Dual-bioaugmentation strategy to enhance the formation of algal-bacteria symbiosis biofloc in aquaculture wastewater supplemented with agricultural wastes as an alternative nutrient sources and biomass support materials

Abstract

This study performs an integrated evaluation of the formation and distribution of algal-bacterial bioflocs in aquaculture wastewater supplemented with agricultural waste, together with an assessment of their behavior in the microbial community and of the water quality of the system in which a new bioaugmentation strategy was applied. Results indicated that the dual bioaugmentation strategy via the consortium addition of bacteria and microalgae had the highest formation performance, providing the most compact biofloc structure (0.59 g/L), excellent settleability (71.91%), and a large particle diameter (4.25 mm). The fed-batch supplementation of molasses and rice bran, in terms of changes in the values of COD, NH₄⁺, NO₃^-, and PO₄^3-, stimulated the formation of biofloc through algal-bacterial bioflocs and microbe-rice bran complexes within a well-established microbial community. These findings provide new insight into the influence of bioaugmentation on the formation of an innovative algal-bacterial biofloc.

Keywords: Algae; Bacteria; Bioaugmentation; Biofloc; Microbial community; Wastewater.