title: Optimization of gibberellic acid production by immobilized Gibberella fujikuroi mycelium in fluidized bioreactors.
abstract: An orthogonal experimental design L9 (3(4)) was used to investigate effects of temperature, pH, C:N ratio (glucose-C, NH4Cl-N) and concentrations of rice flour on production of gibberellic acid by Gibberella fujikuroi in 3.5 l fluidized bioreactors. The gibberellic acid production in a fluidized bioreactor could reach 3.90 g l(-1), more than 3-times greater than previously reported for submerged and solid fermentations. pH, rice flour concentration and C:N ratio were the factors that most influenced the production of gibberellic acid; pH being the most important. The response surface of gibberellic acid production to changes in pH and C:N ratio or rice flour concentration indicated that greatest production was found with a C:N ratio of 36.8 and pH 5 while the optimum concentration for rice flour was 2 g l(-1) and production increased with increased pH. The effect of temperature on the production of gibberellic acid was also significant and greatest production was at 30 degrees C.
authors.affiliation: Department of Biotechnology and Bioengineering, CINVESTAV-IPN, Mexico D.F., Mexico. eleazar@iqcelaya.itc.mx
authors.forename: E M
authors.initials: EM
authors.lastname: Escamilla
authors.forename: L
authors.initials: L
authors.lastname: Dendooven
authors.forename: I P
authors.initials: IP
authors.lastname: Magaña
authors.forename: R
authors.initials: R
authors.lastname: Parra
authors.forename: M
authors.initials: M
authors.lastname: De la Torre
mesh_terms: D019149:Bioreactors; D001709:Biotechnology / Q000295:instrumentation / Q000379:methods*; D002244:Carbon / Q000737:chemistry; D003470:Culture Media; D005874:Gibberella / Q000378:metabolism*; D005875:Gibberellins / Q000096:biosynthesis*; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D009584:Nitrogen / Q000737:chemistry; D012275:Oryza / Q000378:metabolism; D010937:Plant Growth Regulators / Q000096:biosynthesis*; D013696:Temperature
chemical_list: D003470:Culture Media; D005875:Gibberellins; D010937:Plant Growth Regulators; D002244:Carbon; C007842:gibberellic acid; D005947:Glucose; D009584:Nitrogen