Studies revealing bioremediation potential of the strain Burkholderia sp. GB-01 for abamectin contaminated soils

Abstract

Burkholderia sp. GB-01 strain was used to study different factors affecting its growth for inoculum production and then evaluated for abamectin degradation in soil for optimization under various conditions. The efficiency of abamectin degradation in soil by strain GB-01 was seen to be dependent on soil pH, temperature, initial abamectin concentration, and inoculum size along with inoculation frequency. Induction studies showed that abamectin depletion was faster when degrading cells were induced by pre-exposure to abamectin. Experiments performed with varying concentrations (2-160 mg Kg(-1)) of abamectin-spiked soils showed that strain GB-01 could effectively degrade abamectin over the range of 2-40 mg Kg(-1). The doses used were higher than the recommended dose for an agricultural application of abamectin, taking in account the over-use or spill situations. A cell density of approximately 10(8) viable cells g(-1) dry weight of soil was found to be suitable for bioremediation over a temperature range of 30-35°C and soil pH 7.5-8.5. This is the first report on bacterial degradation of abamectin in soil by a Burkholderia species, and our results indicated that this bacterium may be useful for efficient removal of abamectin from contaminated soils.

Effect of soil fumigants on degradation of abamectin and their combination synergistic effect to root-knot nematode

“…Under different environmental conditions, the degradation rate of ABM was also different [ 23 , 24 ]. Degradation of ABM may be influenced by many factors including the type and quantity of micro-organisms in the soil, the soil characteristics, the incidence of sunlight and rain, the soil pH, the temperature and moisture content [ 45 ].…”

Shifts in taxonomic and functional microbial diversity with agriculture: How fragile is the Brazilian Cerrado?

“…Other groups that are critical for soil functioning and more abundant in agricultural soils were Burkholderales and Nitrosomonadales (Additional file 2 : Figure S2). The Burkholderia are highly versatile in their ecological niches, including agricultural soils [ 39 ], where they play important roles in soil bioremediation [ 10 ], plant growth promotion and biological nitrogen fixation [ 8 , 40 , 41 ]. Nitrogen-fixing Burkholderia are abundantly found in the Cerrado, especially in symbiosis with Mimosa spp., plants that have this biome as their major center of diversity [ 42 ]; in addition, Burkholderia can colonize diverse host plants [ 43 ].…”

“…Soils are the more diverse environment in terms of microorganisms on Earth, with approximately 1,000 Gbp of microbial genome sequences per g of soil [ 4 ]. Microorganisms directly affect the environment and agricultural systems, by means of an array of mechanisms that include biological nitrogen fixation [ 5 ], suppression of diseases [ 6 ], decomposition of organic matter [ 7 ], plant growth promotion [ 8 ], soil nutrient cycling [ 9 ] and bioremediation [ 10 ]. However, soil microbial community structure and its associated biological processes can be readily affected by land use, as a result of changes in soil structure, water holding capacity, temperature fluctuations, organic matter and nutrients contents, pH, introduction of new plant species, and agrichemical inputs (e.g.…”

Phenotypic and phylogenetic characterization of an abamectin-degrading bacterial strain isolated from a citrus orchard

“…Extensive use of abamectin has raised questions about its persistence in the environment and potential toxicity to non-target organisms (Kolar et al, 2008). Keeping in view the importance of pesticide toxicity issues, an abamectin-degrading bacterial strain, GB-01, was isolated from contaminated soil as a potential bioremediation agent and preliminary identified as a Burkholderia cepacia-like species (Ali et al, 2010(Ali et al, , 2012. Keeping in view the problems hampering the identification of a Burkholderia species, the purpose of this study was to conclude the exact classification of strain GB-01, because nomenclature and identification must be based on correct classification and extensive information.…”