Applications of Genetically Engineered Microbes (GEMS)

Microbial genetics play an important role in industrial and commercial products.  Despite opposition to the use of genetically modified organisms (GMO) in food products, society does not seem overly concerned about GMO medicines.  Perhaps it is because there are misconceptions about genetics in general.  In the video Genetic Engineering, Part 3: Applications and Issues (2001), Dr. David Cove expresses a layman explanation regarding consuming GMO food products -

"We eat enormous amounts of DNA at every meal. The average meal contains about 150,000 kilometers of DNA. As a diet component, DNA is the same wherever it comes from. So eating DNA itself is not a risk. But would a potato engineered to be nematode resistant still be safe to eat? Plainly, that's something that we can test by giving people the potatoes to eat. But before we take that risk, it's worth remembering that the protein will be produced only in the root and only following infection. So, the protein itself shouldn't be present in the potato tubers" (video transcript)       

The National Health Museum. (1990).
Transfer and Cloning of the Insulin Gene

Insulin – Prior to synthesizing insulin through genetic modification, diabetics with sensitivities to animal byproducts experience adverse side effects after administration of the protein.  Human insulin via genetic engineering is more effective because the microorganisms encoded with the human insulin gene produce human insulin (Madigan, Martinko, Stahl, & Clark, 2012).

Scientists isolate the two insulin chain, using restriction enzymes.  The human insulin DNA clones and combines with bacteria.  The result is a bacteria with human DNA that produces the same result as animal derivatives.

In addition to insulin, scientists use recombinant DNA to produce life saving vaccines.

Project Hope. (2013). Polyvalent vaccine bottle

Vaccines – Vaccines are perhaps the most widely used genetically engineered microorganisms.  Recombinant DNA is the primary method.  Recombinant DNA is as it sounds - a recombining of DNA to produce a desirable outcome.  According to Madigan et al., (2012), “one can delete pathogen genes that encode virulence factors but leave those whose products elicit an immune response, yielding a recombinant, live, attenuated vaccine,” which is harmless to the host in most cases (p. 433).  Recombining DNA is useful in fighting more than one disease at a time.  A polyvalent vaccine is able to immunize against two different diseases, like the fowlpox combining with the Newcastle virus, creating a polyvalent vaccine (Madigen, et al., 2012).  

Lindsey, J. (2014). Mucor miehei

Milk and Cheese – The discovery that a naturally occurring enzyme found in the stomach lining of calves curdled the milk storage producing curds and whey (Fankhauser, D., 2009).  Although this method provides an increase of storage time for milk, its method is inhumane.  Scientists are able to produce a genetically modified version of rennet through microbial genetics.  The microbe responsible for truly vegan cheese products is Mucor miehei.








References:

Fankhauser, D.B., (2009). Rennet making for cheese. Retrieved from http://biology.clc.uc.edu/fankhauser/cheese/rennet/rennet.html

"Genetic Engineering, Part 3: Applications and Issues."Films On Demand. Films Media Group, 2001. Web. 25 Aug. 2014.

Lindsey, J. (2014). Mucor miehei [Photo]. Retrieved from http://en.wikipedia.org/wiki/Mucor#mediaviewer/File:Mucor_spec._-_Lindsey_1a.jpg

Madigan, M., Martinko, J.M., Stahl, D.A., and Clark, D. P. (2012). Brock Biology of Microorganisms (10th ed.). Upper Saddle River, New York: Pearson Education.

Project Hope. (2013). Polyvalent vaccine bottle [Photo]. Retrieved from http://www.projecthope.org/news-blogs/project-hope-merck-vaccinate.html

The National Health Museum. (1990). Transfer and Cloning of the Insulin Gene [Photo]. Retrieved from http://www.accessexcellence.org/RC/VL/GG/transfer_and.php