Abstract
The fate of multiple cyanobacterial metabolites was assessed in two Australian source waters. The saxitoxins were the only metabolites shown to be non-biodegradable in Myponga Reservoir water, while microcystin-LR (MCLR) and geosmin were biodegradable in this water source. Likewise, cylindrospermopsin (CYN) was shown to be biodegradable in River Murray water. The order of ease of biodegradability followed the trend: MCLR>CYN>geosmin>saxitoxins. Biodegradation of the metabolites was affected by temperature and seasonal variations with more rapid degradation at 24°C and during autumn compared with 14°C and during winter. A microcystin-degrading bacterium was isolated and shown to degrade four microcystin variants within 4h. This bacterium, designated as TT25, was shown to be 99% similar to a Sphingopyxis sp. based on a 16S rRNA gene fragment. Isolate TT25 was shown to contain a homologue of the mlrA gene; the sequence of which was 99% similar to that of a previously reported microcystin-degrader. Furthermore, isolate TT25 could degrade the microcystins in the presence of copper sulphate (0.5mgL -1 as Cu 2+) which is advantageous for water authorities dosing such algicides into water bodies to control cyanobacterial blooms.
Original language | English |
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Pages (from-to) | 1149-1154 |
Number of pages | 6 |
Journal | Chemosphere |
Volume | 87 |
Issue number | 10 |
DOIs | |
Publication status | Published - Jun 2012 |
Keywords
- Biodegradation
- Cyanobacteria
- Cylindrospermopsin
- Geosmin
- Microcystins
- Saxitoxins