- Volume 80, Issue 2, 1974

Zoospores of Phytophthora palmivora Butler aggregated without encysting within 2 min when they were suspended in water (Ko & Chase, 1973). Such zoospore behaviour was temperature-dependent with an optimum temperature of 16 °C. Aggregate formation also depended on both zoospore concentration and depth of suspension. We now report a similar behaviour of zoospores of Phytophthora capsici Leonian in water. The interaction between zoospores of P. palmivora and P. capsici was also investigated.

SUMMARY: Fifty-nine strains labelled Corynebacterium parvum were investigated by cell-wall agglutination tests using antisera to Propionibacterium acnes and P. granulosum. Fifty-two strains appeared to be serologically identical with P. acnes and three with P. granulosum; these identifications were confirmed by the results of fermentation and other metabolic tests. Of the remaining four strains, three were identified as P. avidum by fermentation tests, and by DNA/DNA homology determinations against reference strains of P. avidum, P. acnes and P. granulosum. One strain was identified as Actinomyces, probably A. naeslundii.

These results indicate that C. parvum should be regarded as a synonym of P. acnes.