RESUMO
Production of gluconic acid by cells of Aspergillus niger immobilized on polyurethane foam was studied in repeated-batch shake-flask and bubble-column fermentations. For passive immobilization, various amounts of polyurethane foam and spore suspension were tested in order to obtain a suitable combination for optimal concentration of immobilized biomass. Immobilized cells were successfully reused with higher levels of product formation being maintained for longer period (65-70 h) than free cells. The highest gluconic acid concentration of about 143 g l-1 was reached on hydrol-based production medium with 0.3-cm3 foam cubes in the bubble column, where the effect of more suitable aeration and particle volume: medium volume ratio scheme was also investigated.
Assuntos
Aspergillus niger/metabolismo , Gluconatos/metabolismo , Aspergillus niger/ultraestrutura , Biotecnologia , Estudos de Avaliação como Assunto , Fermentação , Microscopia Eletrônica de Varredura , Poliuretanos , Propriedades de SuperfícieRESUMO
Surgical specimens from two patients with simultaneously occurring ovarian and endometrial endometrioid carcinoma were studied by flow cytometry (FCM) and routine histological examination. Tissue derived from the uterine and the ovarian lesion showed similar FCM curves in each case. The information obtained from FCM was more relevant than the study of frozen histological sections as far as confirming or ruling out a common histogenesis was concerned. Study of paraffin sections provided additional data, suggestive of metastatic spread from ovary to uterus in Case 1, and from uterus to ovary in Case 2.