Microscopic marine life interacting with oil droplets

Unlocking Ocean Secrets: How Protein and Polysaccharide Ratios Impact Oil Spill Cleanup

Rhea Morgan in Climate & Environment August 2025 • 4 min read.

"Discover the surprising role of microscopic substances in controlling the surface tension of seawater and their potential to revolutionize oil spill response strategies."

The ocean's surface microlayer, a thin interface between the sea and the atmosphere, plays a vital role in regulating gas exchange and climate. This layer is a dynamic environment where both water-soluble and water-repelling substances interact, influencing everything from cloud formation to the distribution of pollutants like oil.

When oil spills occur, understanding how these substances interact becomes crucial. Amphiphilic compounds—those that have both water-loving and water-repelling properties—can either help oil droplets disperse into smaller, more manageable emulsions, or cause them to clump together into larger, more harmful aggregates. This process is heavily influenced by exopolymeric substances (EPS), natural secretions from marine microbes.

New research is shedding light on the specific roles that proteins and polysaccharides, the main components of EPS, play in controlling the surface tension of seawater and, consequently, the fate of oil in marine environments. By understanding these mechanisms, scientists hope to develop more effective strategies for oil spill remediation.

The Protein-Polysaccharide Puzzle: Understanding Surface Tension

Microscopic marine life interacting with oil droplets

The study focuses on exopolymeric substances (EPS), which are natural secretions released by microbes in response to environmental stress. These EPS are largely composed of proteins and polysaccharides, both of which have unique properties that affect how they interact with oil and water.

Researchers conducted experiments using water samples from mesocosms (controlled experimental systems) that simulated different oil spill scenarios. These included:

Control: Seawater without oil or dispersants.
WAF (Water Accommodated Fraction): Seawater mixed with Macondo surrogate oil, similar to the oil from the Deepwater Horizon spill.
CEWAF (Chemically Enhanced WAF): Seawater mixed with oil and the dispersant Corexit.
DCEWAF: A diluted version of CEWAF.

The team measured several key parameters in these samples, including surface tension, chemical composition, and the ratio of proteins to polysaccharides in the EPS. Confocal microscopy was also used to visualize the interactions between these substances at a microscopic level.

The Future of Oil Spill Response: Harnessing Nature's Cleanup Crew

This research provides valuable insights into the complex interactions between oil, dispersants, and natural substances in the marine environment. By further exploring the roles of proteins and polysaccharides in EPS, scientists can potentially develop more environmentally friendly and effective oil spill cleanup strategies that leverage the power of marine microbes.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.marchem.2018.09.003, Alternate LINK

Title: Protein: Polysaccharide Ratio In Exopolymeric Substances Controlling The Surface Tension Of Seawater In The Presence Or Absence Of Surrogate Macondo Oil With And Without Corexit

Subject: Water Science and Technology

Journal: Marine Chemistry

Publisher: Elsevier BV

Authors: Kathleen A. Schwehr, Chen Xu, Meng-Hsuen Chiu, Saijin Zhang, Luni Sun, Peng Lin, Morgan Beaver, Cameron Jackson, Oscar Agueda, Charles Bergen, Wei-Chun Chin, Antonietta Quigg, Peter H. Santschi

Published: 2018-10-01

Everything You Need To Know

What is the ocean's surface microlayer and why is it significant?

The surface microlayer is the interface between the ocean and the atmosphere. It's a dynamic environment where water-soluble and water-repelling substances interact. These interactions are important because they affect the behavior of pollutants, such as oil, and processes like gas exchange, which influences climate.

What are amphiphilic compounds and how do they affect oil spills?

Amphiphilic compounds have both water-loving and water-repelling properties. When an oil spill happens, these compounds can influence whether the oil disperses into smaller, more manageable droplets or clumps together into larger, more harmful aggregates. This behavior is influenced by exopolymeric substances (EPS).

What are exopolymeric substances (EPS) and what role do proteins and polysaccharides play?

Exopolymeric substances (EPS) are natural secretions from marine microbes, primarily composed of proteins and polysaccharides. These components impact how oil and water interact by affecting the surface tension of seawater. The ratio of proteins to polysaccharides in EPS plays a critical role in the fate and behavior of oil in marine environments.

What were the experimental conditions used to study the impact of oil spills?

Researchers studied four experimental conditions. The first was a control using just seawater. The second, WAF (Water Accommodated Fraction), mixed seawater with Macondo surrogate oil. CEWAF (Chemically Enhanced WAF) was the third, which mixed seawater with oil and the dispersant Corexit. The fourth, DCEWAF, was a diluted version of CEWAF. These conditions helped researchers understand how oil, dispersants, and seawater interact.

How might understanding protein and polysaccharide ratios in exopolymeric substances (EPS) improve oil spill response?

Understanding the roles of proteins and polysaccharides in exopolymeric substances (EPS) could lead to the development of more environmentally friendly oil spill cleanup strategies. By harnessing the natural capabilities of marine microbes, future cleanup efforts could be more effective and have a smaller environmental impact.