Team:UNITN-Trento

Hi everybody!

Our team is proud to introduce to you B. fruity, a new environment-friendly way to control fruit ripening by exploiting an engineered light-regulated strain of B. subtilis. The system works by synthesizing ethylene or methyl salicylate (MeSA) upon photoinduction.

Ethylene is a plant hormone widely used to ripen fruit. However its synthesis, handling, and storage is expensive and dangerous. In contrast, B. fruity produces ethylene from inexpensive material by hijacking a metabolic intermediate: 2-oxoglutarate. Our system converts this metabolite to ethylene through the activity of an ethylene forming enzyme (EFE) from Pseudomonas syringae.

B. fruity does not just accelerate ripening, but can also slow the process down, when desired, through the incorporation of a methyl salicylate (MeSA) synthesis pathway. MeSA was previously shown to inhibit the ripening of kiwifruit and tomatoes. The explored MeSA pathway builds upon the 2006 MIT iGEM project “Eau de coli”.

As a proof of concept, we engineered E. coli with the above system plus the YF1/FixJ blue light receptor device.

We are hopeful that B. fruity will simplify the process of bringing fresh fruit from the field to the consumer.