Functions of Bacillus Subtilis BS7.29 in Wasterwater Treatment

Bacillus subtilis (B. subtilis) is a kind of Gram positive bacteria possessing multiple enzyme systems, which might be useful in wastewater treatment. In this paper, in order to confirm whether Bacillus subtilis BS7.29, a novel strain isolated from soil in our previous work, could be applied in the wastewater treatment, its effects on assimilation of ammonium, transformation of nitrite, and degradation of pectin were investigated. The results showed that the content of NH3-N and NO2-N in aquaculture water decreased with time increasing after being treated with B. subtilis BS7.29. Furthermore, when the secretion enzyme extracted from this bacterium was used to treat the paper-making white water, it could reduce CD and turbid it, decrease the size of colloidal substances and promote the deposition. These findings suggested that B. subtilis BS7.29 might be valuable in the wastewater treatment, and contribute to the development of biological purification of industrial effluents.