FIG. 1.

DGGE profiles generated from gradient fractions (6 to 10) derived from RNA from activated sludge without amendment with ¹³C-labeled Tetrahymena rostrata (A) and with amendment with ¹³C-labeled T. rostrata (B). Fraction 6 has the highest buoyant density, while fraction 10 has the lowest. One template (see arrow) was only found in the treatment amended in with ¹³C-labeled T. rostrata, and was present through the gradient, including in the fractions with higher buoyant density. Sequencing confirmed this band as belonging to the ciliate Tetrahymena sp. (Ciliophora, Hymenostomatida, 98%).