Atrazine catabolism by a combined bacterial association (KRA30) under carbon- and nitrogen-limitations in a retentostat
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Updated: Jul 30, 2026

Immobilization of Multi-biocatalysts in Alginate Beads for Cofactor Regeneration and Improved Reusability
Published on: April 22, 2016
T K Ralebitso-Senior1, C Costa, W F M Röling
1International Centre for Waste Technology (Africa), School of Applied Environmental Sciences, University of Natal, Scottsville, South Africa. tralebitso@yahoo.com
Aims:
Nutrient-limited atrazine catabolism study in continuous cultures with biomass retention to mimic in situ environmental conditions and thus gain insight of the efficacy of biosupplementation/biostimulation to eliminate reduced herbicide bioavailability.
Methods And Results:
Carbon- and nitrogen-limited retentostat (1 and 5 l) cultivation of a combined atrazine (100 mg l-1)-catabolizing association KRA30 was made. As a nitrogen source, through citrate supplementation, increased herbicide catabolism resulted and was complete in the absence of NH4-N. Co-metabolism of the molecule in the presence of succinate was identified. Population characterization by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) indicated component species numerical dominance shifts in response to changes in nutrient limitation, mineral salts composition and biofilm formation, although the total species complement and catabolic potential were retained.
Conclusions:
Biomass and catabolic capacity maintenance, through cost-effective biosupplementation/biostimulation, should promote atrazine bioavailability and so ensure successful amelioration.
Significance And Impact Of The Study:
All planning, implementation and monitoring of bioremediation programmes should be underpinned by a combination of molecular and (continuous) culture-based methods.
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