Allelopathic effect of Oocystis borgei culture on Microcystis aeruginosa

ABSTRACT

This study evaluated the possibility of using Oocystis borgei to prevent and control harmful algae blooms. Firstly, Microcystis aeruginosa and O. borgei were co-cultured to assess the competition for nutrients between them. Different physiological and biochemical parameters, such as growth, cell membrane permeability and esterase activities were determined in exudate culture experiment to investigate allelopathic effects of O. borgei culture and mixed cultures (O. borgei and M. aeruginosa) at different growth phase on harmful microalgae (M. aeruginosa). Results showed that O. borgei could significantly inhibited M. aeruginosa when volume ratios were 4:1 and 1:1 (M. aeruginosa: O. borgei) in co-culture experiment. Further, it was found that the membrane system of M. aeruginosa was disintegrated by the culture filtrate of O. borgei at exponential phase. In addition, esterase activities and photorespiration were significantly inhibited. In conclusion, O. borgei exhibited different allelopathic effects at different growth phase. Its exponential phase showed a significant inhibitory effect, while no inhibitory effect was observed at the decline phase.

GRAPHICAL ABSTRACT

KEYWORDS:

• Oocystis borgei
• Microcystis aeruginosa
• physiological characters
• allelopathy
• algal bloom

Acknowledgements

This study was supported by the Key Project of ‘Blue Granary Science and Technology Innovation’ of the Ministry of Science and Technology: [Grant Number 2020YFD0900205]; Research and Demonstration of Key Technologies in The Industrialization of Active Microalgae Products: [Grant Number KY 20180112]. We would like to thank the Guangdong Province Government, Guangdong Ocean University and the Laboratory of Ecology of Water Area and Aquaculture Environment for their financial support. We appreciate to Affiliated hospital of Guangdong Medical University for using JEM-1400 transmission electron microscope. Finally, we would like to thank David Kwame Amenorfenyo for his contribution to the language improvement of the article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Key Project of ‘Blue Granary Science and Technology Innovation’ of the Ministry of Science and Technology: [Grant Number 2020YFD0900205]; Research and Demonstration of Key Technologies in The Industrialization of Active Microalgae Products: [Grant Number KY 20180112].