Almy/Bloomwinkel: Catnip plants in Bloom
Genetically engineered yeast can now make the key ingredient of catnip, nepetalactone. Although the chemical repels insects well, catnip plants (Nepeta Cataria) don't have enough to make it commercially viable.
As well as repelling mosquito bites, insect repellents can prevent serious diseases like malaria. DEET, the most commonly used mosquito repellent in the world, is still highly effective and widely used. DEET is becoming less effective in some areas, and alternatives are necessary.
Numerous studies have demonstrated that nepetalactone repels insects better than DEET. Although catnip has been used in many forms as an insect repellent for a long time, it is not feasible to mass produce a cheaper version.
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Vincent Martin and his Canadian colleagues from Concordia University added eight genes to a strain yeast strain, including key enzymes from catnip to create a chemical pathway to nepetalactone.
Martin says that there is still work to be done to increase levels. It is not a major hurdle, I believe.
The problem is that the process can also produce a toxic substance for the yeast. Martin says that other groups have successfully used yeast engineering to create different chemicals.
Researchers are currently in discussions with companies to obtain the necessary investment to further develop and commercialise yeast.
They should also consider whether nepetalactone is an insect repellent and cat attractant. You can walk around with this molecule on your body, and there won't be any mosquitoes. But, all the cats in the neighborhood will be chasing you. Martin admits that he doesn't know. This is something we will have to investigate.
DEET also has its disadvantages. It can dissolve some plastics and cause damage to synthetic clothing and devices like watches and glasses.
Many chemicals that were once only available from plants can now also be made in pots using genetically engineered organisms. Artemisinin, an antimalarial drug, was one of the first.
This approach, according to proponents, is better for the environment than growing many plants just to get one rare chemical. Martin says that if we're going to be using land to grow things, let's grow valuable food rather than molecules.
Reference: bioRxiv, DOI: 10.1101/2021.08.30.458239
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