Comparison of batch culture growth and fermentation of a poultry Veillonella isolate and selected Veillonella species grown in a defined medium

Abstract

The objective of this study was to develop a defined medium for quantitating nutritional requirements and fermentation products of a poultry cecal isolate of Veillonella and to compare these parameters with representative Veillonella species. The poultry isolate is one of 29 organisms from a continuous-flow culture that has been shown to be effective against Salmonella colonization in broilers. When the Veillonella species were grown in anaerobic batch culture, propionate and acetate were the only volatile fatty acids detected. Lactate was needed to provide energy for the growth of the Veillonella in the defined medium. The poultry isolate had significantly (p< 0.05) higher Y(lactate)(g of dry cell weight per mole of lactate utilized) and dry cell weight than the other Veillonella species when grown on amino acid supplemented defined media. Cultures of the Veillonella species in the defined medium grown with supplemented amino acids aspartate, threonine, arginine, and serine indicated that these amino acids were metabolized to acetate and propionate. Amino acid analysis on media inoculated with either V. atypica or the poultry isolate also indicated that these organisms may have different amino acid preferences. For nearly all of the amino acid supplemented media combinations the poultry isolate utilized significantly (p< 0.05) more threonine and serine whereas V. atypica utilized significantly (p< 0.05) more aspartate. The defined medium supported growth of all of the Veillonella species tested and should enable further in-depth physiological studies to be conducted on the poultry Veillonella studies.