Abstract:

The effect of crude oil exposure was monitored by means of radio-labelled tracers, however, to track the physiological changes of phytoplankton, another experiment was run in parallel without radio-labelled tracers. Photosynthetic physiology parameters: chlorophyll a, Fv/Fm (photosynthesis efficiency), relative electron transfer rates (rate of photosynthesis), light harvesting ability, connectivity between photosynthetic units, and sigma (size of the phytoplankton antennae that harvest light) were monitored over short-term (0, 2, 4, and 8 hours) and long-term (0, 24, 48, and 72 hours) experiment.

Suggested Citation:

Kamalanthan, Manoj and Antonietta Quigg. 2020. Microcosm: Flask experiment of phytoplankton-bacteria interaction in a natural community using control and water-accommodated fraction (WAF) treatments; non-radioactive experiment; Imaging FlowCytobot. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-sj41-vw18

Publications:

Kamalanathan, M., Schwehr, K. A., Labonté, J. M., Taylor, C., Bergen, C., Patterson, N., … Quigg, A. (2021). The Interplay of Phototrophic and Heterotrophic Microbes Under Oil Exposure: A Microcosm Study. Frontiers in Microbiology, 12. doi:10.3389/fmicb.2021.675328

Purpose:

To track the physiological changes of phytoplankton, another experiment was run in parallel without radio-labelled tracers and compliment the measurements made in a parallel experiment conducted using radio-tracers.

Data Parameters and Units:

Photosynthetic efficiency: Fv/Fm (relative units); Absorption cross sectional area: σ (Å2 quanta–1); Light harvesting ability: α (µmol electrons/µmol photons); Chlorophyll: Chl (µg/L); Connectivity: ρ (relative units); Relative electron transport rates: rETRmax (µmol electrons/m2/sec)

Methods:

The concentration of oil in Oil A, Oil B, and Oil C at time t=0 was 400 microliters of oil/liter of seawater. Photo-physiological parameters such as maximum quantum yield (Fv/Fm; relative units), relative electron transport rates (rETRmax; µmol electron m-2 s-1), and light harvesting efficiency (α; µmol electrons/µmol photons) were measured on dark acclimated (15 mins) cultures using a Pulse-Amplitude–Modulated Fluorescence System (Phyto-PAM; Walz), operated by the software Phyto-Win (v2.13; Walz). A Fluorescence Induction and Relaxation Fluorometer System (Satlantic) was used to measure functional absorption cross-section area (σPSII; Å2 quanta–1) and Connectivity ρ (relative units) on dark acclimated (15 mins) cultures.

Instruments:

software Phyto-Win (v2.13; Walz); Pulse-Amplitude–Modulated Fluorescence System (Phyto-PAM; Walz)

Provenance and Historical References:

Bretherton, Laura, Alicia Williams, Jennifer Genzer, Jessica Hillhouse, Manoj Kamalanathan, Zoe V. Finkel, and Antonietta Quigg, 2018. Physiological response of 10 phytoplankton species exposed to macondo oil and the dispersant, Corexit. Journal of phycology, 54(3), pp.317-328. doi: 10.1111/jpy.12625 Kamalanathan, Manoj, Meng-Hsuen Chiu, Hernando Bacosa, Kathy Schwehr, Shih-Ming Tsai, Shawn Doyle, Alexandra Yard, Savannah Mapes, Carlos Vasequez, Laura Bretherton, Jason B. Sylvan, Peter Santschi, Wei-Chun Chin, and Antonietta Quigg, 2019. Role of polysaccharides in diatom Thalassiosira pseudonana and its associated bacteria in hydrocarbon presence. Plant physiology, 180(4), pp.1898-1911. doi: 10.1104/pp.19.00301

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