Skip to main content

Bacterial microcompartment-directed polyphosphate kinase promotes stable polyphosphate accumulation in E. coli

Liang, Mingzhi, Frank, Stefanie, Lünsdorf, Heinrich, Warren, Martin J., Prentice, Michael B (2017) Bacterial microcompartment-directed polyphosphate kinase promotes stable polyphosphate accumulation in E. coli. Biotechnology Journal, 12 (3). p. 1600415. ISSN 1860-6768. (doi:10.1002/biot.201600415) (KAR id:60055)

PDF Author's Accepted Manuscript
Language: English
Download (590kB) Preview
[img]
Preview
Official URL
http://doi.org/10.1002/biot.201600415

Abstract

Processes for the biological removal of phosphate from wastewater rely on temporary manipulation of bacterial polyphosphate levels by phased environmental stimuli. In E. coli polyphosphate levels are controlled via the polyphosphate-synthesizing enzyme polyphosphate kinase (PPK1) and exopolyphosphatases (PPX and GPPA), and are temporarily enhanced by PPK1 overexpression and reduced by PPX overexpression. We hypothesised that partitioning PPK1 from cytoplasmic exopolyphosphatases would increase and stabilise E. coli polyphosphate levels. Partitioning was achieved by co-expression of E. coli PPK1 fused with a microcompartment-targeting sequence and an artificial operon of Citrobacter freundii bacterial microcompartment genes. Encapsulation of targeted PPK1 resulted in persistent phosphate uptake and stably increased cellular polyphosphate levels throughout cell growth and into the stationary phase, while PPK1 overexpression alone produced temporary polyphosphate increase and phosphate uptake. Targeted PPK1 increased polyphosphate in microcompartments 8-fold compared with non-targeted PPK1. Co-expression of PPX polyphosphatase with targeted PPK1 had little effect on elevated cellular polyphosphate levels because microcompartments retained polyphosphate. Co-expression of PPX with non-targeted PPK1 reduced cellular polyphosphate levels. Thus, subcellular compartmentalisation of a polymerising enzyme sequesters metabolic products from competing catabolism by preventing catabolic enzyme access. Specific application of this process to polyphosphate is of potential application for biological phosphate removal.

Item Type: Article
DOI/Identification number: 10.1002/biot.201600415
Subjects: Q Science
Divisions: Faculties > Sciences > School of Biosciences
Depositing User: Sue Davies
Date Deposited: 24 Jan 2017 11:06 UTC
Last Modified: 23 Jan 2020 04:12 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/60055 (The current URI for this page, for reference purposes)
Warren, Martin J.: https://orcid.org/0000-0002-6028-6456
  • Depositors only (login required):

Downloads

Downloads per month over past year