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From 2014hs.igem.org

Lambert high school’s IGem team is working with multiple chemical compounds such as ethylene and chitosan to create a chemical circuit in which fruit ripens and stays ripe longer. This circuit contains two basic pieces, an aerosol ethylene spray whips ripens fruit, and a chitosan based anti-fungal that stops fungi from feeding off the saccharides on the surface, and inside the fruit, which causes rotting. The ethylene is very easy to obtain biologically, because it is the hormone that causes plant growth. This chemical is released when the fruit is ready to be ripened, which can be affected by climate and other different environmental factors. Every fruit reacts to the chemical in the same way, by ripening, but each fruit species begins the process under different concentrations of ethylene. The IGem team is creating an aerosol spray that will test ripening speed of fruit by varying the concentrations of ethylene on different fruits. The second part of the circuit, the chitosan, has proven harder to biologically produce. It is currently produced with chemical intensive process that doesn't always create the correct type of chitosan. Chitosan is a deacetylated form of chitin, a very common organic compound found in cell walls. Chitosan is naturally produced in nature as a food source for many organisms. This is due to the protein chitin deacetylase (CDA) which removes an acetyl group from chitin. Our goals is to extract the CDA gene from the organism Saccharomyces cerevisiae, a very well-known strain of yeast, and express it in E. coli to mass produce the enzyme and create chitosan. Lambert iGem is also planning on creating a BioBrick of the CDA gene for future implications.