This study aimed to enhance the BIX 01294 growth, carotenoid and bacteriochlorophyll production in together with pollution removal in PSB wastewater treatment via the use of different photoperiod. Moreover, this work investigated the mechanism of PSB growth, carotenoid and bacteriochlorophyll production with different light/dark cycles and different light/dark cycle frequencies.
Rhodopseudomonas was a strain isolated from a local pond. The Gene Bank accession number for this PSB is CP001151.1. The cells were cultured in a thermostat shaker (120 r/min, 26–30 °C) using improved RCVBN medium with a light intensity of 2000 lux ( Lu et al., 2013). After 48 h, the cell concentration in the exponential growth stage reached about 6 × 108 CFU·mL−1. Then cells were used for wastewater treatment.
Since one aim of PSB wastewater treatment is to generate valuable biomass in together of pollutant removal, high-concentration-non-hazardous wastewater is preferred. Sugar wastewater is a typical non-hazardous wastewater with high COD and the amount of sugar wastewater is huge. Synthetic sugar wastewater was used in this study (ingredients see Zhou et al., 2015). The concentration of COD, NH4+-N and total phosphate of 6000 mg·L−1, 400 mg·L−1, and 90 mg·L−1, and initial pH of 7.0. The PSB cells were inoculated to the artificial sugar wastewater at a volume ratio of 1:5.