Searching for indigenous anaerobic ammonium oxidizing (anammox) bacteria in South African habitats: Pretoria region

Abstract

In South Africa, the information about the distribution and activity of anaerobic ammonium oxidizing (anammox) bacteria is very limited and anammox systems have not yet been tested and implemented. In this study, the existence and diversity of the anammox bacteria from various South African habitats are investigated. Batch systems were used to enrich anammox biomass from sludge collected from three Pretoria municipal wastewater treatment works. Anammox activity was tested and detected in two of the three wastewater treatment works after 90 days of primary enrichment. The activity was confirmed by consumption of both NH4+ and NO2− in the system. The presence of anammox bacteria was also confirmed by polymerase chain reaction (PCR) amplification of the 16s rRNA of the anammox using anammox-specific primers. All clones retrieved were closely related to Brocadia species and were most abundant in all habitats tested. The maximum growth rate of anammox was also estimated on both experiments using a relatively new model.