Chemically defined media for growing anaerobic bacteria of the genus Veillonella

Abstract

A chemically defined medium for Veillonella parvula and V. alcalescens is described. Some nutritional aspects of the two strains used were examined: the optimum concentration of reducing agents, the requirements for amino acids, diamines, vitamins and other growth factors, and the conditions needed for well balanced nutrition. No specific requirements for single amino acids were observed. A combination of L-cysteine, DL-aspartic acid, L-glutamic acid, L-serine and L-tyrosine, promoted growth. In V. alcalescens, serine could substitute both arginine and tryptophan (or histidine). No growth was obtained with ammonium salts as the sole N source. Decarboxylation of L-ornithine, L-lysine and L-arginine was not demonstrated in the Veillonella parvula strain, which required putrescine or cadaverine for growth. Spermine, spermidine, L-lysine, L-ornithine and L-arginine, could not substitute putrescine in Veillonella parvula. Veillonella alcalescens, which does not require putrescine in the medium, was able to decarboxylate L-ornithine while forming putrescine.

Emergent survival and extinction of species within gut bacterial communities

“…The enrichment of supernatant metabolites and alpha diversity were both greater when inoculation contained probiotics. While the inclusion of pathogens had a negative effect on metabolite richness and community diversity, virtually all pathogens were undetectable in the final communities, emphasising the decisive role of transient community members as observed in other studies 44,45 .…”

“…For the assembly of stable bacterial communities previously described defined and minimal media (MM) have been used: B. thetaiotaomicron MM 59 , C. perfringens MM 60 , E. coli MOPS MM1 and MM2 10,61 , V. parvula defined medium 62 , Lactic Acid Bacteria medium (LAB 63 ), defined Gut Microbiota Medium (dGMM), dGMM+LAB and all recently published modified versions of the latter 10 : dGMM+LAB containing only 10% (w/v) of amino acids, lower amounts of minerals and vitamins, monosaccharides or mucin as solely carbohydrate source, additional mucin and media excluding short chain fatty acids (SCFA) or aromatic amino acids. For complete media formulations, see Supplementary Materials in 10 .…”