Bioaugmentation potential of free and formulated 2,6-dichlorobenzamide (BAM) degrading Aminobacter sp. MSH1 in soil, sand and water

Abstract

Pesticides are used extensively worldwide, which has led to the unwanted contamination of soil and water resources. Former use of the herbicide 2,6-dichlorobenzonitrile (dichlobenil) has caused pollution of ground and surface water resources by the stable degradation product 2,6-dichlorobenzamide (BAM) in several parts of Europe, which has resulted in the costly closure of several drinking water wells. One strategy for preventing this in future is bioaugmentation using bacterial degraders. BAM-degrading Aminobacter sp. MSH1 was therefore formulated into dried beads and tests undertaken to establish their potential for use in the remediation of polluted soil, sand and water. The formulation procedure included freeze drying, combined with trehalose addition for cell wall protection, thus ensuring a high amount of viable cells following prolonged storage at room temperature. The beads were round-shaped pellets with a diameter of about 1.25 mm, a dry matter content of approximately 95 % and an average viable cell content of 4.4 × 109 cells/g bead. Formulated MSH1 cells led to a similar, and frequently even faster, BAM mineralisation (20–65 % 14CO2 produced from 14C-labelled BAM) in batch tests conducted with sand, water and different soil moisture contents compared to adding free cells. Furthermore, the beads were easy to handle and had a shelf life of several months.

Current Application of Microencapsulation Technology in Bioremediation of Polluted Groundwater

“…Based on this literature review, microencapsulation technologies with various applied micro-carriers as single or combinations keep producing novel micro-engineered materials offering great potential for more innovations in the future. Such innovations are in particular very beneficial for the treatment for contaminated groundwater [22][23][24][25][26][27][28][29].…”

Phylogenomic Reconstruction and Metabolic Potential of the Genus Aminobacter

“…The genus Aminobacter also includes some unclassified strains with interesting bioremediation properties [ 27 ], namely Aminobacter sp. SR38 and Amininobacter sp.…”

Autochthonous Bioaugmentation-Modified Bacterial Diversity of Phenanthrene Degraders in PAH-Contaminated Wastewater as Revealed by DNA-Stable Isotope Probing

“…8,9 However, the efficacy of BA is variable, since the survival and the PAH-degrading ability of the introduced microorganisms are highly dependent on environmental conditions. 10,11 To overcome these difficulties, autochthonous bioaugmentation (ABA) has been proposed as an alternative method. 12 ABA is defined as a BA technology that uses indigenous degraders at the polluted sites (soil, sediment, and water) with the aim of accelerating and enhancing the biodegradation potential.…”

“…PAHs in a polluted environment can be partially degraded by the autochthonous microbial population via natural attenuation. When indigenous microbes lack the capacity to degrade PAHs, the introduction of PAH degraders isolated from other PAH-contaminated sites, , known as bioaugmentation (BA), is a promising technology to encourage PAH degradation. , However, the efficacy of BA is variable, since the survival and the PAH-degrading ability of the introduced microorganisms are highly dependent on environmental conditions. , To overcome these difficulties, autochthonous bioaugmentation (ABA) has been proposed as an alternative method . ABA is defined as a BA technology that uses indigenous degraders at the polluted sites (soil, sediment, and water) with the aim of accelerating and enhancing the biodegradation potential …”