Integrating acidogenic fermentation and microalgae cultivation of bacterial-algal coupling system for mariculture wastewater treatment

In this study, Bacterial-Algal Coupling System, a method integrated acidogenic fermentation (AF) and microalgae cultivation, was applied to the mariculture wastewater (MW) treatment. The MW was acidogenic fermented at different initial pH (4.0-10.0), and different dilution rate (5%-20%) of AF effluent was used for Chlorella vulgaris cultivation. The results showed that the maximum biomass production (5.6 g/L) of microalgae was obtained with 10% AF effluent. Ammonium, phosphate and volatile fatty acids could be metabolized by microalgae. More specifically, acetic acid and propionic acid were utilized prior to butyric acid and valeric acid. To better understand the synergy of heterotrophic metabolism and photosynthesis, the activities of Rubisco and citrate synthase were revealed to provide additional insight for nutrients recovery from MW by mixotrophic cultivation of microalgae.

Automated summary

This study investigated the application of a Bacterial-Algal Coupling System in treating mariculture wastewater, showing that acidogenic fermentation and microalgae cultivation under specific conditions can enhance biomass production of microalgae and promote the metabolism of nutrients in wastewater. The activities of Rubisco and citrate synthase were found to provide additional insights for nutrients recovery through mixotrophic cultivation of microalgae.