Bioaugmentation as a strategy for cleaning up of soils contaminated with aromatic compounds

Abstract

The contamination of soil with aromatic compounds is of particular environmental concern as they exhibit carcinogenic and mutagenic properties. One of the methods of their removal from soil is bioaugmentation, defined as a technique for improvement of the degradative capacity of contaminated areas by introduction of specific competent strains or consortia of microorganisms. The efficiency of bioaugmentation is determined by many abiotic and biotic factors discussed in this paper. The first include chemical structure, concentration and availability of pollutants as well as physico-chemical properties of soil. In turn, among biotic factors the most important is the selection of proper microorganisms that can not only degrade contaminants but can also successfully compete with indigenous microflora. Several strategies are being developed to make augmentation a successful technology particularly in soils without degrading indigenous microorganisms. These approaches involve the use of genetically engineered microorganisms and gene bioaugmentation. The enhancement of bioaugmentation may be also achieved by delivering suitable microorganisms immobilized on various carriers or use of activated soil.

Effect of Mixing Individual Isolates for Bioreduction of Metals in Contaminated Soil

“…Despite non-addition of inoculum to Treatment D, it still indicated that 16.5% of Zn reduction. This might be due to the presence of pre-existing microbes in the leachate-induced soil, and such microbes may have the capacity to reduce or transform portion of heavy metals [8] without prior amendment. Similarly, Treatment A recorded up to 25% reduction, which may be influenced by pH distribution (Fig.…”

Treatment of chromium contaminated soil using bioremediation

“…After 14 days of chromium exposure, the amount of Bacillus subtilis in 15% bacteria addition reactor increased by the time of test period. This case happened because Bacillus subtilis had already adapted and were able to live well enough [15]. The increasing of Bacillus subtilis colonies number occurred at B50 reactor which is had the lowest chromium concentration.…”

Antibiotic and Heavy Metal Tolerance of Some Indigenous Bacteria Isolated From Petroleum Contaminated Soil Sediments with A Study of Their Aromatic Hydrocarbon Degradation Potential

“…effects (Mrozik and Piotrowska-Seget, 2009;Mishra et al, 2010). Because heavy metal and antibiotic resistance genes are often found on the same mobile genetic element, metal pollution often promotes the emergence of antibiotic resistances in exposed organisms, which fact has also a growing concern in natural and clinical settings (Knapp et al, 2011).…”