Improvement of biomass production and glucoamylase activity by Candida famata using factorial design.
To improve biomass production and glucoamylase activity (GA) by Candida famata, culture conditions were optimized. A 2(3) full factorial design (FFD) with a response surface model was used to evaluate the effects and interactions of pH (X1 ), time of cultivation (X2 ), and starch concentration (X3 ) on the biomass production and enzyme activity. A total of 16 experiments were conducted toward the construction of an empiric model and a first-order equation. It was found that all factors (X1 , X2 , and X3 ) and their interactions were significant at a certain confidence level (P < 0.05). Using this methodology, the optimum values of the three tested parameters were obtained as follows: pH 6; time of cultivation 24 H and starch concentration 7 g/L, respectively. Our results showed that the starch concentration (X3) has significantly influenced both dependent variables, biomass production and GA of C. famata. Under this optimized medium, the experimental biomass production and GA obtained were 1.8 ± 0.54 g/L and 0.078 ± 0.012 µmol/L/Min, about 1.5- and 1.8-fold, respectively, higher than those in basal medium. The (R(2) ) coefficients obtained were 0.997 and 0.990, indicating an adequate degree of reliability in the model. Approximately 99% of validity of the predicted value was achieved.
Laboratoire de recherche Bioressources, Biologie Intégrative et Valorisation "BIOLIVAL" de l'Institut Supérieur de Biotechnologie de Monastir, Monastir, Tunisia.
Habib
H
Mosbah
Laboratoire de Biochimie et de Génie Enzymatique des Lipases, ENIS, Université de Sfax, Sfax, Tunisia.
Imen
I
Aissa
Laboratoire de recherche Bioressources, Biologie Intégrative et Valorisation "BIOLIVAL" de l'Institut Supérieur de Biotechnologie de Monastir, Monastir, Tunisia.
Nahla
N
Hassad
Laboratoire de recherche Bioressources, Biologie Intégrative et Valorisation "BIOLIVAL" de l'Institut Supérieur de Biotechnologie de Monastir, Monastir, Tunisia.
Dhaker
D
Farh
Laboratoire d'Analyse, de Traitement et de Valorisation des Polluants de l'Environnement et des Produits, Département de Microbiologie, Faculté de Pharmacie  Université de Monastir, Monastir, Tunisia.
Amina
A
Bakhrouf
Laboratoire de recherche Bioressources, Biologie Intégrative et Valorisation "BIOLIVAL" de l'Institut Supérieur de Biotechnologie de Monastir, Monastir, Tunisia.
Sami
S
Achour
D000704:Analysis of Variance; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D002175:Candida / Q000254:growth & development / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D046508:Culture Techniques / Q000379:methods*; D005285:Fermentation; D005087:Glucan 1,4-alpha-Glucosidase / Q000096:biosynthesis* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D013213:Starch / Q000378:metabolism
D003470:Culture Media; D013213:Starch; D005087:Glucan 1,4-alpha-Glucosidase
Candida famata; biomass; full factorial design; glucoamylase; optimization