PROMOTING ACCESS TO AFRICAN RESEARCH

African Journal of Biotechnology

Log in or Register to get access to full text downloads.

Remember me or Register



In vitro antilisterial properties of crude aqueous and nhexane extracts of the husk of Cocos nucifera

TA Akinyele, DA Akinpelu, AL Okoh

Abstract


The in vitro antilisterial activities and time kill regimes of crude aqueous and n-hexane extracts of the husk fiber of Cocos nucifera were assessed. The aqueous extracts were active against 29 of the 37 test Listeria isolates while the n-hexane extracts were active against 30. The minimum inhibitory concentrations (MICs) of all the susceptible bacteria ranged between 0.6 and 2.5 mg/ml for the aqueous fraction and between 0.6 and 5.0 mg/ml for the n-hexane extract. The average log reduction in viable cell count in the time kill assay ranged between 0.32 Log10 and 3.2 Log10 cfu/ml after 4 h of interaction, and between 2.6 Log10 and 4.8 Log10 cfu/ml after 8 h interaction in 1 × MIC and 2 × MIC (aqueous extract); and between 2.8 Log10 and 4.8 Log10 cfu/ml after 4 h of interaction, and 3.5 Log10 to 6.2 Log10 cfu/ml after 8 h interaction in 1 × MIC and 2 × MIC for the n-hexane extract. The extract was bactericidal against one of the test bacteria at 1 × MIC and against three of the test bacteria at 2 × MIC for the 8 h interaction period for the aqueous extract, while for the n-Hexane fraction; the extract was bactericidal against all the five test bacteria at both MICs after the 8 h interaction period. We suggested that the crude aqueous and n-hexane extracts of the husk of C. nucifera could be bacteriostatic or bactericidal depending on the time of exposure and concentration.

Key words: Cocos nucifera, n-hexane extract, aqueous extract, minimum inhibitory concentration, time-kill.




http://dx.doi.org/10.5897/AJB11.330
AJOL African Journals Online