How to Cite
Abstract
Nitrosomonas species are the main organisms involved in the oxidation of ammonium to nitrite in nature. The traditional method for enumerating Nitrosomonas species is via the Most Probable Number (MPN) Technique. However, this is a slow and labourious method due to the slow growth rate of nitrifiers. Also, the method does not distinguish different species of nitrifiers. Oligonucleotide probes are now used as a method for identifying particular species of nitrifying bacteria. However, the correlation between these methods is unclear. Sludge wastewater sample from a bioreactor was used to study the potential correlation between the MPN technique and the oligonucleotide probe technique. In order to investigate this relationship, multiple replicate dilutions of the sludge wastewater were made and each dilution was grown and processed using the MPN technique. After a period of growth, a record was made of the presence or absence of ammonia oxidation. RNA was extracted from these growth samples were probed with 16S rRNA specific probes Nso 190 6 and Nsm 156. It was found that the original sludge sample had 1.4 x 10 viable cells/ 100mL 5 6 with 95% confidence lower limit of 6.1 x 10 and an upper limit of 2.8 x 10. However, the poor integrity of the isolated RNA prevented any identification of Nitrosomonas species in the MPN sample.