Estudo da produção de cefalosporina C : composição do meio, produtividades especificas e caracterização reologica em processos conduzidos em batelada e batelada alimentada

AUTOR(ES)
DATA DE PUBLICAÇÃO

1998

RESUMO

Bioprocess for cephalosporin C production in fed-batch fermentor was studied concermng medium composition, specific productivity and rheological characterization. The batch process was performed in shake flasks and in 5 liters stirred tank reactor provided with pH, temperature, aeration and agitation control. In the shake flask experiments the performance of the strain Cephalosporium acremonium ATCC 48272, was examined with media containing glucose, fructose and sucrose. The medium with glucose and sucrose at the ratio 27:36 enable the best behavior concerning specific productivity, 0.18 mgcpc/gcél.h. In the runs carried out in stirred tank biorreactor the 27:36 ratio for glucose and sucrose was utilized, while in the fed-batch experiments the effect of different glucose ratios, 81:100; 27:126; 26:187 was examined. The higher specific productivity (0.62 mgcpdgcél.h) was observed for the experiment with 81:100 ratio glucose:sucrose. For the batch process with 27:36 glucose:sacarose ratio, the specific productivity was 0.74 mgcpdgcél.h. The rheological characterization of the mash were made in concentric cylinders viscometer. For each bioprocess it presented Newtonian and pseudoplastic behavior depending on the fermentation time. The consistency index (K) reached its maximum value between 3Oand 40 hours fermentation time, while the flow behavior index (n) showed similar values for all experiments. The photomicrographs taken during the process showed a relationship between the three cell morphologies and the three bioprocess phases: initial phase, glucose depletion phase and cephalosporin C production phase

ASSUNTO(S)

fungos - morfologia fungos - biotecnologia fluidos não newtonianos fungos - cultura e meios de cultura reologia fermentação

ACESSO AO ARTIGO

Documentos Relacionados