title: Pyrene biodegradation enhancement potential of lipopeptide biosurfactant produced by Paenibacillus dendritiformis CN5 strain.
abstract: Effect of biosurfactant on biodegradation of pyrene was studied using a microbial consortium predominantly composed of Pseudomonas viridiflava (49.5%) and Pseudomonas nitroreducens (32.5%) in a batch experiment containing lipopeptidic biosurfactant, produced by Paenibacillus dendritiformis CN5 strain, and mineral salt medium. The results showed that the lipopeptide at 600 and 300mgL-1enhanced pyrene degradation to 83.5% and 67% respectively in 24days compared to 16% degradation in its absence. However degradation of pyrene was reduced to 57% as the lipopeptide supplementation was raised to 900mgL-1. This demonstrates that the biodegradation of pyrene was found to increase with an increase in the lipopeptide concentration up to a threshold level. The experimental data were fitted to the logistic kinetic model which provided best fit with a coefficient of determination (R2) values≥0.97. Maximum specific growth rate, μmaxof 0.97 and 0.69d-1were achieved in the 600 and 300mgL-1lipopeptide amendments in comparison to 0.54d-1in the unamended one. The carrying capacity, Xmaxincreased 4.4-fold in 600mgL-1lipopeptide supplemented samples in comparison to its absence. Generally the lipopeptide showed potential application in improving bioremediation of polycyclic aromatic hydrocarbons contaminated environmental media.
authors.affiliation: Water Utilisation and Environmental Engineering Division, Department of Chemical Engineering, University of Pretoria, Pretoria 0002, South Africa.
authors.forename: Fisseha Andualem
authors.initials: FA
authors.lastname: Bezza
authors.affiliation: Water Utilisation and Environmental Engineering Division, Department of Chemical Engineering, University of Pretoria, Pretoria 0002, South Africa. Electronic address: evans.chirwa@up.ac.za.
authors.forename: Evans M Nkhalambayausi
authors.initials: EMN
authors.lastname: Chirwa
mesh_terms: D001673:Biodegradation, Environmental; D004785:Environmental Pollutants / Q000032:analysis* / Q000378:metabolism; D055666:Lipopeptides / Q000096:biosynthesis / Q000737:chemistry*; D059013:Microbial Consortia; D056507:Paenibacillus / Q000378:metabolism*; D011549:Pseudomonas / Q000254:growth & development*; D011721:Pyrenes / Q000032:analysis* / Q000378:metabolism; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D004785:Environmental Pollutants; D055666:Lipopeptides; D011721:Pyrenes; D013501:Surface-Active Agents; C030984:pyrene
keywords: Bioremediation; Biosurfactant; Lipopeptide; PAH; Pyrene; Solubilization