Abstract:

The 2010 Deepwater Horizon oil spill exposed the marine life in the Gulf of Mexico to unprecedented amounts of oil. Determining the response of phytoplankton to the oil spill is crucial to understanding the effects of this event on the marine food-web. In this study, the sensitive diatom (Thalassiosira pseudonana) was exposed to water accommodated fraction of oil (WAF) in an attempt to understand the mechanism of diatom response to this contaminant. Several parameters were ascertained such as absorption coefficient, relative fluorescence, surface area beta carotene, chlorophyll 1, chlorophyll b, chlorophyll c, chlorophyll c1c2, protein content and abundance with proteomics. High-performance liquid chromatography and BioTek CytationTM 5 imaging reader controlled by Gen5 2.09 software (USA) were used to acquire data. It was found that WAF leads to extensive oxidative stress in T. pseudonana, and its poor anti-oxidative abilities resulted in cellular damage, specifically to photosynthetic light harvesting proteins caused by oxidative damage. Overall, this study provides a mechanistic understanding of the varying degree of response demonstrated by diatoms to oil exposure.

Suggested Citation:

Manoj Kamalanathan, Savannah Mapes, Jessica Hillhouse, Noah Claflin, Douglas Campbell, Antonietta Quigg. 2019. How does oil exposure affect centric diatom Thalassiosira pseudonana?. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/BSYXMGD0

Publications:

Kamalanathan, M., Mapes, S., Hillhouse, J., Claflin, N., Leleux, J., Hala, D., & Quigg, A. (2021). Molecular mechanism of oil induced growth inhibition in diatoms using Thalassiosira pseudonana as the model species. Scientific Reports, 11(1). https://doi.org/10.1038/s41598-021-98744-9

Purpose:

To gain a mechanistic understanding behind how oil affects diatoms.

Data Parameters and Units:

Absorption coefficient: m2. mg chl a-1 Amplitude 1: Å Amplitude 2: Å Fv/Fm: relative fluorescence Sigma PSII: Å2 (quanta)-1 NPQ: relative fluorescence ROS: relative ROS per cell malondialdehyde: microM.Cell-1 Beta carotene (HPLC): microgram per cell Chlorophyll 1 (HPLC): microgram per cell Chlorophyll b (HPLC): microgram per cell Chlorophyll c1c2 (HPLC): microgram per cell Diatoxanthin (HPLC): microgram per cell Diadinocanthin (HPLC): microgram per cell Fucoxanthin (HPLC): microgram per cell Chlorophyll a: microgram per cell Chlorophyll b: microgram per cell Chlorophyll c: microgram per cell Carotenoid: microgram per cell Cell volume: micormeterer^3 Surface area: micrometer^2 Proteins: mg per cell Proteomics: abundance

Methods:

The WAF was prepared using CROSERF method as per described in Bretherton et al. 2018. The total of 1000 mL of media was used for each treatment. To prepare one liter of WAF, 400 microliter of Macondo surrogate oil was added. The initial diatoms cell count was 100,000 cells per mL. The Diatom were cultivated in F/2 media at 19 degree C at 12:12 hr light/dark cycle. The medium used to grow the diatom was F/2 media prepared with filtered Gulf of Mexico seawater obtained from NOAA.

Instruments:

A BioTek CytationTM 5 imaging reader controlled by Gen5 2.09 software (USA) was used to acquire data.

Provenance and Historical References:

Bretherton, L., Williams, A., Genzer, J., Hillhouse, J., Kamalanathan, M., Finkel, Z. V., & Quigg, A. (2018). Physiological response of 10 phytoplankton species exposed to macondo oil and the dispersant, Corexit. Journal of Phycology. doi:10.1111/jpy.12625

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