- Volume 21, Issue 3, 1971

The deoxyribonucleic acids of 185 strains of phototrophic bacteria (47 strains of Rhodospirillaceae, 104 strains of Chromatiaceae, and 34 strains of Chlorobiaceae) have been examined by cesium chloride density gradient centrifugation. The calculated guanine plus cytosine moles percentages are given, and the taxonomic implications are described.

Veillonellaceae (order Eubacteriales) is proposed as the name of a new family to include three genera of presently known, anaerobic, gram-negative, coccal bacteria. It is herein proposed that Veillonella Prévot 1933 and Acidaminococcus Rogosa 1969 be transferred from Neisseriaceae and be included together with Megasphaera Rogosa 1971 in Veillonellaceae fam. nov. The type genus is Veillonella Prévot.

Peptococcaceae is proposed as a new family in the order Eubacteriales to include three genera of presently known gram-positive, anaerobic, coccal organisms: Peptococcus Kluyver and van Niel, Peptostreptococcus Kluyver and van Niel, and Ruminococcus Sijpestein. The type genus of this family is Peptococcus. Descriptions of these taxa are given, and where necessary the original descriptions have been expanded and brought up to date.

ATCC 12706 (strain S38A of Niven and Evans) is designated as the type strain of Lactobacillus viridescens Niven and Evans. A description of this strain is also given.

A search for a suitable strain to serve as the neotype for Micromonospora fusca Jensen 1932 has uncovered a number of Micromonospora strains which produce a dark-brown, agar-diffusible pigment and which are physiologically and morphologically similar to M. fusca. One of the strains resembling M. fusca is IMRU 3343 (= ATCC 27007), the type strain of Streptomyces purpureochromogenes (Waksman and Curtis 1916) Waksman and Henrici, 1948. [The strain of Streptomyces purpureochromogenus (sic) held at the Centraalbureau voor Schimmelcultures, Baarn, Netherlands, and S. purpureochromogenes ATCC 3343 have been identified as belonging to S. griseus, and they bear no relationship to IMRU 3343 or to the original description of Actinomyces purpeo-chromogenus (sic). Waksman and Curtis 1916.] It has been determined that the type strain (IMRU 3343) of S. purpureochromogenes is a micromonospora, and therefore this organism is transferred to the genus Micromonospora ørskov as M. purpureochromogenes (Waksman and Curtis) comb. nov. Because the species M. purpureochromogenes and M. fusca are so similar, their names are here regarded as subjective synonyms. The specific epithet purpureochromogenes has priority over fusca, and the correct name of this organism is therefore M. purpureochromogenes.

ATCC 27008 and ATCC 12452 are designated as neotype strains for Micromonospora coerulea Jensen 1932 and Micromonospora chalcea (Foulerton 1905) ørskov 1923, respectively. The data of earlier workers who studied these organisms are discussed, and additional characteristics considered useful for the identification of these species are presented.