Inter-Research
Aquatic Microbial Ecology

ABSTRACT: Interactions between Vibrio cholerae and 2 Mexican athalassohaline-lake bacteria assemblages were studied in laboratory microcosms with the presence or absence of protists. Pre-cultivated and harvested vibrios were added as the food for protists at a concentration of 10⁷ cells ml^-1. Total direct bacterial counts, colony forming units on a selective (thiosulphate-citrate-bile salts-sucrose) medium, and V. cholerae indirect fluorescent antibody (FA) direct counts were measured. Numbers of V. choleraedecreased faster in the microcosms inoculated with protists and, moreover, the proportion of non-culturable vibrio counts increased. Comparison between the ciliate feeding rates upon fluorescently labelled V. cholerae, Salmonella typhi and Shigella sp. showed that the ciliates fed preferably upon vibrios. Calculated grazing rates of Cyclidium glaucoma related to non-culturable but FA-positive V. cholerae were correlated to observed decrease in V. cholerae numbers.

KEY WORDS: Non-culturable Vibrio cholerae · Cyclidium glaucoma · Colpoda steinii · Clearance rate

Published in AME Vol. 13, No. 3 (1997) on September 11
Print ISSN: 0948-3055; Online ISSN: 1616-1564. Copyright © Inter-Research, Oldendorf/Luhe, 1997