A native biofilm (NBF) bioreactor for monitoring total toxicity in water was developed in this article. Specific objectives include the investigation of (i) the NBF was introduced in toxicity measurement, and (ii) the immobilized microorganisms on carbon fiber felts are adopted for mediator toxicity assay. Culture conditions of NBF with 35 ◦C and 24 h were adopted, and a measuring condition with 45 mM ferricyanide (at pH 7) was optimized. Under the above conditions, NBF bioreactor was successfully employed to assess toxicities of four toxicants. By adopting the NBF, the IC50 values obtained were much lower than that of the single bacterium as the test microorganism. Furthermore, the long-term storage stability was examined. The result showed that the activity of the microorganisms of NBF was found to be roughly the same within 42 days. We confirmed that this NBF combined with mediator toxicity assay may be served as an early warning for affecting public health and avoiding environmental pollution.

Daming Yong, Dangqin Jin, Yajun Fan, Ruihong Yang, Qichao Wu, Jie Tian and Xiaojun Han