title: Biomass and carotenoid production in photosynthetic bacteria wastewater treatment: effects of light intensity.
abstract: This study investigated the feasibility of using photosynthetic bacteria (PSB) to produce biomass and carotenoid while treating wastewater. The effects of light intensity on the biomass, carotenoid and bacteriochlorophyll accumulation in together with pollutant removal were studied. Results showed that it was feasible to use PSB to treat wastewater as well as to produce biomass or carotenoid. 2000 lux was an optimal intensity for biomass production and COD removal, and the corresponding values were 2645 mg/L and 94.7%. 8000 lux was an optimal light intensity for carotenoid production (1.455 mg/L). Mechanism analysis displayed that the greater the bacteriochlorophyll and carotenoid were secreted, the lower the light conversion efficiency turned out to be. The highest light conversion efficiency was achieved at 500 lux; the ATP production, biomass production, and COD removal were the highest at 2000 lux, but the bacteriochlorophyll and carotenoid content were the lowest at 2000 lux.
authors.affiliation: School of Environment & Natural Resource, Renmin University of China, 59 Zhongguancun Street, Beijing 100872, China. Electronic address: zqq2012@126.com.
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China. Electronic address: panyue_zhang@bjfu.edu.cn.
authors.forename: Panyue
authors.initials: P
authors.lastname: Zhang
authors.affiliation: School of Environment & Natural Resource, Renmin University of China, 59 Zhongguancun Street, Beijing 100872, China. Electronic address: zgm@ruc.edu.cn.
authors.forename: Guangming
authors.initials: G
authors.lastname: Zhang
mesh_terms: D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D019149:Bioreactors; D002338:Carotenoids / Q000096:biosynthesis*; D002734:Chlorophyll / Q000096:biosynthesis; D008027:Light; D010788:Photosynthesis / Q000502:physiology*; D012241:Rhodopseudomonas / Q000378:metabolism*; D062065:Wastewater / Q000382:microbiology*; D018508:Water Purification / Q000379:methods*
chemical_list: D002338:Carotenoids; D002734:Chlorophyll; D062065:Wastewater
keywords: Light intensity; Photo-protection; Photosynthetic bacteria; Photosynthetic pigments