title: Enhanced production of lipase by the thermophilic Geobacillus stearothermophilus strain-5 using statistical experimental designs.
abstract: Statistically based experimental designs were applied to optimize the cultural conditions for the production of a glycerol-inducible lipase from the thermophilic Geobacillus stearothermophilus strain-5. The effect of nineteen culture conditions on enzyme production was evaluated using Plackett-Burman factorial design. Tween 80, K(2)HPO(4), glycerol and glucose were the most significant factors in improving enzyme production. The selected parameters were then further investigated using central composite design to define the optimal process conditions. Maximal enzyme activity (578 U/ml) was reached under the following conditions: glycerol, 2.24% (v/v); Tween 80, 0.76% (v/v); glucose, 0.76% (w/v) and K(2)HPO(4), 0.38% (w/v) which is about five folds the activity in basal medium. A verification experiment was carried out to examine model validation and revealed more than 98% validity.
authors.affiliation: Department of Molecular and Cell Biology, Faculty of Science, University of Jijel, Ouled Aissa, Jijel, Algeria. sifourm@yahoo.fr
authors.forename: Mohamed
authors.initials: M
authors.lastname: Sifour
authors.forename: Taha I
authors.initials: TI
authors.lastname: Zaghloul
authors.forename: Hesham M
authors.initials: HM
authors.lastname: Saeed
authors.forename: Mahmoud M
authors.initials: MM
authors.lastname: Berekaa
authors.forename: Yasser R
authors.initials: YR
authors.lastname: Abdel-Fattah
mesh_terms: D001709:Biotechnology / Q000379:methods*; D003470:Culture Media; D001411:Geobacillus stearothermophilus / Q000201:enzymology* / Q000254:growth & development; D008049:Lipase / Q000096:biosynthesis*; D008066:Lipolysis; D015233:Models, Statistical; D012044:Regression Analysis; D015203:Reproducibility of Results; D013696:Temperature
chemical_list: D003470:Culture Media; D008049:Lipase