Effect of organic acids and ensiling of cattle dung on the growth of Clostridium perfringens

Abstract

Abstract The influence of organic acids at different pH values on the growth of Clostridium perfringens was examined: propionic acid was found to be the most inhibitory, followed by lactic, butyric and acetic acids. The inhibition of bacteria increased with decreasing pH and increasing concentration of organic acid at a given pH. C. perfringens was able to initiate growth at a pH as low as 4·6 in the absence of organic acids. The ensiling of cattle dung with wheat straw and sugarcane molasses had a detrimental effect on the growth of C. perfringens. When the above premix was inoculated with a mixture of Lactobacillus plantarum and Streptococcus faecalis, the pH of the wastelage after 20 days of fermentation at 37°C was 3·8 and C. perfringens was killed, but its number was also reduced considerably in a wastelage of pH 4·25, in which the lactic acid-producing bacteria had not been inoculated.