Related Experiment Video
Updated: Apr 3, 2026
13:19
Enhanced Oil Recovery using a Combination of Biosurfactants
Published on: June 3, 2022
6.2K
Surfactin at the Water/Air Interface and in Solution
Javier Iglesias-Fernández1, Leonardo Darré1, Axel Kohlmeyer2
1Department of Chemistry, King's College London , Britannia House, 7 Trinity Street, London SE1 1DB, U.K.
Langmuir : the ACS Journal of Surfaces and Colloids
|September 23, 2015
Summary
Surfactin, a Bacillus subtilis biosurfactant, self-aggregates and exhibits biological activities. Molecular dynamics simulations reveal its solution and interface behavior at different pH values, providing atomistic insights.
Area of Science:
- Biochemistry
- Biophysics
- Materials Science
Background:
- Surfactin is a lipopeptide biosurfactant from Bacillus subtilis with high amphiphilicity and biological activities.
- Biosurfactants offer advantages over synthetic surfactants for biotechnological and biomedical applications.
- Understanding surfactin's aggregation and interfacial behavior is crucial for its applications.
Purpose of the Study:
- To investigate the aggregation properties of surfactin in solution.
- To study surfactin's behavior at the water/air interface.
- To provide atomistic models explaining surfactin's characteristics and action modes at different pH values.
Main Methods:
- Classical molecular dynamics simulations (MD) were employed.
- Simulations were conducted at three distinct pH values.
- MD structural data were validated against experimental neutron reflectivity and volume fraction profiles.
Main Results:
- MD trajectories provided insights into surfactin distribution, conformations, and interactions in solution.
- The behavior of surfactin at the water-air interface was analyzed.
- Atomistic models were developed to rationalize surfactin's structural and dynamic characteristics.
Conclusions:
- The study elucidates surfactin's aggregation and interfacial behavior across different pH conditions.
- Molecular dynamics simulations offer valuable atomistic insights into biosurfactant mechanisms.
- These findings support the rational design and application of surfactin in various fields.
More Related Videos
Related Concept Videos
01:27Surface Active Agents
124
Surfactants, named for their behavior at interfaces, positively adsorb at the interfaces of two phases, reducing interfacial tension. Their versatility as emulsifiers, detergents, and foaming agents stems from this ability. Surfactants, often termed amphiphiles, share the property of amphipathy, with molecules having both hydrophilic and hydrophobic portions. The hydrophilic part is called the head, and the hydrophobic part, including an elongated alkyl substituent, forms the tail.Surfactants...
124
01:18Surface Membrane Barriers
3.4K
The skin and mucous membranes serve as the primary line of defense against pathogens by providing both physical and chemical protection. These barriers are essential in preventing the entry and establishment of microbes, thereby maintaining the integrity of the host.
The outer layer of the skin, the epidermis, is a robust barrier comprising layers of closely packed keratinized cells. This dense arrangement prevents microbes from penetrating the body. The periodic shedding of epidermal cells...
The outer layer of the skin, the epidermis, is a robust barrier comprising layers of closely packed keratinized cells. This dense arrangement prevents microbes from penetrating the body. The periodic shedding of epidermal cells...
3.4K
01:30Micelles
221
Micelle formation is an intricate process that hinges on the properties of amphiphilic or amphipathic molecules and the conditions of the system in which they are found. Amphiphilic molecules, which have both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts, play a critical role in this process.In aqueous environments, these molecules arrange themselves such that their hydrophilic heads are turned towards the water phase, while their hydrophobic tails are oriented away...
221
01:22Surface Tension of Fluid
2.0K
Surface tension is a fundamental property of fluids, occurring at the boundary between a liquid and a gas or between two immiscible liquids. This phenomenon arises from the cohesive forces between molecules at the fluid's surface, creating an effect similar to a stretched elastic membrane. Inside each fluid, molecules are equally attracted in all directions by neighboring molecules, but surface molecules experience a net inward force, resulting in surface tension.
Surface tension varies...
Surface tension varies...
2.0K
03:00Solubility
22.9K
Solution, Solubility, and Solubility Equilibrium
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules,...
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules,...
22.9K
02:57Surface Tension, Capillary Action, and Viscosity
34.6K
Surface Tension
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
34.6K