Biodegradation of Fishmeal Wastewater by Bacillus thuringiensis and Photosynthetic Bacteria

Abstract

Bacillus thuringiensis (Bt) and purple nonsulfuer photosynthetic bacteria (PSB) are effective in the degradation of nutrients in fishmeal wastewater (FW) in the present study. The Bt was first cultivated in formulation FW, and then FW treated by Bt was further treated by PSB isolates. The Bt spore count reaches up to 3.15x109cell/ml and its sporulation rate achieves 99% after incubation for 72 h at 28±2°C. Under aerobic with light condition with a PSB inoculum: FW ratio of 1:3, the proliferated PSB cells weighs 13.5 g/ l after being incubated for 72 h at 28±2°C. The treatments of FW with Bt followed by PSB significantly reduces the chemical oxygen demand, total protein, total nitrogen, total phosphorus, and salinity. Their total removal rates are 91.1%, 78.8%, 89.6%, 76.3% and 21.0%, respectively. The ammonia nitrogen increases by 46.3% .The rapid nutrient removal and cell proliferation may make Bt and PSB applicable in treating FW to reduce environmental pollution and produce valuable bacteria.