Anshul Joshi Term Dos Biomedia Report

Making Evolution Make Microbes Make Products


Date Published: January 8, 2015
Website: Scientific American
Link: http://www.scientificamerican.com/podcast/episode/making-evolution-make-microbes-make-products/
Author: Cynthia Graber

Summary: Genetically modified bacteria has already proven its worth by producing products such as insulin for diabetics. However, this bacterial approach has remained somewhat limited to just a few products because of inefficiencies. A research team at Harvard’s Wyss Institute for Biologically Inspired Engineering has devised a solution to this problem by developing a system to get microbes to produce chemicals faster and more efficiently.The system, drawing upon Darwinian principles of evolution and selection, follows these steps:
1) Insert mutations in specific genes relating to the expression of the desired moleculeThe system takes the bacteria through this process repeatedly, eliminating unproductive bacteria every time. Eventually, the end result found was that the microbes that synthesize the chemical of interest do so with 30 times the output of current systems and 1000 times the speed.
2) Tweak the bacteria so genes for antibiotic resistance are only turned on when the desired molecule is created
3) Expose the bacteria to antibiotics so that the bacteria that didn't produce the sought after chemical die

Relevance: This article connects to two of our recent units: Molecular Genetics, and our current unit of Evolution. In Molecular Genetics we learned about bacterial transformation and modification in order to create desirable products. We specifically learned about the use of restriction enzymes to cut desired genetic code and the use of plasmids to inject this code into the bacterium. Specifically, we learned about the insertion of antibiotic resistance genes in the process for killing off non-transformed bacteria. The researchers use a similar process but also only turn it on when the desired molecule is present, similar to operon gene regulation. Second, the researchers used Darwin's Theory of Natural Selection in this by maintaining only the highest producers.