Abstract

Cheonho reservoir is a small and eutrophicated lake. The variation of BOD in the reservoir was correlated to the variation of chlorophyll-a. BOD was maximum (39.1㎍/L) at site 1 in July of 1995 when chlorophyll-a was the highest. β-Glucosidase activities ranged from 9 to 241 nM/h. β-Glucosidase activity varied in the following order:site 3>site 2>site 1>site 4. The β-Glucosidase activity of the site 4 was less than 50% of the other three sites. Organic matter was produced by algae at all sites but was not directly related with the increase of heterotrophic bacteria. β-Glucosidase activity showed a close correlation with the number of heterotrophic bacteria, indicating a tight coupling between algae and heterotrophic bacteria through agal organic production.

• Keywords: Algae; BOD; chlorophyll-a; β-glucosidase; heterotrophic bacteria