CONSISTENCY BETWEEN BACTERIAL PRODUCTIONS ESTIMATED FROM H-3 THYMIDINE AND H-3 LEUCINE INCORPORATION RATES IN NATURAL FRESH-WATERS

Bacterial production estimates from H-3-thymidine and H-3-leucine inco rporation rates were compared in various freshwater environments - lak es and rivers - showing a wide range of bacterial activities. The inco rporation rates were converted into bacterial production using the fol lowing factors, theoretically or experimentally calculated : 0.5 10(18 ) cells/mole thymidine incorporated into macromolecules and respective ly 900 and 1 080 g C/mole leucine incorporated into proteins for the r iver and the lake samples. There is significant correlation (r = 0.96, n = 102) between the incorporation rates of the two isotopes, and alt hough the two methods measure two different aspects of bacterial metab olism (DNA synthesis and protein synthesis), they gave quite concordan t estimates of production.