Bioaugmentation of Soil Contaminated with Zinc

Abstract

An experiment described in this work aimed to establish the role of bioaugmentation in minimizing adverse outcomes of loamy sand contamination with zinc. The bioaugmentation was conducted with the use of microbial strains being most resistant to the action of zinc, which were isolated from the soil contaminated with 1250 mg Zn2+ kg−1 dry matter (DM) of soil after 12-month incubation. The soil was inoculated with 4 strains of bacteria (Bacillus licheniformis KT986159.1, Bacillus sp. KF956639.1, Gordonia amicalis KM113029.1, Leifsonia sp. KJ191763.1) and 4 strains of fungi (Penicillium raperi KC797647.1, Penicillium janthinellum AY373921.1, Penicillium glabrum LT558918.1, Trichoderma harzianum LN714612.1). In the case of the non-contaminated soil, a metal dose of 250 mg Zn2+ kg−1 DM of soil contributed to enhanced proliferation and microorganisms and enzymatic activity. In turn, zinc in its highest dose (1250 mg Zn2+ kg−1 DM of soil) evoked adverse effects, which were manifested in reduced numbers and diversity of microorganisms and suppressed activity of soil enzymes. This contamination rate stimulated only the proliferation of fungi, but their ecophysiological diversity was reduced either. The bioaugmentation treatment minimized adverse effects of zinc. Unfortunately, the use of autochthonous microorganisms failed to reduce zinc bioavailability in the soil.