Summary: A new species Streptococcus pleomorphus is described. It is obligately anaerobic and classified in the genus Streptococcus because it is a Gram-positive coccus growing in pairs and chains, with a homolactic fermentation of glucose producing l-lactic acid. The GC content of the DNA is 39 mol%. The organism has been mainly isolated from chickens, turkeys and ducks.
Summary: The β-lactamase isoelectric focusing patterns of 37 strains of Yersinia enterocolitica from various serological and biochemical groups were examined. Strains of different serological groups generally had different patterns, but those of serological groups 1, 2, 3 and 9 were identical.
Summary: The immunoglobulin fraction of antiserum prepared against a homogeneous preparation of 3-carboxymuconate cyclase from Aspergillus niger l6 was used to study the serological relatedness of the enzyme in crude extracts of other fungi. Immunodiffusion and immmuno-electrophoresis experiments confirmed the homogeneity of the pure A. niger l6 cyclase, its serological identity with the same enzyme in other strains of A. niger and the complete absence of any cross-reaction with the analogous 3-carboxymuconate cycloisomerase from Pseudomonas putida and Nocardia opaca. Extensive cross-reactions were observed with the cyclases from other species of Aspergillus and Penicillium. When such cross-reactions were examined quantitatively by the precipitin technique, several genera believed to be taxo-nomically related to Aspergillus and Penicillium on morphological grounds showed cross-reacting cyclases. Within the genera there was a broad correlation of serological relationships with morphological subdivisions. These correlations were considerably better than can be achieved by determinations of DNA base compositions because most of the genera examined have GC ratios of 50 to 55 mol%. Crude extracts of two taxonomically unrelated Basidiomycetes showed no serological relatedness to the antisera.