Depolymerization of chitosan-metal complexes via a solution plasma technique.

Chitosan-metal complexes were depolymerized under acidic conditions using a solution plasma system. Four different types of metal ions, including Ag(+), Zn(2+), Cu(2+), and Fe(3+) ions, were added to the chitosan solution at a metal-to-chitosan molar ratio of 1:8. The depolymerization rate was affected by the types of metal ions that form complexes with chitosan.

Characterization and encapsulation efficiency of rhamnolipid vesicles with cholesterol addition.

The effect of cholesterol on the vesicle formation of a rhamnolipid biosurfactant extracted from the liquid culture of Pseudomonas aeruginosa SP4 was investigated. The rhamnolipid vesicles were prepared in a phosphate-buffer saline (PBS) solution (pH 7.4) at a biosurfactant concentration of 2.

Rhamnolipid biosurfactants: production and their potential in environmental biotechnology.

Certain species of Pseudomonas are able to produce and excrete a heterogeneous mixture of biosurfactants with a glycolipid structure. These are known as rhamnolipids. In the biosynthetic process, rhamnolipid production is governed by both the genetic regulatory system and central metabolic pathways involving fatty acid synthesis, activated sugars and enzymes.

Purification and concentration of a rhamnolipid biosurfactant produced by Pseudomonas aeruginosa SP4 using foam fractionation.

Pseudomonasaeruginosa SP4 was cultivated to produce a rhamnolipid biosurfactant from a nutrient broth with palm oil. The foam fractionation technique in batch mode was used for the recovery of the excreted biosurfactant from the free-cell culture medium. The effects of air flow rate, initial foam height, the pore size of the sintered glass disk, initial liquid volume, and operation time on the process performance were studied.

Solution properties and vesicle formation of rhamnolipid biosurfactants produced by Pseudomonas aeruginosa SP4.

A biosurfactant produced by Pseudomonas aeruginosa strain SP4 was previously reported as a mixture of 11 types of rhamnolipid compounds. Among them, the major component in the biosurfactant was characterized as l-rhamnosyl-3-hydroxydecanoyl-3-hydroxydecanoate, or monorhamnolipid (Rha-C(10)-C(10)). In this present study, solution properties of the biosurfactant were investigated in a phosphate-buffer saline (PBS) solution (pH 7.

Biosurfactant production by Pseudomonas aeruginosa SP4 using sequencing batch reactors: effects of oil loading rate and cycle time.

In this present study, sequencing batch reactors (SBRs) were used for biosurfactant production from Pseudomonasaeruginosa SP4, which was isolated from petroleum-contaminated soil in Thailand. Two identical lab-scale aerobic SBR units were operated at a constant temperature of 37 degrees C, and a mineral medium (MM) with palm oil was used as the culture medium. The effects of oil loading rate (OLR) and cycle time on the biosurfactant production were studied.

Structural and physicochemical characterization of crude biosurfactant produced by Pseudomonas aeruginosa SP4 isolated from petroleum-contaminated soil.

Pseudomonas aeruginosa strain SP4, isolated from petroleum-contaminated soil in Thailand, was used to produce a biosurfactant from a nutrient broth with palm oil as the carbon source. The key components of the crude biosurfactant were fractionated by using HPLC-ELSD technique. With the use of ATR-FTIR spectroscopy, in combination with (1)H NMR and MS analyses, chemical structures of the fractionated components of the crude biosurfactant were identified as rhamnolipid species.