Average shear rate in three pneumatic bioreactors

Autor(es)

Thomasi, Sergio S. ^[1] ; Cerri, Marcel O. ^[1] ; Badino, Alberto C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Chem Engn, BR-13565905 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Bioprocess and Biosystems Engineering; v. 33, n. 8, p. 979-988, OCT 2010.
• Citações Web of Science: 11

Resumo

A method proposed in recent literature was applied to evaluate the average shear rate ((gamma) over dot(av)) in three pneumatic bioreactors of 5-dm(3) working volume: bubble column, split airlift, and concentric-tube airlift. The volumetric oxygen transfer coefficient (k(L)a) is the appropriate characteristic parameter to assess the average shear rate (gamma) over dot(av) in this methodology. Correlations for (gamma) over dot(av) as a function of superficial gas velocity in the riser region (U(GR)) and rheological fluid properties (consistency index, K, and flow index, n) were obtained for each model of pneumatic bioreactor studied. The (gamma) over dot(av) values estimated by the proposed methodology lay within the range of values calculated by classical correlations. The proposed correlations were utilized to predict the (gamma) over dot(av) during the Streptomyces clavuligerus cultivations carried out at the same specific air flow rate (3.5 vvm) in the different types of pneumatic bioreactors. The lowest values of (gamma) over dot(av) related to the highest values of consistency index (K) were found for the bubble column bioreactor, and the highest values of (gamma) over dot(av) related to the lowest values of K were found for the concentric-tube airlift bioreactor. Intermediate values were found for the split airlift bioreactor. The results showed that high (gamma) over dot(av) values affect the structural health of the mycelia by the rupture of the hipha. (AU)

• Processo FAPESP: 05/55079-4 - Produção e purificação de ácido clavulânico, cefamicina C e outros metabolitos bioativos de Streptomyces
• Beneficiário: Carlos Osamu Hokka
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 08/10432-7 - Avaliação da hidrodinâmica e da transferência de massa e aplicação de sistema reacional pneumático na produção de compostos beta-lactâmicos
• Beneficiário: Marcel Otavio Cerri
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado