Studies on the antimicrobial effect of corn steep liquor on some diarrhoea causing organisms

Abstract

The antimicrobial effect of Corn Steep Liquor (CSL) was investigated over a five day period. The pH and titrable acidity of the liquor were determined, while the antimicrobial effect on some diarrhoea causing organisms such as Escherichia coli, Salmonella enteriditis, Staphylococcus aureus and Vibrio parahaemolyticus was also determined. Using well diffusion method, 0.1 ml (100 μl) of the liquor effectively inhibited the growth of the test organisms with zones of inhibition ranging from 4.00 ± 0.28 to 20.20 ± 0.14 mm. The zones of inhibition increased with increasing number of days of fermentation of the filtrate on which is the CSL. However, there was no significant difference (P>0.05) in the antimicrobial properties of the liquor on day 3 and 4 for S. enteriditis, S. aureus and V. parahaemolyticus. The zone of inhibition on day 5 was significantly different (P<0.05) from all other days except in S. enteriditis whose zone of inhibition was not significantly different from day 4 and 5. The degree of inhibition was highest in E. coli (20.20 ± 0.14 mm), followed by V. paraheamolyticus (18.50 ± 2.12mm); while S. enteriditis showed the minimum degree of inhibition to the CSL (13.20 ± 0.28 mm. The total microbial count and the titrable acidity of the liquor increased with increasing number of days and reached a peak on day 4 (355.60 ± 21.07 cfu/ml and 23.25 ± 2.05%, respectively). The pH however decreased with number of days. The result suggests that corn steep liquor which is considered a waste inhibits the growth of some diarrhoeic microbes especially by day four of fermentation.

Keywords: Anti-microbials, diarrhoea, pH, titrable acidity

African Journal of Biotechnology, Vol. 13(2), pp. 332-335, 8 January, 2014