Team:UNITN-Trento

Hi everybody!

Our team is proud to introduce to you B. fruity, a new way to control the maturation of climateric and non-climateric fruit by engineering Bacillus subtilis with a light regulated genetic circuit that produces ethylene upon activation of inactive spores.

Ethylene is a plant hormone that is widely used to ripen fruit, such as bananas, kiwi, apples, and others. However, the chemical synthesis of ethylene is expensive and the handling and storage of the molecule is difficult and dangerous. B. fruity solves these problems by producing ethylene from simple, inexpensive starting material by hijacking a natural metabolic intermediate, 2-oxoglutarate from the TCA cycle, and converting this metabolite to ethylene through the activity of EFE (2-oxoglutarate oxygenase/decarboxylase), an enzyme from Pseudomonas syringae.

Moreover, B. fruity does not just accelerate maturation, B. fruity 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 kiwi and tomato. The exploited MeSA pathway builds upon the 2006 MIT iGEM project "Eau de coli".

We plan to build all of the needed pathways in both E. coli and B. subtilis. We are hopeful that B. fruity will simplify the process of bringing fresh fruit from the field to the consumer.