- Volume 36, Issue 3, 1986

The genus Aeromonas is currently allocated, primarily on the basis of phenotypic expression, to the eubacterial family Vibrionaceae. However, a sizeable collection of molecular genetic evidence, including 16S ribosomal ribonucleic acid catalog, 5S ribosomal ribonucleic acid sequence, and ribosomal ribonucleic acid-deoxyribonucleic acid hybridization data, indicates that Aeromonas spp. possess an evolutionary history sufficiently different from that of the Vibrionaceae to warrant removal from this family. The phylogenetic locus (i.e., intermediate between the families Enterobacteriaceae and Vibrionaceae) and phylogenetic depth of the genus Aeromonas suggest that Aeromonas spp. represent a discrete family of eubacteria, for which the name Aeromonadaceae fam. nov. is proposed.

The name of the producer of the macrolide antibiotic rosaramicin, Micromonospora rosaria NRRL 3718T (T = type strain), was not included on the Approved Lists of Bacterial Names because the original publication did not contain a full description of this strain. Following its first appearance in the literature and its subsequent availability, M. rosaria NRRL 3718 frequently appeared in studies as a comparative organism when new antibiotic-producing species of Micromonspora were described. Therefore, we formally revive the name M. rosaria, present a full species description, and designate strain NRRL 3718 as the type strain.

Lactobacillus animalis comprises homofermentative strains from animals which are recognized by their polypeptide patterns. Physiologically these strains resemble Lactobacillus murinus and Lactobacillus ruminis, but are distinguished from the former by guanine-plus-cytosine content and from the latter by peptidoglycan type. Deoxyribonucleic acid-deoxyribonucleic acid homology confirmed that L. animalis is a homogeneous taxon distinct from L. acidophilus.

The genome sizes of the type strains of the sterol-requiring organisms Anaeroplasma abactoclasticum and Anaeroplasma bactoclasticum and of a sterol-nonrequiring obligately anaerobic mollicute, strain 161, were determined by the renaturation method of Wetmur and Davidson. The genome molecular weights of the three strains were almost identical (viz., approximately 109). This value is identical to the genome molecular weights of members of the family Spiroplasmataceae in the order Mycoplasmatales and of the family Acholeplasmataceae in the order Acholeplasmatales. The guanine-plus-cytosine contents of the deoxyribonucleic acids of A. abactoclasticum, A. bactoclasticum, and strain 161, as determined by the buoyant density method, were found to be 30.1, 32.8, and 39.9 mol%, respectively, thereby confirming results reported previously by other workers. The deoxyribonucleic acid base composition and genomic size are among the data needed to clarify the taxonomic status of the genus Anaeroplasma and of the sterol-nonrequiring anaerobic organism strain 161.

The published descriptions of Klebsiella planticola Bagley, Seidler, and Brenner 1982 and Klebsiella trevisanii Ferragut, Izard, Gavini, Kersters, De Ley, and Leclerc 1983 are very similar. The reactions given by the type strains of K. planticola and K. trevisanii were identical when these strains were submitted to 51 common tests and in 118 of 119 nutritional tests. The level of deoxyribonucleic acid relatedness between the two type strains was 79 to 94% (nitrocellulose filter method) or 70 to 104% (S1 nuclease method) depending on which deoxyribonucleic acid was tritium labeled. Heteroduplexes showed a thermal stability very close to that of homoduplexes. Thus, K. planticola and K. trevisanii are subjective synonyms. Since K. planticola has priority over K. trevisanii, K. planticola should be the only name used to refer to the species formerly designated K. planticola or K. trevisanii.

We describe Clavispora opuntiae, a new cactophilic species of yeast with a wide distribution in necrotic tissue of Opuntia species. The more than 200 strains recognized thus far come from eastern Australia, Hawaii, Venezuela, Spain, various islands in the Caribbean Sea, Mexico, and southwestern areas of the United States. The new species is heterothallic and occurs in nature exclusively in the haploid state. Upon conjugation of complementary mating types, asci are produced with one or two clavate, warty ascospores (as observed by electron microscopy) that are very rapidly released from the asci. Testing for mating types has indicated that one mating type (arbitrarily designated h+ predominates in Australia, Haiti, Dominican Republic, and Montserrat, whereas in all other areas both mating types are found, sometimes in the same plant. The guanine-plus-cytosine content range for the nuclear deoxyribonucleic acids of 11 strains is 43.0 to 44.1 mol% (average, 43.5 mol%; standard deviation, 0.4 mol%). The type strain of C. opuntiae is strain UCD-FST 77-279 (= ATCC 42172 = CBS 7068), and the complementary mating type is strain UCD-FST 78-540A (= ATCC 42173 = CBS 7069).

A proposal is made to modify Rule 12a of the Bacteriological Code so as to legitimatize specific epithets which are based on more than one concept.

Methanococcus mazei, the type species of the genus Methanococcus, is transferred to the genus Methanosarcina as Methanosarcina mazei, and the genus Methanococcus is conserved with a new type species, Methanococcus vannielii.

The type species Methanosarcina methanica has been rejected by the Judicial Commission of the International Committee on Systematic Bacteriology, and the genus Methanosarcina has been conserved with Methanosarcina barkeri as the type species.