Dataset describing biodegradation of individual polychlorinated biphenyl congeners (PCBs) by Paraburkholderia xenovorans LB400 in presence and absence of sediment slurry

Abstract

This dataset describes the biodegradation of polychlorinated biphenyl (PCB) congeners by Paraburkholderia xenovorans LB400 in absence and presence of PCB-contaminated sediment slurry, over time [1] . In absence of sediment, PCBs were extracted from aqueous bioreactors by liquid-liquid extraction (LLE) with hexane. In presence of sediment, the extraction method used was a modification of U.S. EPA Method 3545 [3] . Sediment slurry samples were extracted from bioreactors using pressurized fluid extraction (Accelerated Solvent Extractor; Dionex ASE-200) with equal parts acetone and hexane. GC–MS/MS triple quadrapole technology in multiple reaction monitoring mode (MRM) was used for identification and quantification of 209 PCBs as 174 chromatographic peaks. Samples were processed in batches of five along with one method blank per batch. All materials used in sample extraction had either been triple rinsed with solvent (methanol, acetone, and hexane) or combusted overnight at 450 °C to prevent background PCB contamination. Results from the method blanks were used to determine the limit of quantification (LOQ) as the upper limit of the 95% confidence interval (average mass plus two times the standard deviation). PCB congener masses were corrected for surrogate recoveries less than 100%. The PCB concentration dataset was dichotomized at the threshold of the congener specific LOQ. Concentrations of congeners below the LOQ were treated as zero. During analysis, PCB concentration data was filtered to include only congeners belonging to the commercial PCB mixture, Aroclor 1248. LOQ corrected data can inform future experimental design and be reused by other researchers for further analysis and / or interpretive insights.

Aerobic Bioaugmentation to Decrease Polychlorinated Biphenyl (PCB) Emissions from Contaminated Sediments to Air

“…SRM analysis has been previously described. 33 Briefly, the percent recovery of our measured values against the certified values for the 27 PCB congeners reportedly yielded a mean of 96 ± 8%. For the present study, mean and standard deviation percentage recoveries of PCB 14, PCB 65-d5, and PCB 166 in experimental samples (PUF) were 93 ± 15, 86 ± 11, and 91 ± 11%, respectively.…”

“…Information on sediment properties (Table S1), homogenization method, and sediment sampling strategy have been previously described. 33 The average total PCB concentration (∑PCB = sum of 171 congeners) was 6350 ng/g (STD = 312 ng/g, n = 6). The PCB congener profile of Altavista sediment most closely resembled the commercial mixture Aroclor 1248 (Figure 1A).…”

“…55−57 Bacterial Strain and Growth Conditions. P. xenovor-ansLB400 was grown aerobically at room temperature on a platform shaker in 4 L Erlenmeyer flasks containing 2 L K1 medium 33 and solid biphenyl crystals (10 mM; 1.55 g/L) as a sole carbon and energy source until the mid-exponential phase (OD 600 = 1.0). Cells were harvested in 1 L batches by three rounds of centrifugation (5000g, 20 min per round) and washed twice with sterile 20 mM phosphate buffered saline solution and resuspended in K1 medium overnight on a platform shaker.…”

“…Bioreactors were 250 mL Erlenmeyer flasks containing a PCB-contaminated sediment slurry (10% mass to volume ratio; ∼10 g weathered sediment [wet weight] to 100 mL aqueous solution; determined gravimetrically; Figure S3). For appropriate comparison across control and treatment groups, liquid K1 medium 33 was used in the saponin-free control because LB400 cells added to the treatment groups were suspended in K1 medium. Sediment-free controls containing LB400 in K1 medium with and without saponin were also established for comparison in qPCR experiments.…”

“…SPME fibers were retrieved from bioreactors using tweezers as sediment slurry was transferred from the flask to an evaporating dish inside a fume hood. Recovered SPME fiber segments were rinsed with Optima water, wiped dry with a Kimwipe, measured with a ruler, placed in glass GC-vial inserts filled with hexane to facilitate complete PCB desorption from 33 For ease of reference, a condensed profile of individual PCB congeners is shown along the horizontal axis although all 209 congeners (minus surrogate and internal standards) were measured. The condensed profile represents congeners ≥2% of the total profile, by mass fraction, in either PUF or SPME samples at any time point in any treatment.…”