Friday’s Featured Organism: Vibrio fischeri

Vibrio fischeri


I love all living things (in a total non-hippy way), but it’s clear that I’ve my preferences, and prokaryotes don’t get as much coverage as Eukarya around here usually. So here’s a bacterium, and what’s cooler than a normal bacterium? A bacterium that glows in the dark. Yes, Vibrio fischeri is a gram-negative marine bacterium, widely studied for its bioluminescence. Not only it lights up, but it’s also capable of symbiosis with marine animals like fishes and squids, which use its bioluminescence to their own advantage, and have co-evolved with these bacteria so that it’s easier for the microorganisms to colonize specific organs in their bodies. As far as I know, it’s also used in ecotoxicology studies, probably in part because it should be easier to check the growth of a glowing bacterium than the growth of a non-shiny one.


Awesome microbiologist saves the life of old, fat italian rockstar and gets funds for research

This is absolutely irrelevant to most people, especially non-italian readers, but I’ve just learned that a couple of weeks ago University of Bologna’s professor Davide Zannoni, who was my teacher of General Microbiology last year, contributed to helping old, fat, drug-addicted italian rockstar Vasco Rossi out of an infection which had plagued him for many months. Rossi, remembered for his songs but also for idiotic acts like trying to sue the italian version of Uncyclopedia for defamation, rewarded the effort by donating 75.000 that will fund a 3 years research program on microbial biofilms (I guess he was crying inside a little bit, thinking of how much drug he could have bought for himself instead – but then he did the right thing). Biofilms are a stage in the life cycle of many bacteria during which the single cells stop living an isolated, planktonic life and instead aggregate on a solid surface, creating a complex structure of polysaccharides that keeps them togheter and attached on the substrate, while allowing liquids to flow in and out through various canals. This way not only the colony can stay in a favourable habitat, but it’s also protected by many dangerous substances, including antibiotics and toxic metals. If a biofilm of dangerous bacteria forms in the human body (like it happened on Rossi’s heart), getting rid of it is extremely difficult: only free bacterial cells can be attacked, but the biofilm will persist, and after the treatement it will usually release more free cells in the organism, again and again. Zannoni’s goal is to find a way to inhibit the biochemical communication between bacterial cells, which is the tool bacteria use to regulate the growth and behaviour of a colony as it was a single organism (I’ve already mentioned this ability in an old article). This would disrupt the colony’s capability to coordinate and create biofilms, thus making the destruction of the bacteria much easier. Based on my experience, I can say that Zannoni is a great teacher and microbiologist, and a very intelligent man. I wish him and the other researchers success in their research, and I hope many will follow Vasco Rossi’s example and donate to scientific research, because the world needs it, and my country needs it more than ever.

P.S. The story (in italian, of course) is here.