Abstract:

Nine bacterial isolates (C1, C5, C8, C12, W10, W11, W13a, W14, W20) that grow on oil and Corexit dispersant were isolated from the northern Gulf of Mexico surface water. All isolates were screened for the production of EPS, both protein and carbohydrates, in culture media that contains water accommodated fraction (WAF) of oil, chemically enhanced water accommodated fraction (CEWAF), and Corexit alone. All isolates were also tested for the degradation of oil and production of extracellular enzymes. The residual concentrations of alkanes and PAHs, exoenzyme activity, and carbohydrates and protein components of the EPS were reported.

Suggested Citation:

Manoj Kamalanathan, Kathy Schwehr, Antonietta Quigg. 2018. Production of extracellular polymeric substances (EPS) and hydrocarbon degradation of bacteria isolated from the northern Gulf of Mexico surface water. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N76H4FXF

Publications:

Bacosa, H. P., Kamalanathan, M., Chiu, M.-H., Tsai, S.-M., Sun, L., Labonté, J. M., … Quigg, A. (2018). Extracellular polymeric substances (EPS) producing and oil degrading bacteria isolated from the northern Gulf of Mexico. PLOS ONE, 13(12), e0208406. doi:10.1371/journal.pone.0208406

Purpose:

To isolate oil-degrading and EPS producing bacteria from northern Gulf of Mexico seawater.

Data Parameters and Units:

Isolated_bacteria_genetics.xlsx: Isolate number Genbank Accession number Identity Isolateds_data_GRIIDC.xlsx: alkanes&PAHs: Isolate Residual alkanes (ng/L) enzyme activity: Isolate Enzyme activity (nmoles/hr) protein&carbohydrates: Isolate Protein ratio Carbohydrate ratio WAF=water accomodated fraction CEWAF=chemically enhanced water accommodated fraction Corexit

Methods:

A 50 mL seawater medium containing a final concentration of 200 mg/L of crude oil was inoculated with each bacterial strain at an initial density of 10^6 cells/mL. At end of 4d experiment, we measured the concentration of alkanes and PAHs in sterile control and all inoculated treatments. Activities of five extracellular enzymes were measured on the bacterial isolates after the 4 d incubation. The samples were incubated with the fluorogenic substrates at a final concentration of 0.2 mM followed by incubation at room temperature in the dark for 3 hours. 4-methylumbelliferyl-α-D-glucopyranoside and 4-methylumbelliferyl-β-D-glucopyranoside were used for α- and β- glucosidase respectively, while 4-methylumbelliferyl oleate was used for lipase amino-peptidase and 4-methylumbelliferyl phosphate was used for alkaline phosphatase, and leu-AMC-hydrochloride was used to assay leucine amino-peptidase. The addition of 0.4 M borate buffer solution adjusted at pH 8.0 for 7-amido-4-methylcoumarin (AMC)-tagged substrates and at pH 10.0 for 4-methylumbelliferyl (MUF)-tagged substrates stopped the reactions. Enzyme activity was then measured by fluorescence intensity at excitation/emission wavelengths (nm) of 380/440 (AMC) or 365/448 (MUF) using BioTek Cytation 5 imaging reader controlled by Gen5 (2.09) software. Heated samples were used as blank for these measurements. The protein/carbohydrate ratios are expressed relative to the DNA content.

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