SciELO - Scientific Electronic Library Online

 
vol.103 issue3-4Biogenic volatile organic compounds: The state of knowledge in southern Africa and the challenges for air quality managementDocumenting lichen-induced mechanical weathering of quartzitic sandstone at Kaapsehoop, Mpumalanga author indexsubject indexarticles search
Home Pagealphabetic serial listing  

South African Journal of Science

On-line version ISSN 1996-7489

Abstract

RAMDHANI, Nishani  and  BUX, Faizal. Functional characterization of heterotrophic denitrifying bacteria in activated sludge. S. Afr. j. sci. [online]. 2007, vol.103, n.3-4, pp. 113-116. ISSN 1996-7489.

Wastewater treatment facilities are largely accountable for the detrimental enrichment of water bodies with nitrogenous compounds, resulting in eutrophication. Denitrification is of interest as a means of removing nitrates and nitrites from water supplies because they are also hazardous to human health. The integration of biological nutrient removal into conventional wastewater treatment processes has, however, failed to take into sufficient consideration the role of key microorganisms present, specifically denitrifying bacteria. The purpose of the study reported here was to group such heterotrophic denitrifying bacteria using a series of biochemical and molecular analyses, to achieve an improved understanding of their functions. The role of the denitrifying bacteria in reducing nitrate and nitrite was monitored using the colorimetric nitrate reduction test. The genetic diversity of the culture collection was investigated by the use of denaturing gradient gel electrophoresis (DGGE), which enabled the creation of a microbial population profile of eight predominant isolates. Batch experiments were conducted on these isolates, the results of which ultimately confirmed their classification according to their respective functions, namely, incomplete denitrifiers, true denitrifiers, sequential denitrifiers, and exclusive nitrite reducers.

        · text in English     · English ( pdf )

 

Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License