Non-Sporulating Anaerobic Bacteria of the Intestinal Tract : II. Growth-Facilitating Factors.

The statements of Castellani and Chalmers (1919) and Bergey (1934) that the Bacteroides show good growth on ordinary laboratory media have been quite misleading, for difficulty of cultivation has been among the most trying problems encountered in working with the non-sporulating anaerobic bacteria. Harris (1901-1905) and Beaver, Henthorne and Macy (1934) have especially emphasized this point, and several other workers have considered survival of pure cultures for more than a month or two as worthy of special comment. There has been little agreement among investigators concerning the conditions best adapted for the growth of these organisms, and little information is available as to which materials actually contain nutrients available for their use. On a more or less empirical basis, complex infusions, body fluids and tissues have been used in a great variety of formulae. Further inconsistencies have arisen from the use of numerous kinds of peptones, and of reactions varying from distinctly acid to markedly alkaline. The usefulness of most of these media has been limited by their lack of clarity, heat lability and complexity. Often growth appears to have been delicate, slow to appear, and difficult to observe.