title: Statistical medium optimization and production of a hyperthermostable lipase from Burkholderia cepacia in a bioreactor.
abstract: OBJECTIVE
  Statistical medium optimization for maximum production of a hyperthermostable lipase from Burkholderia cepacia and its validation in a bioreactor.
  
  
  RESULTS
  Burkholderia cepacia was grown in shake flasks containing 1% glucose, 0.1% KH2PO4, 0.5% NH4Cl, 0.24% (NH4)2HPO4, 0.01% MgSO4.7H2O and 1% emulsified palm oil, at 45 degrees C and pH 7.0, agitated at 250 rev min(-1) with 6-h-old inoculum (2% v/v) for 20 h. A fourfold enhancement in lipase production (50 U ml(-1)) and an approximately three fold increase in specific activity (160 U mg(-1)) by B. cepacia was obtained in a 14 litre bioreactor within 15 h after statistical optimization following shake flask culture. The statistical model was obtained using face centred central composite design (FCCCD) with five variables: glucose, palm oil, incubation time, inoculum density and agitation. The model suggested no interactive effect of the five factors, although incubation period, inoculum and carbon concentration were the important variables.
  
  
  CONCLUSIONS
  The maximum lipase production was 50 U ml(-1), with specific activity 160 U mg(-1) protein, in a 14 litre bioreactor after 15 h in a medium obtained after statistical optimization in shake flasks. Further, the model predicted reduction in time for lipase production with reduction in total carbon supply.
  
  
  CONCLUSIONS
  Statistical optimization allows quick optimization of a large number of variables. It also provides a deep insight into the regulatory role of various parameters involved in enzyme production.
authors.affiliation: Department of Microbiology, University of Delhi South Campus, New Delhi, India.
authors.forename: P
authors.initials: P
authors.lastname: Rathi
authors.forename: V K
authors.initials: VK
authors.lastname: Goswami
authors.forename: V
authors.initials: V
authors.lastname: Sahai
authors.forename: R
authors.initials: R
authors.lastname: Gupta
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis*; D019149:Bioreactors; D016956:Burkholderia cepacia / Q000378:metabolism*; D007218:Industrial Microbiology / Q000379:methods*; D008049:Lipase / Q000096:biosynthesis*; D015233:Models, Statistical
chemical_list: D001426:Bacterial Proteins; D008049:Lipase