The SynBio Mashup is a weekly review of articles and news related to synthetic biology and metabolic engineering. While we share most of this on our twitter feed, if you need to catch up on this week’s news just read ahead!
Oragenics, a company focusing on the development of antibiotics against infectious disease and probiotics for oral health in humans and animals and Intrexon, a company which has been focusing on building a synthetic biology platform to create biologically based products have been collaborating to generate lantibiotics. Lantibiotics are a new class of peptide antibiotics that are effective in the treatment of antibiotic-resistant bacteria. On July 28, 2015, the companies released positive data in a critical animal study for multiple compounds from Oragenics Mutacin 1140 lantibiotic platform. The compounds were subjected to a standard proof of concept animal model test to determine their efficacy against a clinically relevant C. dfficile infection compared to a standard dose of vancomycin. The new drug candidate achieved a 100% animal survival rate in the trial, while vancomycin only achieved a 33% survival rate and the placebo control had a 0% survival rate.
The results of the trials helped Intrexon’s market cap exceed $6 billion and shares to reach an all time high of greater than $60. Investment analysts at Wunderlich last week valued Intrexon at $70 per share. Investors have high hopes for Intrexon as they now have a solid revenue stream due to their cattle-breeding platform and have various products that are in the works to reach the commercial market.
During a failed startup attempt to create inexpensive cellphone towers in 2012, Rob Rhinehart realized that the food he was eating was not only “too expensive” but “nutritionally inadequate”. He decided to create his own food based only on the necessary nutrients for the human body, which he ordered off the Internet in mostly pill and powder form. The formula, a yellowish-beige liquid was named Soylent after “Soylent Green” – a film from 1973 where people in a dystopian future live off of mysterious wafers that turn out to be made of human flesh.
Rhinehart was able to live off Soylent for more than 30 days and it now constitutes about 90% of his diet. He is now trying to market the product as a complete food replacement for people who do not have the time or the money to consume traditional food. Soylent is now becoming a trend amongst those who drink it and people are manipulating the formula for their own specific needs. Soylent raised over $3 million dollars on the crowdfunding website Tilt, and in January, 2015 it raised $20 million in Series A funding to increase production and decrease costs to under $3 per meal. Rhinehart wants to make food so cheap that “only the rich will cook” and is hoping to use his formula to help solve global hunger.
Rob Rhinehart’s next idea for Soylent is to produce all of the nutrients of the product from bioengineered algae. Soylent partnered with Solazyme to produce algae based oil and in its current formulation 20% of the calories are made from algae. Rhinehart is hoping that algae based production can be a highly cost effective and environmentally friendly method for producing his product.
Gene drive is the practice of “stimulating biased inheritance of particular genes to alter entire populations.” By introducing the same mutation to both chromosomes, “Selfish Genes” quickly spread through populations even if they are not advantageous to the host. Gene drive has recently been demonstrated in both yeast and in Drosophila.
Gene drive brings up bioethics issues because if a mutant strain, the mutation can spread quickly throughout an indigenous population. While this may seem bad, there are certain instances where this might be beneficial. For example, if a mutated strain of mosquitos that cannot carry malaria is released into the wild, it could prevent the transmission of the disease to humans.
As a result of the developments in gene-drive, on July 30th, 2015, the National Academy of Science held the first of several meetings over the next 15 months to find a balance between the positive and possible negative implications of gene-drive. Additionally, on July 30th Dr. Keven Esvelt, a bioengineer at Harvard Medical School and a group of his peers published a paper to define the containment strategies for gene-drive research performed in the lab. Dr. Esvelt is studying CRISPR gene-drive systems in the nematode Caenorhabditis elegan to determine what happens to the population as engineered DNA is passed on through generations. He is also testing ways of revoking the gene from the population if it becomes problematic. As our understanding and control of gene drive increases, it will be interesting to see how regulations evolve to account for this new technology.
Researchers at the University of Illinois at Chicago and Northwestern University have engineered a tethered ribosome. During normal cellular production of protein, there are two ribosomal subunits that come together around an mRNA. After the production of protein, the ribosomal subunits separate and are able to bind to a new mRNA to produce another protein. Until now it was believed that the binding and separating of ribosomal subunits was essential for the production of protein. Ribo-T not only worked effectively in vitro, but it also worked well enough to sustain normal protein production in bacterial cells lacking wild type ribosomes.
With the advent of Ribo-T, scientists will be able to get a better understanding about ribosomal function in vivo and may be able to use Ribo-T to generate unique, functional polymers, biological therapeutics and maybe one-day create non-biological polymers.
A Wyss Institute team, led by Prof. George Church, has engineered new biosensors to enable a much more effective bi-directional communication with bacterial cells. The four biosensors are orthogonal to each other and rely on standardized inducible transcription regulators allowing for the precise control of gene expression.
These new biosensors effectively double the number of well-characterized and available inducible systems and are an invaluable tool for genetic engineering. When coupled with fluorescent readouts they can enable much better screening and significantly speed-up the design-test-build cycle as demonstrated in this paper.