Scientists Discover Organism That Act Like Living Electrical Wires

Scientists have discovered a new species of electricity-conducting bacteria, Candidatus Electrothrix yaqonensis, in mudflats along Oregon’s Yaquina Bay. This finding has significant implications for environmental cleanup and the development of bioelectronic technologies. The bacterium is part of the cable bacteria group, which form long, filamentous chains capable of conducting electricity through their shared outer membrane.

What makes the new bacteria especially noteworthy is its hybrid genetic makeup. It appears to bridge the gap between two known cable bacteria genera, Ca. Electrothrix and Ca. Electronema, offering potential insights into bacterial evolution. Structurally, it stands out for its pronounced surface ridges and unique nickel-based conductive fibers, which let it transport electrons over long distances. This ability allows the bacterium to participate in redox reactions that are critical for nutrient cycling and pollution breakdown.

Because these bacteria can thrive in diverse environments and conduct electricity without the need for external power, they hold promise for cleaning up contaminated sediments and inspiring new types of bioelectronic devices. The bacterium’s name honors the Indigenous Yaqona people, representing a collaboration between scientists and the Confederated Tribes of Siletz Indians.

Stolen Genes

An article from Science Magazine is posing the question if eukaryotes have had an evolutionary "helping hand" because of their cell nucleus when it comes to genes that are transferred from bacteria. When scientists analyzed the genomes of some red algae, which are single-celled eukaryotes, they found that 1% of the genes came from foreign origins. It is suggested that these genes that were acquired helped them adapt to their environments. Prokaryotes regularly and heavily swap genes within a species and it is suggested that this ability is beneficial to evolution.

I wasn't aware that prokaryotes were capable of swapping genes and would really like to know more about how that works. This article from NCBI talks a little bit about genetic switches. The article stated that the sequencing of the human genome has also suggested that at some point humans may have picked up microbial genes, which I also find very interesting.

How Ribosomes Shape the Proteome

Cells are crowded with macromolecules, which restricts the diffusion of proteins, especially in prokaryotic cells without active transport in the cytoplasm. While examining the relationship between crowding, ionic strength and protein diffusion, University of Groningen biochemists made a fascinating discovery: positively charged proteins stick to the surface of ribosome complexes. This explains why most water-soluble proteins carry an overall negative charge. The speed of movement of proteins inside cells is important; many procedures in biological cells depend on interactions between macromolecules (proteins and nucleic acids) and so on their ability to find each other. One of the professor from the University of Groningen stated that the cell cytoplasm is an active place and this will affect protein and RNA diffusion. His team observed the effects of flocking on diffusion, and found a correlation between protein size and diffusion speed. The team then used three different prokaryotes with increasing ionic strength: “the Gram-negative bacterium Escherichia coli, the Gram-positive Lacto coccus lactis and the extremophile Haloferax volcanii, which lives at very high salt concentrations” (University of Groningen). 

Different variants of Green Fluorescent Protein (GFP) with surface charges were constructed, and then the movement of these GFP variants in the three different cell types. They observed that positively charged proteins would diffuse very slowly then, as the further studies were going on it showed that the positive proteins did not bind to the DNA or the cell membrane but to the ribosome complex. The new and unexpected insight that protein movement is a function of protein charge may explain why it is hard to express some proteins in bacterial systems with low ionic strength.  They concluded that a higher ionic strength reduces the stickiness of positively charged proteins and that could be a valuable insight for the construction of protein expression platforms. A final is that the genomes of several endosymbionts show an abundance of positively charged proteins. They said that they have no explanation of how these organisms are able to deal with slow diffusion and ribosomes being engulfed with positive proteins.

References: 

University of Groningen. (2017, December 6). How ribosomes shape the proteome. ScienceDaily. Retrieved December 8, 2017 from www.sciencedaily.com/releases/2017/12/171206100101.htm

How Ribosomes Shape the Proteom. (2017, December 6). Retrieved December 08, 2017, from http://www.sciencenewsline.com/news/2017120614520040.html

Big Step Towards "Designer" Genes

A group of scientists, compiled from around the world were able to create the first successful gene synthesis in a eukaryotic organism. Up until this point, genes were only able to be synthesized and successfully reproduced in prokaryotic organisms like bacteria. As far as yeast's genetic milestones go, this is the biggest accomplishment since 1996 when yeast's genome was originally mapped. Within the last 7 years, scientists have put together 273,871 base pairs of DNA, which is still shorter than the typical yeast DNA of 316,667 base pairs. They made over 50,000 changes to the DNA, and the yeast not only lived, but reproduced. Researchers hope that this accomplishment will help them synthesize yeast quickly in order to help manufacture medicines for diseases like malaria. This is a great advancement for the field of synthetic biology.

For me, I tend to agree that this is a really great accomplishment, especially because of the potential of synthesizing other eukaryotic cells. For researchers to successfully write in genes, they are able to correct gene mutations and this could greatly help humans, obviously. While I am not a big supporter of "designer babies," where people pick certain physical traits that they want, I do believe that we should use our knowledge to create healthy babies. The potential for this research is unimaginable, and I look forward to learning of further advancements in the field of synthetic biology.

Link for the article: http://www.science20.com/news_articles/synthetic_biology_first_functional_designer_chromosome_in_yeast_synthesized-132812

Link for related: http://discovermagazine.com/2014/jan-feb/23-synthesizing-supply-for-malaria-drug