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2) Colanic Acid (James)

Assay 2.1: Can the chassis produce colanic acid?


While there are multiple strains of E.coli K12 that can produce colanic acid, it has been noted in the literature that some cannot. It is important that before selecting our K12 chassis, we ensure that it can produce colanic acid. A procedure for this has been prepared in Assay 2.1

Assay 2.1

Assay 2.2: Influence of carbon source on colanic acid production & population growth


Once the glucose in the media has been consumed, the chassis will utilise a secondary carbon source to faciliate the production of colanic acid. Assay 2.2 serves to determine the secondary carbon source that is most suited to colanic acid production.

Assay 2.2

Assay 2.3: Sodium Acetate Encapsulation


The encapsulation of colanic acid coated E.coli with sodium acetate has never been attempted. Theoretically, the highly negativly charged colanic acid coat should act as a nucleation site for Na+ ions in the sodium aceteate solution, but it would be wise to prove this in the lab as quickly as possible.

Since we can induce colanic acid production chemically, Assay 2.3 will provide a quick answer as to whether we need to investigate alternative secondary encapsulation technologies.

Assay 2.3

Assay 2.4: Sodium Acetate Exothermic Crystalisation


Sodium acetate crystalisation is an exothermic reaction (hence the use of sodium acetate in hand warmers). If we want exothermic crystalisation to flip the kill switch, we need to model the heat that is released upon crystalisation.

Assay 2.4

Assay 2.5: Qualitative identification of construct-induced colanic acid production


This assay indicates the successful expression of colanic acid inducing genes.

Assay 2.5

Assay 2.6: Quantitative analysis of construct-induced colanic acid production


This assay faciliates an assessment of the protective effect of differing colanic acid profiles.

Assay 2.6

3) Trehalose (Dave)

Assay 3.1: Production of Trehalose


This assay confirms the production of trehalose.

Assay 3.1

Assay 3.2: Trehalose Functionality


This assay confirms the trehalose functionality.

Assay 3.2


  1. Ionescu M and Belkin S. Simple quantification of bacterial envelope-associated extracellular materials. J Microbiol Methods. 2009 Sep;78(3):302-6. DOI:10.1016/j.mimet.2009.06.020 | PubMed ID:19583986 | HubMed [Measure1]
  2. Navasa N, Rodríguez-Aparicio L, Martínez-Blanco H, Arcos M, and Ferrero MA. Temperature has reciprocal effects on colanic acid and polysialic acid biosynthesis in E. coli K92. Appl Microbiol Biotechnol. 2009 Mar;82(4):721-9. DOI:10.1007/s00253-008-1840-4 | PubMed ID:19139876 | HubMed [Colanic11]
All Medline abstracts: PubMed | HubMed