Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Surface Active Agents01:27

Surface Active Agents

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...
Membrane Fluidity01:23

Membrane Fluidity

Cell membranes are composed of phospholipids, proteins, and carbohydrates loosely attached to one another through chemical interactions. Molecules are generally able to move about in the plane of the membrane, giving the membrane its flexible nature called fluidity. Two other features of the membrane contribute to membrane fluidity: the chemical structure of the phospholipids and the presence of cholesterol in the membrane.Fatty acids tails of phospholipids can be either saturated or...
Membrane Fluidity01:26

Membrane Fluidity

Membrane fluidity is explained by the fluid mosaic model of the cell membrane, which describes the plasma membrane structure as a mosaic of components—including phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character.
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
What are Lipids?01:38

What are Lipids?

Overview
What are Lipids?01:31

What are Lipids?

Lipids function as structural components of cellular membranes, in addition to acting as energy reservoirs and signaling molecules. They are thus crucial to all living organisms.  The three biologically important classes of lipids are triglycerides, phospholipids, and steroids.
Non-Polar and Hydrophobic Characteristics of Lipids
Lipids are a structurally and functionally diverse group of hydrocarbons—compounds consisting of carbon and hydrogen atoms. The carbon-carbon and carbon-hydrogen bonds...
Micelles01:30

Micelles

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...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Polyhydroxyalkanoates as multifaceted biopolymers: an eco-friendly alternative to conventional plastics.

RSC advances·2026
Same author

Optimizing rhamnolipid biosynthesis: evaluating predictive methods using <i>Pseudomonas aeruginosa</i> mutants.

Applied and environmental microbiology·2026
Same author

Metabolic Responses of <i>Candida viswanathii</i> on Lipase Production: Influence of Carbon Sources and Culture System.

ACS omega·2026
Same author

Sustainable synthesis of poly-3-hydroxybutyrate by Escherichia coli and Burkholderia sp. cultivated with molasses: production and characterization.

International journal of biological macromolecules·2026
Same author

Two Engineered <i>Bacillus subtilis</i> Surfactin High-Producers: Effects of Culture Medium, and Potential Agricultural and Petrochemical Applications.

Biology·2026
Same author

Integrated production of polyhydroxyalkanoates and rhamnolipids: Insights in cultivation conditions and metabolic engineering.

Journal of biotechnology·2025

Related Experiment Video

Updated: Jun 3, 2026

Fluorescence-Based Measurements of Phosphatidylserine/Phosphatidylinositol 4-Phosphate Exchange Between Membranes
08:49

Fluorescence-Based Measurements of Phosphatidylserine/Phosphatidylinositol 4-Phosphate Exchange Between Membranes

Published on: March 14, 2021

Rhamnolipid emulsifying activity and emulsion stability: pH rules.

Roberta B Lovaglio1, Francisco José dos Santos, Miguel Jafelicci

  • 1UNESP - Universidade Estadual Paulista, Department of Biochemistry and Microbiology, Institute of Biological Sciences, Av. 24-A, 1515 Bela Vista, CEP 13506-900, Rio Claro, SP, Brazil.

Colloids and Surfaces. B, Biointerfaces
|April 2, 2011
PubMed
Summary
This summary is machine-generated.

Rhamnolipids show strong emulsifying power for various oils and hydrocarbons. Their activity is pH-dependent, peaking under alkaline conditions, suggesting they can replace synthetic surfactants like SDS.

More Related Videos

Using the Droplet Transfer Method to Reliably Prepare Giant Unilamellar Vesicles
08:53

Using the Droplet Transfer Method to Reliably Prepare Giant Unilamellar Vesicles

Published on: September 19, 2025

Assembly of Cell Mimicking Supported and Suspended Lipid Bilayer Models for the Study of Molecular Interactions
12:18

Assembly of Cell Mimicking Supported and Suspended Lipid Bilayer Models for the Study of Molecular Interactions

Published on: August 3, 2021

Related Experiment Videos

Last Updated: Jun 3, 2026

Fluorescence-Based Measurements of Phosphatidylserine/Phosphatidylinositol 4-Phosphate Exchange Between Membranes
08:49

Fluorescence-Based Measurements of Phosphatidylserine/Phosphatidylinositol 4-Phosphate Exchange Between Membranes

Published on: March 14, 2021

Using the Droplet Transfer Method to Reliably Prepare Giant Unilamellar Vesicles
08:53

Using the Droplet Transfer Method to Reliably Prepare Giant Unilamellar Vesicles

Published on: September 19, 2025

Assembly of Cell Mimicking Supported and Suspended Lipid Bilayer Models for the Study of Molecular Interactions
12:18

Assembly of Cell Mimicking Supported and Suspended Lipid Bilayer Models for the Study of Molecular Interactions

Published on: August 3, 2021

Area of Science:

  • Biotechnology
  • Surfactant Chemistry
  • Environmental Science

Background:

  • Rhamnolipids are microbial biosurfactants with significant emulsifying properties.
  • Their application as replacements for synthetic surfactants is of industrial interest.
  • Understanding environmental factors influencing rhamnolipid efficacy is crucial.

Purpose of the Study:

  • To evaluate the impact of pH on the emulsifying activity and stability of rhamnolipids.
  • To compare rhamnolipid performance against a chemical surfactant, Sodium dodecyl sulfate (SDS).
  • To assess rhamnolipids' potential in industrial applications involving hydrophobic substrates.

Main Methods:

  • Investigated rhamnolipid emulsifying activity across a pH range of 3 to 9.
  • Tested substrates included benzene, soybean oil, and kerosene.
  • Emulsifying activity after 24 hours (E(24)) was measured and compared to SDS.

Main Results:

  • pH significantly influences rhamnolipid emulsion formation and stability.
  • Peak emulsifying activity for rhamnolipids was observed under alkaline conditions (pH 8).
  • Highest emulsifying activity was recorded with kerosene at pH 8.

Conclusions:

  • Rhamnolipids exhibit optimal emulsifying performance at alkaline pH.
  • These biosurfactants demonstrate potential to substitute synthetic surfactants like SDS.
  • Findings support the use of rhamnolipids in diverse industrial applications.