Bioconversion of potato starch wastewater into biofertilizer by Bacillus amyloliquefaciens for improving tea yield

Effluents from potato starch industry possess a high load of starchy materials. 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 A3 was isolated from soil. The isolate A3 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 potato starch wastewater (PW) as substrate for the cultivation of the biofertilizer strain A3. The isolate A3 can grow well using PW as the culture medium. The maximum yield of 2.2 x10(9) CFU/ml of the isolate A3 was reached in 24 h at 36 degrees C, pH 7.5 using the SW 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.