Kinetic measurements for pseudomonas aeruginosa mr01 during biosurfactant production in two-phase system and developing a double-exponential model for viable cell profile

Bagheri Lotfabad, T ; Sharif University of Technology | 2013

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  1. Type of Document: Article
  2. DOI: 10.5829/idosi.wasj.2013.22.06.340
  3. Publisher: 2013
  4. Abstract:
  5. Biosurfactants are microbial substances which influence interfacial tension. The kinetic study was carried out for Pseudomonas aeruginosa MR01 during biosurfactant production in a two-phase liquid-liquid batch fermentation system. The maximum rhamnolipid concentration (Pmax) and the yield of biosurfactant per 1 biomass (YP/X) in a 5-L bioreactor containing soybean oil medium were found to be approximately 20.9 g.L and 3.1 g.g-1, respectively. Previously reported kinetic models in aqueous systems, three-parameter Gompertz, 2 Luedeking-Piret and Mercier equations, demonstrated adequate goodness-of-fit (r >0.9) to kinetic data recorded for biomass growth, nitrate consumption and rhamnolipid formation during fermentation. A double-exponential equation was developed to model time-course data of viable cells reported as colony-forming units (CFUs). 2 This suggested equation could accurately predict the experimental data with r =0.947 and provide a powerful expression to plot microbial cell count pattern. Low values of the standard error of estimate (SEE) and 2 chi-square(x2) confirmed the acceptable level for the accuracy of fit. The 95% confidence intervals for kinetic parameters in all nonlinear models indicated a narrow range simulating the precision of estimation. This kinetic study may work efficiently in the design and scaling-up of the coming aqueous-organic batch bioreactors which are to be applied to the production of biosurfactants
  6. Keywords:
  7. Batch fermentation ; Biosurfactants ; Kinetic behavior ; Modeling ; Two-phase system
  8. Source: World Applied Sciences Journal ; Volume 22, Issue 6 , 2013 , Pages 809-816 ; 18184952 (ISSN)
  9. URL: http://www.idosi.org/wasj/wasj22(6)13/8.pdf