Simultaneous treatment of fruit juice industry wastewater and single-cell protein synthesis using purple non-sulfur bacteria

Abstract Fruit juice industry wastewater is characterized by high chemical oxygen demand (COD) and low pH, which requires extensive energy if treated aerobically can adversely affect aquatic organisms discharged into water bodies without proper treatment. In this study, purple non-sulfur bacteria (PNSB) were employed to recover carbon through photoanaerobic treatment in the form of single-cell protein (SCP) suitable for aquaculture rich carotenoid bacteriochlorophyll photopigments. The efficacy PNSB was investigated using two types wastewaters, citrus (CJW), mixed (MJW) as substrates at different pH conditions (5.0–8.0). 8.0 showed highest COD removal CJW (89 ± 0.1%) 7.0 MJW (94 1%), respectively. biomass yields 0.493 g-VSS·g-COD −1 0.397 MJW. SCP contents 48 1% 40 3%, Pigment analysis revealed that contained carotenoids bacteriochlorophyll. Carotenoids 1354 64 µg·g 1558 218 biomass; 2097 110 3100 614 biomass, microbial population diversity among conditions, with comprising potentially up 51% microbes culture. results demonstrate could be used potential mediators treat fruit wastewater, produce SCP, photopigments simultaneously.