Denitrification by a mixture of bacterial strains derived from an upflow sludge blanket reactor, following entrapment in sol-gel glass

Abstract

Whole cell extracts of a bacterial mixture grown in an upflow sludge blanket reactor used for drinking water denitrification, were successfully entrapped into sol-gel glass, and afterwards air dried. The sol-gel complex was able to reduce sodium nitrate and nitrite solutions. Compared with free whole cell extract, the sol-gel complex required twice as much time for nitrate and nitrite reduction. This study is the first successful attempt to entrap denitrifier reductases for experimental denitrification into sol-gel glass. Denitrifying enzymes entrapped into sol-gel glass matrix, can be used several times without significant loss in specificity, but gradual loss in reactivity occurs, probably due to electron donor depletion.