Fermented whey - an inexpensive feed source for a laboratory scale selenium-bioremediation reactor system inoculated with Thauera selenatis

It is critical that an inexpensive electron-donor/carbon-source be found fo r selenium bioremediation using the selenate-respiring bacterium, Thauera s elenatis. Since acetate is a preferred substrate for growth of this organis m, a method was developed for fermenting the lactose in whey to large amoun ts of acetate. Indigenous whey microorganisms fermented the whey lactose in this manner when grown in continuous culture at a very slow dilution rate (D = 0.05 h(-1)). The successful use of the fermented whey lactose as the c arbon-source/electron-donor feed for a laboratory-scale selenium-bioremedia tion reactor system, inoculated with T. selenatis, treating selenium-contam inated drainage water was also demonstrated. Selenium oxyanions and nitrate were reduced by 98%.