Bio-stimulation with Bacillus subtilis to realize sucrose wastewater one-step treatment and resource recovery by Aerobic Anoxygenic Phototrophic Bacteria

Bacillus subtilis is a typical strain to bio-stimulate the bioactivity of microorganisms. This paper employed Bacillus subtilis to stimulate lab-cultivated photosynthetic bacteria consortium to treat high COD wastewater under lightaerobic condition. The effluent of sucrose wastewater had COD and NH 3 -N of 66.22 and 7.65 mg/L, which satisfied the national discharge standard. Thus, a one-step wastewater treatment was realized. Further, with optimum inoculating ratio of 1/50 Bacillus subtilis , the biomass reached 3247 mg/L. Especially, the protein content, carotenoids and bacteriochlorophyll of biomass was 30 %, 50 %, 75 % higher than that of control. Thus, excellent resource recovery was achieved. Further analysis showed that the catalase activity decreased with the increase of inoculation rate of Bacillus subtilis . As for the bacterial composition, the proportion of Ectothiorhodospiraceae, an identified Aerobic Anoxygenic Phototrophic Bacteria (AAPB), increased to 42 %. This paper provides a novel way to achieve one-step purification and resource recovery for concentrated wastewater.