2024-03-28T08:00:43Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1286212020-07-28T07:00:33Zcom_10261_5063com_10261_5col_10261_5066
00925njm 22002777a 4500
dc
Burgos-Díaz, César
author
Pons Pons, Ramon
author
Teruel, José Antonio
author
Aranda, Francisco José
author
Ortíz, António José
author
Manresa, Ángeles
author
Marqués, Ana María
author
2013-03-01
The commercial application of a new biosurfactant such as the one produced by Sphingobacterium detergens needs a cost-effective process and knowledge of its properties. In the present study, a specific medium and a downstream process have been developed to enhance biosurfactant production. Optimal concentrations of nutrients in MCA medium were (g/L) the following: KH2PO4, 1; K2HPO4, 2; CO(NH2)2 0.88; CaCl2 0.01; FeSO4·7H2O, 0.01; MgSO4·7H2O 0.5; KCl, 1.0; trace elements 0.05mL. Biosurfactant production in the MCA medium required a bacterial co-metabolism of glucose and an n-alkane. A fed-batch culture with supernatant lyophilization prior to organic extraction produced 466mg/L of organic extract, which represents a 6.9-fold increase in production. The newly obtained biosurfactant was a complex mixture of molecules. The three characterized fractions consisted of the complete fraction and two second-level purification fractions with apolar and polar characteristics. The complete and apolar fractions have been shown to self-aggregate in the form of lamellar liquid crystals at a high concentration and bilayers at lower concentrations. Negatively charged particles were identified, which were neutralized at a low pH with a concomitant increase in size. The pH affected the surface tension of the solutions congruently with phosphate headgroups.
Journal of Colloid and Interface Science
http://hdl.handle.net/10261/128621
10.1016/j.jcis.2012.12.017
http://dx.doi.org/10.13039/501100003329
ζ-Potential
CMC
Biosurfactants
Co-metabolism
Lamellar phases
Sphingobacterium detergens
X-ray scattering
The production and physicochemical properties of a biosurfactant mixture obtained from Sphingobacterium detergens