt3), husks of faba bean (Trt4), and field pea (Trt5), sawdust (Trt6), and the mixture of the above with 1:1 w/w (Trt7). Trt7 had significantly higher radical scavenging activity (RSA) (73.27%), vitamin C (10.61 mg/100 g), and vitamin D (4.92 mg/100 g) compared to other treatments. Whereas the lowest values of RSA (44.24%), vitamin C (5.39 mg/100 g), and vitamin D (1.21 mg/100 g) were found in Trt2. The results indicated that mixed substrate may be a good growth substrate for functionally beneficial P. ostreatus and could be a promising source of natural antioxidants.

Biosynthesis, characterisation and antimicrobial activity of zinc oxide and nickel doped zinc oxide nanoparticles using Euphorbia abyssinica bark extract.

Biosynthesis of metallic oxide nanoparticles is being used and preferred over physical and chemical methods of synthesis since it is simple, inexpensive, environmentally friendly, and green. The aim of this study was to synthesise ZnO and nickel doped ZnO nanoparticles using Euphorbia abyssinica bark extract for antimicrobial activity studies via agar disk diffusion method against some selected microbes. The synthesised nanoparticles were characterised using X-ray diffraction (XRD), ultraviolet-visible spectroscopy, and Fourier transform infrared spectroscopy. The study results revealed that the biosynthesised nanoparticles had good crystalline nature, with crystal sizes in the range of nanoparticles and structures of hexagonal wurtzite. Both undoped ZnO and nickel doped ZnO nanoparticles demonstrated antibacterial and antifungal activity against four bacterial strains and two fungal genus. Generally, nickel doped ZnO NPs were found to possess more antimicrobial activities than undoped ZnO NPs. Specially, 4% and 5% nickel doped ZnO NPs showed significantly enhanced activity against Enterococcus faecalis, Staphylococcus aureus, Aspergillus and Fusarium.

Survey and Antimicrobial Activity Study of Ethnomedicinal Plants in Selected Districts of North Shewa Zone, Oromia, Ethiopia.

BACKGROUND: The emergency of multidrug resistance due to the global burden of infectious diseases and drug misuse leads to an urgent identification of new medicines from medicinal plants. The study was designed to perform the documentation of ethno-medicinal plants usage, extraction, phytochemical screening and antimicrobial activities of the herbal extracts. METHODS: A cross-sectional study design was conducted in this study. Maceration of plant extraction, phytochemical screening and disc diffusion method for antimicrobial activity tests were employed. RESULTS: The results of the study indicated that Euphorbiaceae, Lamiaceae and Sapindaceae plant families have commonly used for the treatment of infectious diseases in the study areas. The antimicrobial activity test results indicated that Ostegia integrifolia Benth which was extracted with chloroform solvent showed equivalent inhibition zone as compared to standard drug, gentamicin. All the extracts could be considered as broad spectrum, have strong inhibition against E. coli, K. pneumoniae, S. aureus, P. aeruginosa and C. albicans. All extracts against C. albicans were also revealed strong inhibition activity as compared to fungal standard drug, contamazole. CONCLUSION: Phytochemical screening showed the existence of secondary metabolites in the studied plants and thus, supports the traditional healers' claim of such plants use for the treatment of diseases. The study also concluded that chloroform extracts of all plants showed promising antimicrobial activities against K. pneumonia, and C. albicans. Therefore, further in vitro and vivo antimicrobial activity study of chloroform extracts against these bacterial and fungal strains were recommended. Moreover, isolation and structural elucidation of bioactive compounds from chloroform extracts were also recommended.