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Managing the Nitrogen economy of bacteria

Posted by | February 21, 2021

Principle Investigators: 

  • Martin Buck (Principal Investigator)
  • John Pinney (Co-Investigator)
  • Raymond Alan Dixon (Co-Investigator)
  • Jacob Guy Bundy (Co-Investigator) Philip Simon Poole (Co-Investigator)
  • Patrik R Jones (Co-Investigator)
  • Michael Peter Stumpf (Co-Investigator)
  • Jorg Schumacher (Researcher Co-Investigator)

Associated with:

Imperial College London, United Kingdom (Lead Research Organisation)

Project Summary:

Plant growth is often limited by the availability of a source of combined nitrogen. Low energy input agriculture and biotechnology would benefit from exploiting bacterial nitrogen fixation to supply N for plant growth and fine chemicals production as ammonia.Our systems and synthetic biology expertise in studying the regulation of N economy of the Ecoli and mycobacterial bacteria ( a prior BBSRC LoLa award) now places us in a strong position to engineer nitrogen fixing bacteria such that they give up some of the ammonia produced by the action of bacterial nitrogenase , firstly to the rhizosphere for plant growth and secondly to other N pathways to allow the biochemical synthesis of fine chemicals.

To achieve the above we will implement wet lab and modelling approaches we have developed to establish the systems behavoiur of the E. coli and mycobacteria to nitrogen run out stress. By making use of our bespoke synthetic transcription control systems which uncouple stress signaling from transcription output, detailed metabolic and regulatory protein quantitation and metabolic flux determinations around the conserved N hub comprising the key proteins and associated enzymatic activities (to include:Glutamine Sythetase, PII, GlnK, AmtB, NtrC, GlnD, GlnE, NifA, NifL, N2ase) we will establish the base line systems behaviours of four dioazotrophs: Klebsiella pneumoniae, Azotobacter, Anobena and Azorhrizobium. The choice of these organisms allows a systematic progression from the simple E. coli cousin Kpneumoniae to the more complex life styles and metabolic capabilities of the three other chosen diazotrophs. We will introduce directed changes to the native transcriptional and PTM regulation schemes to achieve ammonia export. We will determine consequences of this engineered export capacity of fitness and competitiveness and the ability to support plant growth via a modified rhizosphere interaction and a photosynthetic coupled N compound production.