Abstract:

This dataset contains Chlorophyll a concentrations and bacterial cell counts data for four treatments: Control, WAF, CEWAF and DCEWAF. Also, neutral sugar, uronic acid, and protein concentration in three fractions: colloidal fraction (3 kDa- 0.4 µm), suspended particulate matter (SPM, > 0.4 µm) and sinking marine oil snow or marine snow (MOS/MS). Monosaccharide and amino acid composition in the sinking MOS/MS are also included.

Suggested Citation:

Chen Xu, Saijin Zhang, Morgan Beaver, Peng Lin, Luni Sun, Kathy Schwehr, Laura Bretherton, Peter Santschi, Antonietta Quig. 2017. The microbial EPS production and composition in response to oil and Corexit for COAST, a mesocosm of COASTal water with COASTal microbial concentrate. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7WM1BHX

Publications:

Xu, C., Zhang, S., Beaver, M., Lin, P., Sun, L., Doyle, S. M., … Santschi, P. H. (2018). The role of microbially-mediated exopolymeric substances (EPS) in regulating Macondo oil transport in a mesocosm experiment. Marine Chemistry, 206, 52–61. doi:10.1016/j.marchem.2018.09.005

Xu, C., Lin, P., Zhang, S., Sun, L., Xing, W., Schwehr, K. A., … Santschi, P. H. (2019). The interplay of extracellular polymeric substances and oil/Corexit to affect the petroleum incorporation into sinking marine oil snow in four mesocosms. Science of The Total Environment, 693, 133626. doi:10.1016/j.scitotenv.2019.133626

Purpose:

The estimated oil equivalency, EOE, was to help calculate the oil removal efficiency. The Chla&FvFm&BacterialCellCounts dataset was to show the responses of phytoplankton to the addition of oil and/or Corexit in both growth and photosynthesis efficiency, as well as bacterial responses in growth. The EPSComposition dataset was to show the EPS production and composition in three fractions in each individual treatment. The Monosaccharide&AminoAcid dataset was to show the monosaccharide and amino acid composition in the sinking MOS/MS in each individual treatment, and provide molecular level information.

Data Parameters and Units:

Bulk Chlorophyll a (ug/L), Time (T, hours), Fluorescence (Fv/Fm), Replicate, Average, Standard deviation, Average cell counts (cells/mL), Estimated oil equivalents (mg/L), Polysaccharide (mg/L), Neutral sugars (mg-Glucose/L), Error, Protein (mg-BSA equivalent/L), URA (mg-glucuronic acid equivalent/L), Protein-C/TCHO-C, Exopolymeric substance (EPS production, mg/L), Name, Retention time (min), Area, % area, Height, Concentration in the analyte (uM), Procedure blank corrected, Dilution factor corrected (mg/L), Particle weight (mg), Individual sugar to total particle weight (g-monosaccharide/g-particle), Amino acid (nmol/L), colloidal fraction (3 kDa- 0.4 µm), suspended particulate matter (SPM, > 0.4 µm) and sinking marine oil snow or marine snow (MOS/MS) Treatments: Water accommodated fraction (WAF), Control, Chemically enhanced water accommodated fraction (CWAF/CEWAF), Diluted chemically enhanced water accommodated fraction (DCWAF)

Methods:

Protein content in EPS was measured based on a modified bicinchoninic acid (BCA) method (Smith et al., 1985), using the Pierce BCA protein assay kit (Cat. # 23225), with bovine serum albumin (BSA) as the standard. Carbohydrate concentration was determined by using the anthrone method (Morris, 1948), with glucose as the standard. Uronic acid was estimated by adding sodium borate (75 mM) in concentrated sulfuric acid and m-hydroxydiphenyl, with glucuronic acid as the standard (Hung et al., 2001). The sum of proteins, carbohydrates and uronic acid, which were expressed as the sum of bovine serum albumin (BSA), glucose and glucuronic acid equivalents, was reported as “1% EDTA extractable EPS” for SPM and MS/MOS. Only MS/MOS were analyzed for monosaccharide composition in the present study. 400 µL of the EDTA extractant of the MS/MOS sample was diluted with 500 µL nanopure water and 100 µL 1 N HCl (final HCl concentration: 0.1 N) and sealed in a glass ampoule. The sample was hydrolyzed at 150 °C for 1-hour. After hydrolysis, HCl and water in the sample were removed by a stream of N2 and the sample was reconstituted with 20 µL of dexoy-ribose (500 µM) as internal standard of neutral sugar and 980 µL of nanopure water. Two 100 µL of the resulting mixture were injected, respectively, for the determination of neutral sugars and uronic acids, into the CarboPac PA10-4 mm column (4×250 mm) connected to an electrochemical detector with a gold working electrode, and an ISAAC reference electrode. Two different chromatographic elution conditions were applied which were described previously (Zhang et al., 2008; Xu et al., 2011). The standards used for identifying and quantifying neutral sugars were fucose (Fuc), rhamnose (Rha), arabinose (Ara), galactose (Gal), glucose (Glu), xylose (Xyl), mannose (Man), glucuronic acid (GluAc), and galacturonic acid (GalAc). Water samples were filtered onto GF/F filters and then frozen immediately. The filters were then placed in a DMSO/90% acetone solution (40: 60) at -20 °C in the dark for 24 h. Chlorophyll-a (Chl-a) concentration were determined with a calibrated Turner Designs model 10 AU fluorometer, with a Sigma Chl a standard as the calibrant (Quigg et al., 2011; Zhao and Quigg, 2014). The Fluorescence Induction and Relaxation (FIRe) system (FIRe fluorometer, Satlantic Instruments S/N 2) was used to measure the quantum yield for phytochemistry (Fv/Fm). The fluorescence contributed by petroleum components and other interferences in different treatments were corrected by subtracting the fluorescence of the filtered sample (< 0.45 µm) (Quigg et al., 2011; Zhao and Quigg, 2014). COAST Mesocosm The seawater was collected from the same location as that used in TeCOAST Mesocsom, but was collected on October 17 2015, from 8 kilometers off shore south of Galveston (TX) in the Gulf of Mexico. The salinity was 31. The seawater was processed through a charcoal filter to remove large particles and debris. Four treatments were prepared in triplicate. Control tanks were filled with seawater and a plankton mixture. Water accommodated fraction (WAF) of oil was prepared by mixing 25 mL (5 ml ~ every 30 min for 2.5 hrs) of Macondo surrogate oil into 130 L of seawater then mixing for 12 to 24 hrs (Knap et al. 1986; Knap et al. 2016 in preparation). The WAF was then introduced into the WAF mesocosm tanks and filled to 87 L and mixed. From these WAF tanks 6 L was removed for other experiments and analyses (2L for roller tables, 2 L dark/light, 4 L hydrocarbon analyses). In order to make chemically enhanced water accommodated fraction (CEWAF), Corexit was mixed with oil in a ratio of 1:20 and 25 mL of this mixture (5 ml every 30 min for 2.5 hrs) of surrogate oil plus Corexit was added to 130 L of seawater which was mixed for 8 to 24 hrs prior to being transferred to the mesocosm tanks. The CEWAF was then introduced into the CEWAF mesocosm tanks and filled to 96 L and mixed. From these CEWAF tanks 15 L was removed for other experiments and analyses (9 L for the DCEWAF mesocosms, 2L for roller tables, 2 L dark/light, 4 L hydrocarbon analyses). Diluted CEWAF (DCEWAF) was prepared by mixing 9 L of CEWAF with 78 L of the original seawater for a total volume of 87 L. From these DCEWAF tanks 6 L was removed for other experiments and analyses (2L for roller tables, 2 L dark/light, 4 L hydrocarbon analyses). Plankton (≥63 µm) were collected using a net and transferred into polycarbonate bottles. This concentrated plankton mass was introduced to the tanks and stirred (2 L to each final volume 83 L) immediately prior to starting the experiments. The EOE mean concentration of the three mesocosms for the control, WAF, DCEWAF and CEWAF at the start of the experiments were 0 mg/L, 0.26 mg/L, 2.77 mg/L and 41.5 mg/L, respectively. The EOE mean concentration of the three for the control, WAF, DCEWAF and CEWAF mesocosms after 72 hours were 0 mg/L, 0.06 mg/L, 1.03, and 17.3 mg/L, respectively. Estimated Oil Equivalence (EOE) The estimated oil equivalents (EOE) were determined by fluorescence (Wade et al. 2011) using Macondo surrogate oil as a standard to produce calibration curves at 5 to 7 concentrations. Water samples (5 to 20 ml) were extracted with 5 ml of dichloromethane. An aliquot of the extract was placed in a cuvette for fluorescence analyses (Horiba Scientific Aqualog Fluorometer). The EOE were determined from the calibration curve (Wade et al. 2011). Samples with florescence responses that exceeded the calibration curve were diluted so that their florescence was within the calibration range. Samples were taken at the beginning and end of the experiment and at intervals in between and at the same time point as measurements of other parameters during the experiment.

Provenance and Historical References:

Hung, C.-C.; Santschi, P. H., Spectrophotometric determination of total uronic acids in seawater using cation-exchange separation and pre-concentration by lyophilization. Analytica Chimica Acta 2001, 427, (1), 111-117. Morris, D. L., Quantitative Determination of Carbohydrates with Dreywoods Anthrone Reagent. Science 1948, 107, (2775), 254-255. Quigg, A.; Sylvan, J. B.; Gustafson, A. B.; Fisher, T. R.; Oliver, R. L.; Tozzi, S.; Ammerman, J. W., Going West: Nutrient Limitation of Primary Production in the Northern Gulf of Mexico and the Importance of the Atchafalaya River. Aquatic Geochemistry 2011, 17, (4), 519. Smith, P. K.; Krohn, R. I.; Hermanson, G. T.; Mallia, A. K.; Gartner, F. H.; Provenzano, M. D.; Fujimoto, E. K.; Goeke, N. M.; Olson, B. J.; Klenk, D. C., Measurement of protein using bicinchoninic acid. Analytical Biochemistry 1985, 150, (1), 76-85. Xu, C.; Zhang, S. J.; Chuang, C. Y.; Miller, E. J.; Schwehr, K. A.; Santschi, P. H., Chemical composition and relative hydrophobicity of microbial exopolymeric substances (EPS) isolated by anion exchange chromatography and their actinide-binding affinities. Marine Chemistry 2011, 126, (1-4), 27-36. Zhang, S.; Xu, C.; Santschi, P. H., Chemical composition and Th-234 (IV) binding of extracellular polymeric substances (EPS) produced by the marine diatom Amphora sp. Marine Chemistry 2008, 112, (1-2), 81-92. Zhao, Y.; Quigg, A., Nutrient Limitation in Northern Gulf of Mexico (NGOM): Phytoplankton Communities and Photosynthesis Respond to Nutrient Pulse. PLoS ONE 2014, 9, (2), e88732.

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