- Volume 128, Issue 4, 1982

Corynebacterium pyogenes (Glage) differs to such an extent from the type species of Corynebacterium, Corynebacterium diphtheriae (Lehmann and Neumann), that it cannot be retained in this genus. Numerical phenetic and chemical data indicate a close relationship between Corynebacterium pyogenes and the species Actinomyces bovis (Harz). It is proposed that Corynebacterium pyogenes be reclassified in the genus Actinomyces, as Actinomyces pyogenes (Glage) comb.nov.

Slow reduction of methylene blue under H2, after treatment with NaF + EDTA, distinguished Hup− (uptake hydrogenase negative) from Hup+ colonies of Azotobacter chroococcum on plates.

The technique of direct probe mass spectrometry is described together with its application to the analysis of 50 strains of Gram-negative bacteria representing seven genera. Thirty-six of these strains were analysed in duplicate, and the 72 spectra held in a computer library. The intensities of 63 ions from each of the spectra were analysed by discriminant analysis techniques and all seven groups could be distinguished by as few as six ions. A set of 29 strains, 15 of which were already in the data base, were used as unknowns to challenge the library on two separate occasions. The success rate of these challenges was 97% and 90% using the full spectra, but only 72% and 62% using the selection of six ions. Possible explanations for this are discussed as well as the scope and limitations of the method as a means of characterizing micro-organisms.

Nineteen strains of Corynebacterium sensu stricto, 23 received as Corynebacterium equi or Rhodococcus equi, marker cultures of Arthrobacter, Brevibacterium, Bacterionema matruchotii, Cellulomonas flavigena, Kurthia zopfii, Listeria denitrificans, Microbacterium lacticum, Rhodococcus rubropertinctus and 88 representatives of Mycobacterium, Nocardia, Rhodococcus and the ‘aurantiaca’ taxon were the subject of numerical phenetic analyses using 92 characters. The data were examined using the simple matching (S SM ) and Jaccard (S J ) coefficients and clustering was achieved using the average linkage algorithm. With a single exception, strains containing meso-diaminopimelic acid, arabinose, galactose and mycolic acids were recovered in five aggregate clusters corresponding to Corynebacterium sensu stricto, Mycobacterium, Nocardia, Rhodococcus and the aurantiaca taxon. Most of the Corynebacterium (Rhodococcus) equi strains formed a good taxospecies which included the type strain of Corynebacterium hoagii. The numerical data, and the results of earlier chemical and genetical studies, also provide sufficient evidence for the transfer of Bacterionema matruchotii to Corynebacterium sensu stricto as Corynebacterium matruchotii comb.nov. and for the recognition of Rhodococcus globerulus sp.nov. for some strains previously classified as Rhodococcus rubropertinctus (Hefferan) Goodfellow & Alderson. The classification of the remaining marker strains correlates well with other major developments in coryneform taxonomy.

Two-dimensional thin-layer chromatography of whole-organism acid methanolysates of Mycobacterium chelonei gives a characteristic pattern of two non-polar mycolic acid methyl esters which allows the organism to be distinguished from all other mycobacteria including Mycobacterium fortuitum. The mycolic acids from Mycobacterium chelonei were composed of approximately equal amounts of a diunsaturated α-mycolate and a lower molecular weight α′-mycolate, though minor amounts of a different α-mycolate were also detected. These mycolic acids are the first examples of natural mixtures from mycobacteria lacking major amounts of acids having oxygen functions in addition to the 3-hydroxy acid unit.

Hybrids were prepared between 14C-labelled rRNA from each of nine species of Gram-negative bacteria and the DNA of Chromobacterium fluviatile. Two parameters were determined for each hybrid - the T m(e), which is the temperature at which 50% of the hybrid was denatured, and the percentage of rRNA bound under defined stringent conditions. The former gives a measure of the stability of the duplex once formed and the latter probably reflects the amount of the genome involved in the coding of rRNA. These parameters were used as a measure of the relatedness of C. fluviatile to each of the other nine species. The results suggest that C. fluviatile is more closely related to C. violaceum than to any other species tested. The taxonomic relationship of C. fluviatile to other Gram-negative bacteria was assessed by incorporating the results into a database already published by De Ley et al. (1978) , and the use of principal components analysis was explored as an alternative way of presenting such data. This analysis confirmed the isolated position of C. fluviatile but, until further isolates are studied, it seems best to retain the species in the genus Chromobacterium.

A number of cyanobacterial phycoerythrocyanins were isolated and characterized with respect to spectroscopic properties and chromophore content. All were similar to the phycoerythrocyanin of Anabaena PCC 6411 and cross-reacted strongly with an antiserum prepared against that protein. The synthesis of phycoerythrocyanin was not controlled by a complementary chromatic adaptation mechanism in nine strains tested, but its synthesis appeared to be affected by light intensity. A survey of 240 strains of cyanobacteria revealed that no strain synthesized both phycoerythrocyanin and phycoerythrin and that phycoerythrocyanin was largely confined to those strains which can form heterocysts. Phycoerythrocyanin may be a taxonomically useful marker for certain strain clusters of this cyanobacterial grouping. Spectroscopic properties and chromophore compositions of several cyanobacterial phycoerythrins were also determined. At present, the ability to synthesize phycoerythrin and the capacity to exhibit complementary chromatic adaptation responses are widely distributed traits of limited taxonomic usefulness.