title: Surfactant aided biodegradation of NAPLs by Burkholderia multivorans: comparison between Triton X-100 and rhamnolipid JBR-515.
abstract: Both chemical surfactants and biosurfactants have been effectively used for the degradation of petroleum hydrocarbons. Chemical surfactants are known to enhance biodegradation effectively while activity of biosurfactants is also comparable and they have the additional advantage of being biodegradable. However, the mode of action of chemical surfactants and biosurfactants may vary. This work was conducted to determine the mode of action of Triton X-100 and rhamnolipid JBR-515 by exploring the factors affecting the process of surfactant aided biodegradation of model non aqueous phase liquids (NAPLs) by a naphthalene degrader, Burkholderia multivorans (NG1). Emulsification studies, growth rate and degradation rate studies were conducted and correlated with alteration in cell surface properties including surface hydrophobicity, cell surface charge and cell surface functional groups. Triton X-100 and JBR-515 demonstrated distinct mode of uptake of NAPLs. Triton X-100 enhanced bioavailability by emulsification and supported direct interfacial uptake of model NAPLs by B. multivorans (NG1). Conversely, the biosurfactant rhamnolipid JBR-515 did not demonstrate emulsification of NAPLs and enhanced bioavailability through micellar solubilization. NAPL composition influenced the alteration in the cell surface properties. For both the surfactants, increase in surfactant concentration increased the rate of utilization of aliphatic hydrocarbons from the NAPLs.
authors.affiliation: Centre for Environmental Science and Engineering (CESE), Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
authors.forename: Sagarika
authors.initials: S
authors.lastname: Mohanty
authors.forename: Suparna
authors.initials: S
authors.lastname: Mukherji
mesh_terms: D019117:Burkholderia / Q000378:metabolism*; D045703:Emulsifying Agents / Q000737:chemistry; D006017:Glycolipids / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D017830:Octoxynol / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D045703:Emulsifying Agents; D006017:Glycolipids; D013501:Surface-Active Agents; C418382:rhamnolipid; D017830:Octoxynol