Catfish seed production in the incubator is usually infected by microbes. Public health concern and the resistance of microbes to synthetic antibiotics have occasioned the need to explore alternative natural-based antimicrobial agent for more eco-friendly and responsible aquaculture practice. This study therefore investigated the antimicrobial properties of aqueous extracts from plant samples on isolates from catfish (Clarias gariepinus) incubators. Microbes were aseptically isolated from the mid-point of the base of the catfish incubator on the third day of post-spawning operation. Using standard laboratory methods, the microbes were identified and assessed for Zone of Inhibition (ZI), Minimum Microbicidal Concentration (MMC) and Minimum Inhibitory Concentration (MIC) following application of aqueous extracts of Senna alata, Mitracarpus scaber and physalis peruviana. Data obtained from the laboratory observations were subjected to analysis of variance, tested at 95% confidence limit using IBM SPSS 22® statistical package.
The results of the analysis (Table 1) showed that the ZI was significantly highest (p < 0.05) in Physalis peruviana extract and lowest significantly in Mitracarpus scaber extract. Exposure concentration of 100 mg/l of the extracts resulted into a significant increase (p < 0.05) in the ZI.
It can be concluded that Physalis peruviana showed high potency against microbes isolated from the catfish incubator among the three extracts, at a concentration of 100mg/ml.