In recent years, the role of benefi

In recent years, the role of beneficial microorganisms in aquatic ecosystems has received increasing attention because of their numerous benefits, including the improvement of water quality, the adjustment of algal boom, and the production of bioactive compounds (e.g., enzymes,hormones and vitamins) associated with microbial growth (Jin et al.,2005; Zhou et al., 2009). Some researchers have inoculated beneficial microorganisms, enriched from natural soils, into bioreactors to enhance the resistance of activated sludge to toxic substances (such as dyes, heavy metals, and surfactants), reduce the excess sludge production in biological wastewater treatment processes, and mitigate the formation of membrane fouling in a submerged membrane bioreactor process (Kim et al., 2014; Chon et al., 2016). In spite of the remarkable advantages, no comprehensive study has yet been conducted to identify the feasibility of beneficial microorganisms in reducing the excess sludge production and enhancing the removal of nutrients.