บทคัดย่อ
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Abstract
The antimicrobial activity of mulberry (Morus alba L.) leaf extracts on bacterial soft rot cause by Erwinia carotovora subsp. carotovora (ATCC 15713) were studied. Fresh mulberry leaves were dried at 60°C for 12 h and later were processed to powder using 70 mesh size sieve. Extracts were obtained by extracting powder using distilled water into three extract concentrations i.e. 5%, (MP5), 7.5% (MP7.5), and 10% (w/v) (MP10). Antimicrobial activities of all extract concentrations were tested against Erwinia carotovora using the paper disc diffusion method on the Luria-Bertani agar, in comparison to those of a range of ampicillin concentrations including 3.125, 6.25 and 12.5 µg/ml, as well as only distilled water (designated as control). The study also investigated total phenolic content and quercetin content of the extracts. Experimental findings showed that the mulberry leaf extract (10g %, w/v) had reasonable antimicrobial activity against the Erwinia carotovora upto 5 days. The antimicrobial activities of the extracts are concentration dependent. These are attributed to contents of phenolic compounds mainly as quercetin in the mulberry leaf. Contents of total phenolic and quercetin in the mulberry powder extracts increased with higher concentrations of the extract.
Keywords : Antimicrobial activity, Erwinia carotovora subsp. carotovora (ATCC 15713),
Morus alba L., Mulberry leaf extract
