A2: Microbes in the News (#2)

Bacteria in probiotics can evolve in your gut and turn nasty, study shows  (The Independent)

Link: https://www.independent.co.uk/news/health/probiotic-bacteria-gut-health-ibs-bowels-a8840636.html

Summary:  This article talks about a study performed at the University of Washington in Missouri where a probiotic evolved to attack the protective coating of the intestine in the mice they tested. Unhealthy mice with low gut microbial diversity were more likely to develop an evolved strain of the  E. coli Nissle bacteria that was used in the probiotic they studied. According to the researchers, their findings have implications for the development of safer probiotics in the future.

Connections: This article is very relevant to the human microbiome section that we covered in class. It involves the gut microbiome and the ways it can be more or less healthy, and more or less diverse. I think the way microbes can change and evolve right under our noses is fascinating!

Critical analysis: This was certainly an interesting piece and the writing style flowed well. However, this study is only one of many and might mislead readers to think that all probiotics can “turn bad.’ It could also be confusing to the regular reader, because the wording of the article makes it seem like probiotics are drugs that can change inside your body. Of course we all know that probiotics are made up of living bacterial cells that are supposed to help enhance the diversity of your gut microbiome. It was also unclear whether the  E. coli strain always evolved in a negative direction or if it was simply more prone to evolve in an unhealthy gut microbiome (toward good or bad characteristics, we don’t know). Overall, this was a well-written article, but I think the writer conveyed what he wanted the readers to believe and not necessarily the actual truth of the study.

Question:  What were the exact parameters of the evolution of  E. coli Nissle observed in this study?

Microbes in the News

Elusive microbe that consumes ethane found under the sea

Stephen W. Ragsdale                3/27/2019



Summary: In anoxic regions of the ocean a microbe is able to oxidize ethane with the help of its neighbors. Several other species are able to break down methane, propane, and butane. In environments which contain oxygen, using these molecules is thermodynamically favorable. In the absence of oxygen, it is much less favorable, and needs some assistance from other microbes. There is a syntrophy (beneficial to both sides) relationship between the newly discovered ethane eating microbe Candidatus Argoarcheaum ethanivorans and Desulfosarcina which reduces sulfate to sulfide.

Connections: This article discussed some different ways microbes obtain energy. The newly discovered microbe is a methanotroph. Coupling the reaction of one microbe to allow for another microbe to use a unique energy source is not something we covered in class and seems to be a novel idea. We have discussed how the electron tower can predict what microbes use for energy in different environments, however it is cool to learn there are microbes that don’t seem to follow the pattern.

Critical Analysis: It is easy to forget that microbes work together and that each species doesn’t live in a vacuum. The idea that species can transfer molecules and electrons to each other’s benefit is a new idea for me. I was also curious about how we could harness the power of these microbes to break down similar molecular compounds that may cause harm in the environment. I think this story is scientifically accurate because the author explained the controversy between two ideas and provided evidence from research journals to explain each idea. The author talks more about the microbes that break down methane, butane and propane because more is known about them, however it did make it difficult to tell if the author was describing the new microbe or the properties of one already well known.

Question: Can these microbes be used to clean up chemicals and how can we harness the coupled power of microbial metabolism?

3rd Microbes in the News: Bacteria partners with virus to cause chronic wounds

Bacteria partners with  virus to cause chronic wounds

Summary:  The common bacteria, Pseudomonas aeruginosa,  is a  drug-resistant pathogen that causes bacterial infections of those who are immunocompromised. It commonly harbors a bacteriophage, Pf, that occupies the immune response and allows the bacteria to grow at an exponential rate. A vaccine generated by the scientists for the bacteriophage caused a significant decrease in the ability for the bacteria to grow, showing a direct correlation between the bacteriophage/bacteria and how infection can spread because of how Pf and the bacterium working together.

Connections: We have discussed bacteriophages and bacterial infections amongst humans. We have also discussed how bacteria can grow at an exponential rate.

Critical analysis: It is incredible that this was discovered. Amputations are very common amongst diabetic patients with an infected foot ulcer and a vaccine preventing the bacteriophage from infecting the immune cells could help prevent this from being so common in the future. I believe this article is easy to understand and would be easily digestible by the common public.

Question:  Do you think the vaccine could prevent amputations and severe infections in diabetics? Please explain your logic.

2nd Microbes in the News: Bacteria could become a future source of electricity

Bacteria could become a future source of electricity

Source: Lund University – sciencedaily.com

Date: 3/26/2019

Summary:  Obtaining electricity from microbes has been performed in the past, but not very efficiently. There have been new advances in the ability to better harvest the energy produced by bacterial metabolism to try to come up with a reliable, renewable, and sustainable energy source. Enterococcus faecalis  is the bacterial species of focus in this study, a common bacterium found both in human and animal digestive tracts. With the use of a synthetic electrode, termed as a redox polymer, the researchers are able to better harvest electricity through bacterial cell walls.

Connections:  In class, we discussed the ability for bacteria to produce metabolic energy in which they are carrying out redox reactions; metal being the terminal electron acceptor. This is the same concept, but instead of metal being the terminal electron acceptor, the scientists are using an artificial redox polymer to prevent loss of energy in the transfer of electrons.

Critical analysis:  I believe that these scientists are on to something that can benefit our future in terms of utilizing different sources of renewable energy instead of burning fossil fuel. Also, it will help scientists better understand bacteria and how they play a role in their surrounding environment. This article did not give very much information on the methods of this study, but I believe  it is sufficient enough for the common public to understand the concept of what the study is about.

Question:  How long will it take for the world to stop relying on fossil fuels or other toxic sources of energy and to start using eco-friendly renewable sources of energy instead?

Painting With Microbes: Matt Andrews F03 – Exponential Sunrise

Title: Exponential Sunrise

The intention here was to portray a sunrise over water, with the backdrop of the UAF. We live in an exponential world, whether it is as everyday as the light which lets us see, the sounds we hear, the technology which surrounds us, or even the dirt under our fingernails. The world is built on exponential growth and the education we are developing here at the UAF helps us to understand some small part of it.

I had created this scene on sever plates with Micrococcus luteus (for the golden sun and reflection) and Serratia marcescens (for the red water), I was hoping for a bit more color from the Serratia  but I am still happy with the overall effect.

Painting with Microbes

Lab section: F02

I wanted to see what the difference would be using the same bacteria on all three plates.   I used Enterobactor aerogenes for the sun on each plate, Serratia marcescens was used for the birds on each plate and Chromobacterium violaceum was used for the oceans.   Both the Eosin Methylene Blue (EMB) and MacConkey plate select for Gram-negative organisms, while the Trypticase soy agar (TSA) plate is a general growth media.   EMB and MacConkey plates are both differential for lactose fermentation.

All three of the bacteria I used are Gram-negative. As seen from the McConkey plate, S. marcescens, E. aerogenes, and C. violaceum all show lactose fermentation as the entire plate is almost clear.   From the EMB plate we can see that lactose acid has been released during fermentation from the green sheen of   C. violaceum and the dark colors of the other two.

A6: Painting with Microbes

Emily Werner


Escherichia coli- I used this on the EMB agar because it ferments lactose with the specific differential media and creates a green sheen color to it. I thought this would be appropriate for the northern lights.

Enterobacter aerogenes- The color of this microbe is a yellow-white. I used it for the moon and the stars in the photo. The bacteria is anaerobic because it too turned black on the media due to fermentation. I had overlooked that when choosing the bacteria. The stars that I dabbed onto the plate didn’t show up so I’m thinking that there wasn’t enough bacteria present to start a colony or it was still undergoing the lag phase of replication.

Citrobacter freundii-   This was used for the river and the mountains. I wanted to go for a shadow style look for the mountains.


Each bacteria was gram negative so they showed up well on the plate as this agar specifically selects for only gram-negative. The agar was a dark red to begin with but lightened up over the course of 4 days.



Painting with Microbes

Samantha Smith F01

Just a wink and a nudge to my favorite book “East of Eden” by John Steinbeck. I have a a pretty cross stitch of this at home, which admittedly looks a lot better. Perhaps I will stick to my day job and leave the microbe painting to those more artistic than myself.

I used the Eosin Methylene Blue Agar plate for this painting, hoping to achieve a stark different in coloration from the two sources I chose. The lettering and the vine were done with Escherichia coli.  This bacteria is gram negative so is not inhibited by the eosin or methylene blue of the medium. It also produced a deep black color with a metallic green sheen as it ferments lactose with strongly acidic end products. (The green sheen is actually quite pretty, though you can’t tell from the photo). The filigree and leaves are colonies of  Enterobacter aerogenes  which is also gram negative. It produces a pink color because it does ferment lactose, but the end products of fermentation are much less acidic than that of  E. coli.

I would like to add that I had a lot of fun in this assignment and seeing the variety of agar art from the ASM Agar Art Contests.


Painting with Microbes (F03) – Sage Robine

I decided to “paint’ three different flowers for my microbial art. The one pictured above is my favourite. It is drawn on Eosin Methylene Blue (EMB), which selects for gram-negative bacteria. Lactose fermenters (or other fermenters that create acidic products) cause the medium to turn red or black, and may even turn the colonies black. Fermenters that produce less acid turn pink or red, and bacteria that don’t ferment look translucent or pink in colour.

In my case, the medium stayed about the same colour. I used Escheria coli for the center of the flower. It turned a light pink colour, but not black like I expected (since it is a strong lactose fermenter). I used Serratia marcescens for the petals of the flower, which were a very light shade of pink/white (non-fermenter). Enterobacter aerogenes created the circle around the outer edge of the plate and was a beautiful shade of darker pink/purple (fermenter). The black/purple dots were Chromobacterium violaceum which I thought would become more lightly coloured since it is a non-fermenter. The plate looks better in person, since it is easier to see the various shades of pink.