Abstract:

Both phytoplankton and bacteria secrete extracellular enzymes actively that help them degrade the complex molecules to provide them simple carbon (sugars) and nitrogen (amino acids) molecules that can be easily assimilated. This process supports bacterial growth on exopolymeric substances (EPS) and helps support their cell division. However, this process does not lead to depletion of EPS, as only a fraction is consumed by bacteria. Due to the sticky nature of the EPS, the newly formed bacteria will tend to adhere to the EPS, and this will lead to the eventual formation and increase in the size of aggregates. To test this, we added DCB (2,6-dichlorobenzonitrile; an inhibitor of polysaccharide production in diatoms) to Thalassiosira pseudonana in the presence and absence of oil. This dataset contains the confocal laser scanning microscopy (CLSM) micrographs depicting the changes in EPS and microbes showing the effects of DCB and WAF. Other related microcosm datasets are available under GRIIDC UDIs R6.x807.000:0022 and R6.x807.000:0027.

Suggested Citation:

Manoj Kamalanathan, Antonietta Quigg. 2018. Microcosm: CLSM micrographs of generation of exopolymeric substances (EPS) by phytoplankton and bacteria with and without polysaccharide inhibitor at various concentrations of WAF. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N79P307C

Publications:

Kamalanathan, M., Chiu, M.-H., Bacosa, H., Schwehr, K., Tsai, S.-M., Doyle, S., … Quigg, A. (2019). Role of Polysaccharides in Diatom Thalassiosira pseudonana and its Associated Bacteria in Hydrocarbon Presence. Plant Physiology, 180(4), 1898–1911. doi:10.1104/pp.19.00301

Purpose:

Fluorescent micrographs depicting the changes in EPS and microbes showing the effects of DCB and WAF.

Data Parameters and Units:

CLSM micrographs for four experiments: (1) control, (2) control and DCB, (3) WAF, and (4) WAF and DCB

Methods:

Thalassiosira pseudonana (CCMP 1335) was obtained from the National Center for Marine Algae and Microbiota (NCMA). The WAF was prepared by adding oil (400 µL.L-1) into sterile f/2 growth media and stirred overnight in the dark. T. pseudonana cultures were inoculated in control f/2 medium (6 × 1000 mL) and WAF medium (6 × 1000 mL) with approximately 2.6 × 104 cells mL−1. DCB solution prepared in Dimethyl sulfoxide (DMSO) was added to half of the both Control and WAF treatments (3 out of 6 × 1000 mL) to obtain a final concentration of 150 µM. T. pseudonana were incubated for 24-h prior to the addition of DCB to allow growth. Samples were fixed with 3.5% formaldehyde and stained with 1 mg.mL-1 aniline blue for 15 mins. The samples were then gravity filtered through 0.2 m black polycarbonate filters and observed under a Leica DM 2000 LED epi-fluorescence microscope (excitation 360 nm, emission 470 nm).

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