| 1 | Author
| H. Eikmeier, H. J. Rehm | Requires cookie* | | Title
| Semicontinuous and Continuous Production of Citric Acid with Immobilized Cells of Aspergillus niger  | | | Abstract
| The citric acid excretion of Ca-alginate-immobilized cells of Aspergillus niger in batch culture decreased with a half-time of approximately 19 days. Reactivation of the biocatalysts by regenera tion in growth medium was possible, but it was followed by a submerged sporulation of the fungus, and medium was highly contaminated with free cells. Citric acid production could better be prolonged by semicontinuous cultivation with medium exchange every 7 or 14 days, respective ly. After 32 days the remaining activity in semicontinuous culture was 1.4-fold higher than in comparable batch experiments. Similar improvements were obtained with a continuous process at a dilution rate of 0.125 v/v • d, whereby medium efflux | | |
Reference
| Z. Naturforsch. 42c, 408—413 (1987); received October 1 1986 | | |
Published
| 1987 | | |
Keywords
| Aspergillus niger, Immobilized Cells, Citric Acid, Semicontinuous, Continuous | | |
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| default:Reihe_C/42/ZNC-1987-42c-0408.pdf | | | Identifier
| ZNC-1987-42c-0408 | | | Volume
| 42 | |
2 | Author
| A. A. Gbolade, G. B. Lockwood | Requires cookie* | | Title
| Biotransformation of Monoterpenes by Polyurethane Foam-Immobilized Cells of Petroselinum crispum (Mill) Nyman  | | | Abstract
| Cells o f Petroselinum crispum cv. "Paramount" and "Plain-leaved" immobilized in polyure thane foam retained the biotransformational characteristics o f their freely suspended cells for certain monoterpenic substrates. Immobilized cells o f both cultivars were more efficient than their free cells in isomerizing geraniol into nerol, but less efficient (< 60%) in reducing the alde hydes, citral and citronellal. M aintenance o f the immobilized cells under the condition o f growth limitation did not enhance the efficiency o f the biochemical reactions. Under the same condition, the freely suspended cells o f cult. "Paramount" exhibited higher efficiency (up to 1.6 times) o f biotransformation o f citral when compared to those in sucrose-supplemented me dia. This investigation lends support to the view that the biochemical productivity o f cultured plant cells for especially monoterpenoids may not necessarily be improved upon immobiliza tion. | | |
Reference
| Z. Naturforsch. 45c, 245 (1990); received N ovem ber 24 1989 | | |
Published
| 1990 | | |
Keywords
| Petroselinum, Biotransformation, Immobilized Cells, M onoterpenes, Polyurethane Foam | | |
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| default:Reihe_C/45/ZNC-1990-45c-0245.pdf | | | Identifier
| ZNC-1990-45c-0245 | | | Volume
| 45 | |
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