Utilization of sweet potato starch wastewater for biofertilizer production by Bacillus amyloliquefaciens

摘要

Effluents from the sweet potato starch industry possess a high load of Chemical Oxygen Demand (COD) (10-35 g/1). The treatment of such wastewater by conventional activated sludge processes consumes a lot of energy, resulting in high treatment costs. A plant growth promoting bacterium (PGPB) Bacillus amyloliquefaciens strain EBL 11 was isolated from soil. The isolate EBL 11 performed a good capacity of promoting tea plant growth, which indicated that the strain can be used as a nonchemical alternative biofertilizer. In this study, we investigated the carbon and nutrient rich industrial processing effluents of sweet potato wastewater (SPW) as substrate for the cultivation of the biofertilizer strain EBL 11. The isolate EBL 11 can grow well using SPW as the culture media. The maximum yield of 8.7 × 10~9 CFU/ml of the isolate EBL 11 was reached in 18 h at 32°C, pH 7.0 using the SPW as substrate. In conclusion, it is feasible to develop a hybrid biotechnological process, integrating the production of environmental friendly biofertilizer with treatment of intractable wastewater.