Transparent Exopolymeric (TEP) and Coomassie Blue Stainable (CSP) particles in the North Atlantic Ocean, using a new dye-binding assay for determination of CSP

• Main Authors: Cisternas-Novoa, Carolina, Lee, Cindy, Engel, Anja
• Format: Conference Object
• Language: unknown
• Published: 2014
• Subjects: North Atlantic
• Online Access: https://oceanrep.geomar.de/id/eprint/23740/

We measured the vertical distribution of TEP and CSP at a site on the Bermuda Rise by staining parallel samples with Alcian Blue and Coomassie Brilliant Blue, during five research cruises in 2012-2013. We used a new spectrophotometric method, analogous to that for TEP, to measure CSP concentration relative to bovine serum albumin (BSA) standard aggregates. The method is based on the linear relationship between CSP concentration and the absorbance of the eluted dye from a CBB-protein complex. TEP concentrations ranged from 23-53 µg XG eqL-1, and decreased with depth. CSP concentration ranged from 2-24 µg BSA eqL-1, and values decreased with depth, but the CSP max was slightly below that of TEP. The CSP and TEP profile shapes and loss rates were different. These differences support the idea that the two particle types have different origins. Either CSP is more labile than TEP, or TEP and CSP are produced at the same depth, but TEP ascends to the surface due to the combination of its buoyancy, and the high TEP to solid ratio found in low productivity regions.