An annual cycle of abundance and activity of heterotrophic bacteria and abundance of hydrocarbonoclastic bacteria in Newfoundland coastal water

An annual cycle of abundance and activity was determined for bacteria in Newfoundland coastal water that is dominated by the Labrador Current. Both in abundance and activity, the population showed characteristics similar to those reported for bacteria in cold ocean environments. The number of bacter...

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Bibliographic Details
Published in:Canadian Journal of Microbiology
Main Authors: Powell, James C., Dabinett, Patrick E., Gow, John A.
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 1987
Subjects:
Online Access:http://dx.doi.org/10.1139/m87-066
http://www.nrcresearchpress.com/doi/pdf/10.1139/m87-066
Description
Summary:An annual cycle of abundance and activity was determined for bacteria in Newfoundland coastal water that is dominated by the Labrador Current. Both in abundance and activity, the population showed characteristics similar to those reported for bacteria in cold ocean environments. The number of bacteria per litre determined by the acridine orange direct count method ranged from an average low of 0.25 × 10 8 in winter to an average high of 2.8 × 10 8 in summer. Activity, determined by the kinetic method, was correlated with temperature. The average heterotrophic potential (V max ) was 3 ng glutamate. L −1 ∙h −1 in winter and 54.7 ng glutamate. L −1 ∙h −1 in summer. The average turnover times were 2632 and 256 h, respectively, during the same periods. The population of hydrocarbonoclastic bacteria, estimated by a most probable number method, constituted 4.4% of the viable bacterial population estimated by the standard plate count method, although the former were most abundant near the water's surface. The number of hydrocarbonoclastic bacteria was correlated with temperature and with V max of the heterotrophic bacterial population.