A heavy metal-accumulating Citrobacter sp. was grown in carbon-limiting continuous culture in an air-lift fermentor containing raschig rings as support for biofilm development. Planktonic cells from the culture outflow were immobilized in parallel on raschig rings by chemical coupling (silanization)
Cadmium accumulation by immobilized cells of a Citrobacter sp. using various phosphate donors
β Scribed by L. J. Michel; L. E. Macaskie; A. C. R. Dean
- Publisher
- John Wiley and Sons
- Year
- 1986
- Tongue
- English
- Weight
- 833 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0006-3592
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β¦ Synopsis
Immobilized cells of a Cifrobacfer species scavenge cadmium with high efficiency from challenge flows containing CdZ+. Metal uptake by the cells is mediated by a cellbound phosphatase which liberates inorganic phosphate from an organic phosphate to precipitate cadmium as cell-bound metal phosphate. Hitherto glycerol 2-phosphate has served as the phosphate donor, but for an economic large scale process an inexpensive and readily available phosphate donor is required and the use of alkyl phosphates was investigated. This was limited due to interference by the alcohol simultaneously liberated. An alternative, pulsed process is described whereby alkyl phosphate-supplemented main pulses interspersed with short alkyl phosphate-free "recovery" pulses greatly reduced the requirement for glycerol 2-phosphate. Wider aspects of phosphate donor utilization were also investigated to compare this strain of Citrobacter with a strain previously reported to accumulate lead but not cadmium.
π SIMILAR VOLUMES
Polyacrylamide gel-immobilized cells of a Cifrobacter sp. removed cadmium from flows supplemented with glycerol 2-phosphate, the metal uptake mechanism being mediated by the activity of a cell-bound phosphatase that precipitates liberated inorganic phosphate with heavy metals at the cell surface. Th
Heavy metals can be removed from solution via biocrystallization with enzymaticallyliberated inorganic phosphate, according to MichaelisΒ±Menten kinetics, in free whole cells and cells immobilized within polyacrylamide gel in a Β―ow-through reactor. Sulfate is a competitive inhibitor of phosphate rele