Autoinduction assays

Secondary Carbon Source and Diauxie growth assay

Aims

To generate the diauxie growth curves, as well as normal growth curves for Top-10 for modelling
To determine the best secondary carbon source for optimal growth

Assay

Cells are allowed to grow at 28°C, and their growth ie OD would be monitored using a plate reader, at 600nm, at regular intervals overnight. A plot of OD vs time will be generated. This result is to be fitted to a diauxie growth model. A control with only glucose and no secondary carbon source is used. This control will give us normal growth curves of Top-10 cells.

See protocol for details

Glucose time delay

Aims

Characterise the tunable time duration it takes before GFP expression (M2 activation)

Assay

The cells will be grown until OD= 0.7.

The RFP value will be monitered, although it is the GFP values that are more critical in this assay.

OD and fluorescence data for GFP which can be converted in [http://partsregistry.org/cgi/measurement/new_batch.cgi Specific Promoter Units (SPUs)].

The secondary carbon source will be taken from the previous experiment (see Secondary carbon source selection for CRP promoter)

The IPTG concentrations will be taken from the previous experiment (see Determining concentration of IPTG)

See Glucose time delay for details

Protein production assays

Cellulase Assay

PAH Assay

IPTG effect on growth

Aims

Measure growth rates at 28 degrees Celsius on minimal growth media so that subsequent testing timings etc. can be streamlined
Determine the effect of IPTG toxicity on growth w/o any protein production complications

Assay

Normal cells (without any constructs) will be grown on M9 media until OD=0.7.
IPTG of various concentrations will then be added, and the OD of the cells will be followed over time

See the protocol for more details

Encapsulation assays

Colanic Acid

Aims

Colanic acid biosynthesis is both time consuming and metabolically expensive. If the E.ncapsulator is to be used in an industrial setting, then colanic acid mediated protection must be highly efficient. Protective efficiency can be defined as the percentage increase in fluorescence per µl of colanic acid produced (when compared to control cells). The following assay can be used to elucidate this parameter.