Work

Allelopathic Interference of the Cyanobacterium Raphidiopsis raciborskii Exudates on Photosynthetic Traits of Photosynthesizing Microorganisms

Year: 2026

Type: article

Abstract: Raphidiopsis raciborskii (formerly Cylindrospermopsis raciborskii) is a bloom-forming cyanobacterium that employs the production of toxins and other secondary metabolites as a competitive and allelopathic strategy. This study evaluated the effects of exudates from R. raciborskii cultivated under three nitrogen-to-phosphorus (N:P) ratios on the photosynthetic performance of Limnothrix sp. (cyanobacterium), Chlorella sp. (green algae), and Raphidocelis subcapitata (green algae), using pulse-amplitude-modulated (PAM) fluorometry. Rapid light curves (rETR) obtained under different N:P ratios and across the three target species exhibited similar response patterns. Likewise, effective quantum yield (ΦPSII), regulated (Y(NPQ)) and non-regulated (Y(NO)) energy dissipation showed comparable profiles among treatments after 24 h of exposure. Overall, the results of the present study indicate that, within the 24 h exposure period and based on the fluorescence parameters measured, exudates produced by R. raciborskii under the tested nutrient conditions did not cause measurable alterations in the photosynthetic performance of the three evaluated species.

Source: Limnological Review

DOI: 10.3390/limnolrev26010009

Authors: Camila Nader, Maria Cecília Miotto, Carlos Yure B. Oliveira, Leonardo R. Rörig

Institution: Universidade Federal de Santa Catarina

Language: English

Topic: Aquatic Ecosystems and Phytoplankton Dynamics

Subfield: Environmental Chemistry

Field: Environmental Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,207

Funders: Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Universidade Federal de Santa Catarina