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Published on: July 31, 2019
A fermentation assay to evaluate the effectiveness of antimicrobial agents on gut microflora
S Shanmugavelu1, G Ruzickova, J Zrustova
1Avian Science Research Centre, Scottish Agricultural College, West Mains Rd, Edinburgh, EH9 3JG, UK.
Journal of Microbiological Methods
|April 25, 2006
Summary
This study developed a rapid in vitro assay measuring gas production to screen antimicrobial compounds against chicken gut bacteria. The method effectively tested essential oils and tannins, correlating fermentation inhibition with bactericidal effects for potential poultry feed additives.
Area of Science:
- Microbiology
- Animal Science
- Pharmacology
Background:
- Gastrointestinal microorganisms in chickens play a crucial role in nutrient metabolism and gut health.
- Assessing the antimicrobial activity of plant-derived compounds against these microbes is vital for developing effective feed additives.
- Existing methods for evaluating antimicrobial efficacy can be time-consuming and complex.
Purpose of the Study:
- To develop and optimize a rapid in vitro fermentation assay for screening the antimicrobial activity of plant secondary metabolites.
- To correlate gas production as a measure of fermentation with bacterial growth (absorbance).
- To determine the minimum inhibitory concentrations (MICs) of essential oils and tannins against specific chicken gut bacteria.
Main Methods:
- Optimization of a gas production assay using Clostridium perfringens and Lactobacillus fermentum.
- Antimicrobial testing of essential oils and condensed tannins against Clostridium perfringens.
- Determination of minimum inhibitory concentrations (MICs) for selected compounds.
- Application of the assay to evaluate the effects of dietary composition and enzyme supplementation on mixed gut microflora fermentation in vitro.
Main Results:
- The gas production assay effectively correlated with bacterial growth (absorbance) and was optimized for screening antimicrobial activity.
- Concentrations of essential oils and tannins that inhibited fermentation were found to be bactericidal against Clostridium perfringens.
- The assay demonstrated similar effects of penicillin-G on bacterial growth and fermentation, validating its use.
- Results from in vitro fermentation assays using mixed gut microflora showed good correlation with in vivo data for dietary treatments.
Conclusions:
- In vitro analysis of fermentative activity provides a rapid and reliable method for assessing the impact of bioactive compounds and feed composition on gut microflora.
- This assay serves as a valuable tool for pre-screening potential poultry feed additives before conducting extensive in vivo trials.
- The findings support the use of plant secondary metabolites and optimized feed composition for modulating chicken gut health.
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