Ulster University Logo

Ulster Institutional Repository

Isolation of biosurfactant-producing Pseudomonas aeruginosa RS29 from oil-contaminated soil and evaluation of different nitrogen sources in biosurfactant production

Biomedical Sciences Research Institute Computer Science Research Institute Environmental Sciences Research Institute Nanotechnology & Advanced Materials Research Institute

Banat, Ibrahim (2012) Isolation of biosurfactant-producing Pseudomonas aeruginosa RS29 from oil-contaminated soil and evaluation of different nitrogen sources in biosurfactant production. Annals of Microbiology, 62 . pp. 753-763. [Journal article]

[img]
Preview
PDF
392Kb

Abstract

An efficient biosurfactant-producing native Pseudomonas aeruginosa RS29 has been isolated from crude oil contaminated soil. Isolation was followed by optimization of different factors to achieve maximum production of biosurfactant in terms of surface tension reduction (STR) and emulsification index (E24). The isolated strain produced highest biosurfactant in the presence of glycerol after 48 h of incubation at 37.5°C, with pH range of 7–8 and at salinity <0.8% (w/v). The extent of STR and the E24 of medium with different nitrogen sources were investigated and found to be maximal for sodium nitrate (26.3 mN/m, E24=80%) and potassium nitrate (26.4 mN/m, E24=79%). The production of biomass by the designated strain was found to be maximal in ammonium-nitrate-containing medium as compared to the other nitrogen sources. Akinetic study revealed that biosurfactant production is positively correlated with growth of P. aeruginosa, and highest STR was achieved (27.0 mN/m) after 44 h of growth. The biosurfactant was produced as a primary metabolite and 6 g/L crude biosurfactant was extracted by chloroform:methanol (2:1). The critical micelle concentration of the biosurfactant was 90 mg/L. The absorption bands of the FTIR spectra confirmed the rhamnolipid nature of the biosurfactant. The biosurfactant was thermostable (up to 121°C for 15 min) and could withstand a wide range of pH (2–10) and NaCl concentration (2%–10% w/v). The extracted biosurfactant had good foaming and emulsifying activities and was of satisfactory quality in terms of stability (temperature, pH and salinity) and foaming activity.

Item Type:Journal article
Faculties and Schools:Faculty of Life and Health Sciences
Faculty of Life and Health Sciences > School of Biomedical Sciences
Research Institutes and Groups:Biomedical Sciences Research Institute
Biomedical Sciences Research Institute > Pharmaceutical Science and Practice
ID Code:23386
Deposited By:Professor Ibrahim Banat
Deposited On:17 Sep 2012 15:23
Last Modified:17 Sep 2012 15:23

Repository Staff Only: item control page