The bactericidal activity of long-chain fatty acids on mycobacteria was examined by exposing the organisms to these acids at 0.04 mM in 0.05 M acetate buffer (pH 5.6) . The lethal effect of saturated fatty acids was related to the chainlength of hydrocarbon, C_{14: 0} being the strongest in the activity and longer and shorter fatty acids being less active. Unsaturation, isomerism and the presence of α-hydroxy group were found to be other factors governing the activity. The lethal effect was greater in the order of C_{18: 3}>C_{18: 2}>C_{18: 1 (cis}) >C_{18: 1 (trans}) >α-OH C_{18: 0}>C_{18: 0}. C_{20: 4}was placed between C_{18: 3}and C_{18: 2}in this respect. Esterification of C_{14: 0}, C_{18: 1}and C_{20: 4}to methyl esters and cholesteryl esters abolished completely the bactericidal activity of these acids, suggesting the requirement of carboxyl group for the activity. The relationship between the fatty acid structure and the lethal effect was discussed in reference to these observations.

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A sulfhydryl-dependent protease (SHP) was purified from a culture ofClostridium botulinumtype F. The enzyme can activate type E progenitor toxin completely but type B progenitor toxin only partially. This may suggest that SHP by itself could completely activate the toxin of proteolyticC. botulinumtypes A and F in culture. The toxicity of type E progenitor toxin potentiated by the treatment with SHP persisted, whereas that of derivative toxin decreased rapidly by further incubation with SHP. This may indicate that only the progenitor toxin, the complex of the toxic and nontoxic components, activated by SHP withstands the subsequent exposure to the enzyme in cultures of proteolyticC. botulinum.

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A new virus was isolated from cynomolgus monkeys for laboratory use imported from Indonesia in July, 1973.
The virus agglutinated erythrocytes of some avian and mammalian species and hemolyzed chick erythrocytes. The virus was eluted from the surface of chick red blood cells by its neuraminidase activity. The virus was inactivated by ether; its nucleic acid was RNA. On electron micrographs, the particles varied from 250 to 400 nm in diameter, being covered with envelopes in which the surface projections were embedded. The diameter of inner helical structure was about 18 nm.
These observations indicate that the virus belongs to a group of paramyxoviruses. On the basis of serological examinations, this virus can be identified as a new virus having some relations with Yucaipa or Bangore viruses. This virus is designated as“Murayama virus”from the name of the place where it was isolated.

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