Conditions for quantitative gas-liquid chromatography (GLC) analysis of madurose (3-O-methylgalactose) and other sugars in small amount of actinomycete whole cells were established for taxonomic use. Cell hydrolysis with trifluoroacetic acid followed by GLC using a capillary column made it possible to analyze whole-cell sugars of 1mg of dried cells quantitatively. Under the conditions established, alditol acetates derived from madurose as well as from other neutral sugars, such as rhamnose, arabinose, xylose, 3-O-methylmannose, mannose, galactose and glucose, were well separated from each other on GLC. When six strains of actinomycetes including Kitasatosporia strains were examined for the quantitative analysis, madurose was detected in cells of Kitasatosporia setae KM-6054, K. phosalacinea KA-338 and K. griseola AM-9660, as well as Actinomadura madurae IFM 78 and Streptosporangium roseum JCM-3005, but not in Streptomyces griseus IFO-12875.
Sugar composition of whole cells and cell wall preparations of the family Pseudonocardiaceae, mycolate-less wall chemotype IV actinomycetes, was examined to clarify the taxonomic significance of cell-wall sugars. Among the strains of the genera examined, cell wall types of Actinopolyspora, Saccharopolyspora and Amycolata were confirmed to be chemotype IV/A, however, those of Pseudonocardia, Amycolatopsis, Saccharomonospora, Pseudoamycolata, Actinokineospora and Kibdelosporangium were found to be III/A, and that of Saccharothrix to be III /A or III/C. Thus, the family Pseudonocardiaceae, which was proposed for the closely related genera on the basis of 16S rRNA sequencing studies, was indicated to include organisms with wall chemotypes III and IV, and the description of the family should therefore be emended.
Organisms of genus Micromonospora are endowed with some peculiarities among actinomycetes. It was discerned for the metabolites, the spores, the cell wall and the growing conditions. Various types of antibiotics and enzyme inhibitors were found in our screening program, suggesting the organisms to be promising sources of useful drugs. More than 50% of the single spores on vegetative mycelia survived after 20 min of moist heating at 60°C, and also more than 10% did after 30 min of treatment at 30°C with solutions containing 60% polar solvents. The cell wall was constituted of a peptide subunit glycyl-D-glutaminyl-meso-diaminopimelyl-D-alanine, a direct cross-linkage between D-alanine and meso-diaminopimelic acid, N-glycolylmuramic acids, and ribitol teichoic acids containing arabinose and xylose. These characteristics, together with some physiological properties, were discussed in comparison with those of other genera in Actinomycetales.
Findings on Streptomyces through the author’s 35-years studies were outlined. 1. On the basis of the morphological characteristics of aerial mycelia and sporiferous hyphae, the genus Streptomyces was divided into eight morphological types. The four of them were further subdivided by the morphological features of spirals. 2. Streptomycin 6-phosphate was produced in the cell of Streptomyces griseus. This compound had no antibiotic activity and was transformed to streptomycin by dephosphorylation with the specific alkaline phosphatase at the periplasmic space or outside of the cell. 3. S. griseus produced streptomycin-6-kinase in the cell. This enzyme contributed to self-protection of the streptomycin producer by inactivating streptomycin and liberating ribosome-bound streptomycin. 4. Suppression of the phospholipid cycle of cell wall synthesis enhanced streptomycin production.