COMPARISON OF BATCH CULTURE-GROWTH AND FERMENTATION OF A POULTRY VEILLONELLA ISOLATE AND SELECTED VEILLONELLA SPECIES GROWN IN A DEFINED MEDIUM

The objective of this study was to develop a defined medium for quanti tating nutritional requirements and fermentation products of a poultry cecal isolate of Veillonella and to compare these parameters with rep resentative Veillonella species. The poultry isolate is one of 29 orga nisms from a continuous-flow culture that has been shown to be effecti ve against Salmonella colonization in broilers. When the Veillonella s pecies were grown in anaerobic batch culture, propionate and acetate w ere the only volatile fatty acids detected. Lactate was needed to prov ide energy for the growth of the Veillonella in the defined medium. Th e 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 aminoacid supplemented de fined media. Cultures of the Veillonella species in the defined medium grown with supplemented amino acids aspartate, threonine, arginine, a nd 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 m ay have different amino acid preferences. For nearly all of the amino acid supplemented media combinations the poultry isolate utilized sign ificantly (p < 0.05) more threonine and serine whereas V. atypica util ized significantly (p < 0.05) more aspartate. The defined medium suppo rted growth of all of the Veillonella species tested and should enable further in-depth physiological studies to be conducted on the poultry Veillonella studies. (C) 1997 Academic Press.