These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Engineering polyphosphate metabolism in Escherichia coli: implications for bioremediation of inorganic contaminants.
    Author: Keasling JD, Van Dien SJ, Pramanik J.
    Journal: Biotechnol Bioeng; ; 58(2-3):231-9. PubMed ID: 10191394.
    Abstract:
    Polyphosphate metabolism plays an important role in the bioremediation of phosphate contamination in municipal wastewater, and may play a key role in heavy metal tolerance and bioremediation. However, little is known about the regulation of polyphosphate metabolism in microorganisms and its role in heavy metal toxicity. We have manipulated polyphosphate metabolism in Escherichia coli by overexpressing the genes for polyphosphate kinase (ppk) and for polyphosphatase (ppx) under control of their native promoters and inducible promoters. Overexpression of ppk results in high levels of intracellular polyphosphate, improved phosphate uptake, but no increase in tolerance to heavy metals. Overexpression of both ppk and ppx results in lower levels of intracellular polyphosphate, secretion of phosphate from the cell, and increased tolerance to heavy metals. Metabolic flux analysis indicates that the cell responds to increased flux through the PPK-PPX pathway by altering flux through the TCA cycle.
    [Abstract] [Full Text] [Related] [New Search]