Application of quantitative RT-PCR to determine the distribution of Microthrix parvicella in full-scale activated sludge treatment systems.
Three wastewater treatment plants in South Africa were investigated to understand the phylogeny and distribution of Microthrix parvicella using real-time polymerase chain reaction (RT-PCR). The phylogenetic analysis of the 16S rRNA of M. parvicella revealed 98% to 100% homology of South African clones to M. parvicella reported in Genbank. The standard curves for RT-PCR showed R2 values greater than 0.99, accurate for quantification. The relative occurrence of M. parvicella 16S rRNA gene copies in the three wastewater treatment plants was in the range 0% to 3.97%. M. parvicella copies increased when the environmental temperature (< or =20 degrees C) and food/microorganism (F/M) ratio was low. The M. parvicella 16S rRNA copies could be positively correlated to the sludge volume index at low temperature. At higher temperature, there was a rapid reduction in M. parvicella population irrespective of other favorable factors, indicating the strong influence of temperature on filamentous proliferation. RT-PCR has potential applications in wastewater treatment plants to monitor sudden shift in the microbial population and assessing the plants efficacy.
Department of Biotechnology and Food Technology, Durban University of Technology, South Africa. sheenas@dut.ac.za
S K Sheena
SK
Kumari
Z
Z
Marrengane
F
F
Bux
D039903:Actinobacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000382:microbiology*; D013019:South Africa; D013696:Temperature
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012722:Sewage