title: Influence of dissolved oxygen and shear conditions on clavulanic acid production by Streptomyces clavuligerus.
abstract: Clavulanic acid (CA), a potent beta-lactamase inhibitor, is produced by a filamentous bacterium. Here, the effect of DO and shear, expressed as impeller tip velocity, on CA production was examined. Cultivations were performed in a 4 L fermentor with speeds of 600, 800 and 1,000 rpm and a fixed air flow rate (0.5 vvm). Also, cultivation with automatic control of dissolved oxygen, at 50% air saturation, by varying stirrer speed and using a mixture of air and O(2) (10% v/v) in the inlet gas, and a cultivation with fixed stirrer speed of 800 rpm and air flow rate of 0.5 vvm, enriched with 10% v/v O(2), were performed. Significant variations in CA titer, CA production rate and O(2) uptake-rate were observed. It was also found that the DO level has no remarkable effect on CA production once a critical level is surpassed. The most significant improvement in CA production was related to high stirrer speeds.
authors.affiliation: Department of Chemical Engineering, Universidade Federal de São Carlos, Cx. Postal 676, CEP 13565-905, São Carlos SP, Brazil.
authors.forename: J C
authors.initials: JC
authors.lastname: Rosa
authors.forename: A
authors.initials: A
authors.lastname: Baptista Neto
authors.forename: C O
authors.initials: CO
authors.lastname: Hokka
authors.forename: A C
authors.initials: AC
authors.lastname: Badino
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000379:methods*; D019818:Clavulanic Acid / Q000096:biosynthesis*; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism*; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism*; D012212:Rheology / Q000379:methods; D033081:Shear Strength; D012995:Solubility; D013302:Streptomyces / Q000254:growth & development / Q000378:metabolism*
chemical_list: D003470:Culture Media; D019818:Clavulanic Acid; D005990:Glycerol; D010100:Oxygen