Geobacillus spp. and Bacillus spp., while Thermus ruber was isolated
from one system [32]. In the only published culture-independent
study of a full scale batch-fed ATAD system, the 16S rRNA clone
library generated contained sequences closely related to Bacillus
spp. and Paenibacillus spp. [58]. This study therefore undertook to
use culture-dependent and culture-independent methods to iden-tify which bacterial populations were present in two full scale ATAD
systems and, by a combination of fluorescence in situ hybridization
(FISH) and microautoradiography (MAR), attempted to understand
better their in situ physiology in the hope that this information
might eventually enable these processes to be better operated and
controlled.