Submitted to: Food Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/2/2020
Publication Date: 1/6/2020
Citation: Jia, Z., Liu, Y., Hwang, C., Huang, L. 2020. Effect of combination of oxyrase and sodium thioglycolate on growth of Clostridium perfringens under aerobic incubation. Food Microbiology. 89:103413. https://doi.org/10.1016/j.fm.2020.103413.
Interpretive Summary: Clostridium perfringens is an anaerobic pathogen that can produce enterotoxins causing outbreaks of food poisoning. The study of growth of C. perfringens in foods must be conducted under oxygen-free conditions that require the use of expensive anaerobic systems. This kinetic study was conducted to evaluate the application of Oxyrase as an oxygen-scavenger to allow the observation of its growth under aerobic incubation. This study shows that the Oxyrase, when applied properly, may allow C. perfringens to grow without the need of using anaerobic incubation systems. The results of this study may simplify the experimental procedures for studying the growth of C. perfringens in foods.
Technical Abstract: Clostridium perfringens is a strictly anaerobic pathogen that requires absence of oxygen for its growth in laboratory experiments, which is usually attained by using an anaerobic chamber or anaerobic jars. However, it has been demonstrated that C. perfringens may survive for short periods of times due to its adaptive response to O2. Therefore, the objective of this study was to explore the application of Oxyrase (OX) and sodium thioglycolate (ST) as oxygen scavengers, used alone or in combination, for observation of the growth of C. perfringens under aerobic incubation. The growth of C. perfringens in Schaedler Anaerobe Agar containing different levels and combinations of OX and ST was observed at temperatures between 20 and 50°C under aerobic incubation. The kinetic parameters, including lag time, specific growth rate, and maximum cell concentrations in the stationary phase were determined. The results indicated that ST at concentrations of 0.025 and 0.05% (w/w), although allowing eventual growth of C. perfringens, prolonged its lag times, while OX at 1.5% decreased its growth rate. OX at 3% enhanced the growth of C. perfringens at temperatures between 30 and 50°C, while higher levels of OX were needed in the media to support the growth of C. perfringens during storage at 25°C (>6% OX ) and 20°C (>9% OX ). No significant difference was found in the kinetic parameters of C. perfringens incubated aerobically with OX and in an anaerobic chamber without OX. Therefore, OX at appropriate concentrations may allow the observation of the growth of C. perfringens under aerobic incubation conditions without the need of an anaerobic device.