The Range of the Colonial <i>Microcystis</i>’ Biomass for Shift to Diatom Aggregates Under Aeration Mixing and Low Light
In order to investigate non-cyanobacteria dominance succession from <i>Microcystis</i> blooms, particularly to diatom dominance, an experiment using varying colonial <i>Microcystis</i> biomasses expressed as bulk concentrations of 2.0, 4.0, 6.0, 8.0, 10.0, 12.0, 14.0, 16.0, 1...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-11-01
|
| Series: | Diversity |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1424-2818/16/11/695 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | In order to investigate non-cyanobacteria dominance succession from <i>Microcystis</i> blooms, particularly to diatom dominance, an experiment using varying colonial <i>Microcystis</i> biomasses expressed as bulk concentrations of 2.0, 4.0, 6.0, 8.0, 10.0, 12.0, 14.0, 16.0, 18.0, 20.0, 22.0, and 24.0 mL L<sup>−1</sup> was undertaken under continuous aeration mixing in a greenhouse during a hot summer where shading had reduced light level by 97%. The results showed that the algal shift process was affected by the initial biomass of the colonial <i>Microcystis</i>, and the algal community diversified. When the <i>Microcystis</i> bulk concentration was between 2.0 and 16.0 mL L<sup>−1</sup>, the bloom became dominated by diatom <i>Nitzschia palea</i>, which aggregated on the mucilage sheathes of the <i>Microcystis</i> colonies. The diatom density at bulk concentration biomass of 2.0 mL L<sup>−1</sup> reached a maximum at 2.8 × 10<sup>5</sup> cells mL<sup>−1</sup> on day 27. When the bulk concentration was at 18.0–24.0 mL L<sup>−1</sup>, no diatom dominance appeared. The shift from a <i>Microcystis</i> bloom to diatom dominance was affected by the initial <i>Microcystis</i> biomass, and the most suitable bulk concentration biomass for colonial <i>Microcystis</i> was at 2–12 mL L<sup>−1</sup>, in which the chlorophyll-<i>a</i> level was about from 285 to 1714 μg L<sup>−1</sup>. The mechanism underlying this algal shift may be that the low light and nutrient levels in the <i>Microcystis</i> bloom promoted diatom aggregation growth on the mucilage sheaths of <i>Microcystis</i> colonies under continuous aeration mixing. |
|---|---|
| ISSN: | 1424-2818 |