title: Optimization of extracellular xylanase production by Sclerotinia sclerotiorum S2 using factorial design.
abstract: The improvement of xylanase production by Sclerotinia sclerotiorum S2 using a liquid fermentation culture was investigated. The optimized process was divided into three basic steps: (i) evaluating xylanase inducers using different agricultural residues such as wheat bran, oat bran, orange peel and barley bran at 1% final concentration, and also filter paper. Among these, wheat bran showed the maximum activity (2.5 U/ml) at 12 days post-inoculation; (ii) for optimization, we determined the optimal concentration of inducer, the effect of phosphate anion (K2HPO4/KH2PO4) and culture aeration using a rotary shaker at 100 and 180 rpm. The optimal conditions for these three factors were determined in an experimental panel using factorial data, in which a mathematical model (Minitab software) was fitted; (iii) The optimized culture medium containing a high level of wheat bran (3%) without KH2PO4-K2HPO4 and submitted to a high agitation (180 rpm/min) increased the xylanase production from 2.5 U/ml to 4 U/ml (1.6-fold).
authors.affiliation: Biological Engineering unit, National Institute of Applied Sciences and Technology (I.N.S.A.T.) BP 676, 1080 Tunis Cedex, Tunisia. Ellouze_olfa@yahoo.fr
authors.forename: Olfa
authors.initials: O
authors.lastname: Ellouze
authors.forename: Sami
authors.initials: S
authors.lastname: Fattouch
authors.forename: Faouzi
authors.initials: F
authors.lastname: Mestiri
authors.forename: Mohamed Radhouen
authors.initials: MR
authors.lastname: Aniba
authors.forename: Mohamed Nejib
authors.initials: MN
authors.lastname: Marzouki
mesh_terms: D000838:Anions / Q000378:metabolism; D001203:Ascomycota / Q000201:enzymology*; D019149:Bioreactors; D003470:Culture Media; D004043:Dietary Fiber / Q000378:metabolism; D043364:Endo-1,4-beta Xylanases / Q000302:isolation & purification / Q000378:metabolism*; D005110:Extracellular Space / Q000378:metabolism*; D005285:Fermentation; D001467:Hordeum / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D010710:Phosphates / Q000378:metabolism; D013223:Statistics as Topic
chemical_list: D000838:Anions; D003470:Culture Media; D004043:Dietary Fiber; D010710:Phosphates; D043364:Endo-1,4-beta Xylanases