In this study, considering the enhancement potential of microalgae and MBRs for wastewater treatment, the microalgae Haematococcus pluvialis, which is a freshwater species of Chlorophyta with a high capacity to synthesize astaxanthin, was bioaugmented into an aerobic MBR to investigate its potential on treatment of antibiotics in wastewater, reducing membrane biofouling, and impact on the microbial community structure. For this purpose, two control MBRs, with and without antibiotics, alongside an MBR bioaugmented with H. pluvialis, were set under mesophilic conditions, using inoculum from a local wastewater treatment facility and synthetic wastewater. The common antibiotics sulfamethoxazole (SMX), tetracycline (TET) and erythromycin (ERY) were selected to investigate removal efficiencies by Haematococcus pluvialis in an MBR for this study. In the bioaugmented reactor, membrane biofouling was delayed by 33% and chemical oxygen demand removal increased by 6%. The highest removal of antibiotics was observed for TET with a 20% enhancement from 69.75% (C2) to 89.73% (HP). The results also suggested that H. pluvialis reconstructed indigenous and biofilm microbial communities in MBR. The biodegradation network was modified and the relative abundance of Proteobacteria increased, while Firmicutes and Bacteroidetes were significantly reduced. Display omitted •Microalgal addition alleviated biofouling and enhanced antibiotic removal.•Antibiotic degradation was increased by 20% for tetracycline.•Toxic effects of antibiotics on beneficial microbial community were reduced.•Algal-bacterial co-culture was established with genera Pseudomonas and Comamonas.