Enhanced octadecane dispersion and biodegradation by a Pseudomonas rhamnolipid surfactant (biosurfactant)

Journal Article · Thu Oct 01 04:00:00 EDT 1992 · Applied and Environmental Microbiology; (United States)

OSTI ID:7034054

Zhang, Y; Miller, R M ^[1]

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1. Univ. of Arizona, Tucson (United States)

A microbial surfactant (biosurfactant) was investigated for its potential to enhance bioavailability and, hence, the biodegradation of octadecane. The rhamnolipid biosurfactant used in this study was extracted from culture supernantants after growth of Pseudomonas aeruginosa ATCC 9027 in phosphate-limited proteose peptone-glucose-ammonium salts medium. Dispersion of octadecane in aqueous solutions was dramatically enhanced by 300 mg of the rhamnolipid biosurfactant per liter, increasing by a factor of more than 4 orders of magnitude, from 0.009 to >250 mg/liter. The relative enhancement of octadecane dispersion was much greater at low rhamnolipid concentrations than at high concentrations. Rhamnolipid-enhanced octadecane dispersion was found to be dependent on pH and shaking speed. Biodegradation experiments done with an initial octadecane concentration of 1,500 mg/liter showed that 20{percent} of the octadecane was mineralized in 84 h in the presence of 300 mg of rhamnolipid per liter, compared with only 5{percent} octadecane mineralization when no surfactant was present. These results indicate that rhamnolipids may have potential for facilitating the bioremediation of sites contaminated with hydrocarbons having limited water solubility.

• OSTI ID: 7034054
• Journal Information: Applied and Environmental Microbiology; (United States), Journal Name: Applied and Environmental Microbiology; (United States) Vol. 58:10; ISSN 0099-2240; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540320* -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (1990-)
ALKANES
AQUEOUS SOLUTIONS
BACTERIA
BIODEGRADATION
BIOLOGICAL AVAILABILITY
CHEMICAL REACTIONS
CLEANING
DECANE
DECOMPOSITION
DECONTAMINATION
DISPERSIONS
HYDROCARBONS
METABOLISM
MICROORGANISMS
MIXTURES
ORGANIC COMPOUNDS
PH VALUE
PSEUDOMONAS
SOLUTIONS
SURFACTANTS