Yoshio Yoshimura

Mutanolysin, Bacteriolytic Agent for Cariogenic Streptococci: Partial Purification and Properties

Mutanolysin partially purified from the culture filtrate of Streptomyces globisporus 1829 consists of two main lytic enzymes with an isoelectric point near pH 8.5 and 10, respectively, and proteolytic enzyme is associated with the latter lytic enzyme. Mutanolysin exhibited maximal lytic activity at 60 C in the pH range 6.5 to 7.0 and was stable at 50 C in the acid range. N-bromosuccinimide caused complete inhibition of lytic activity at 1 mM, whereas calcium and magnesium ions at the same concentration caused activation. Mutanolysin had lytic or bactericidal activity against the living cells of Streptococcus mutans, Streptococcus salivarius, Streptococcus sanguis, Lactobacillus acidophilus, and Actinomyces viscosus, which are considered to be etiologic agents of dental caries, but had no activity against S. aureus and all gram-negative strains tested. The lytic activity was well retained in human saliva. Digestion of the cell walls of S. mutans BHT by mutanolysin was accompanied by the liberation of free amino groups and reducing sugars. Mutanolysin may be expected to be a useful agent for dental caries control. Images

Studies on Production of Biotin by Microorganisms:Part III. Effect of Adenine on Accumulation of Biotin Vitamers

During the course of the study on biotin vitamers production by a hydrocarbon-utilizing bacterium, strain 5–2 (Pseudomonas sp.), it was found that crude RNA-alkali-hydrolyzate from yeast increased the accumulaion of biotin vitamers, most of which was determined as desthiobion, and that adenine in the crude RNA-alkali-hydrolyzate was a potent stimulator. Effect of adenine on biotin vitamers accumulation was observed in the medium with either hydrocarbon or glucose as a sole carbon source. The accumulation of total biotin vitamers by some other bacteria was also increased by adenine but that of true biotin was scarcely increased or inhibited by adenine.The role of adenine on the accumulation of biotin vitamers was investigated with non-proliferating cells of strain 5–2, and it was supposed that adenine would not only inhibit the accumulation of true biotin but, as a result, cause the large accumulation of biotin vitamers which might be intermediates of biotin synthesis. When the medium was supplemented with...