The standard construct is a combination of biobricks.
Our construct idea is simple: production of pigment under the regulation of rotten-meat reactive promoter. When the Bacillus subtilis senses the volatiles from the rotten meat, the rotten meat promoter becomes active thus allowing the production of downstream genes. We put pigment genes available downstream of the promoter so that the pigment would be produced when the promoter is activated.
We use our Bacillus subtilis backbone (BBa_K818000) that has sacA and chloramphenicol resistance gene for chromosomal integration and transformants antibiotic screening. This backbone also has E. coli origin of replication, so it can be amplified inside E. coli.
There are several idea to improve our current construct, such as: multi-colored pigment system and fine tuning of the pigment production.