This journal follows the topics discussed in each episode of Caltech Letters: Biosphere
Editors Lev M. Tsypin John A. Ciemniecki Julian M Wagner
W. LINN MONTGOMERY, PEGGY E. POLLAK
In our first episode, we discuss the strange case of the bacterium Epulopiscium fishelsoni, which was first described in detail in this paper. It is a gut symbiont in some surgeon fish, and so bizarre that the authors classified it as a eukaryote. It grows to enormous sizes--sometimes larger than a whopping 600 µm--has elaborate membrane structures, and "gives birth" to live young. It is this latter point that we focus on in this episode. It is not intuitive to think that a microbe would nurture its progeny, but Epulopiscium appears to do just that: the daughter cells mature inside their mother until fully grown, at which point they burst out into the world. How's that for a start to a microbe's life?
The figure above is a phase-contrast micrograph at 1600x magnification, showing the "birth" of two daughters from a mother cell. This is taken from figure 7 in the paper.
We now know that Epulopiscium belongs to the Clostridia, a class of Gram-positive bacteria, but no one has been able to culture them under laboratory conditions, and there remain many unanswered questions. How do they get into the fish guts, and what is their role there? Do they live independent lives somewhere in the environment? How did their unusual lifestyle evolve? In this episode, we touch upon these questions and discuss our own new beginnings as we were starting out as scientists.
The link to this episode is in the header. Get in touch with us on Twitter @BiospherePod and by email at biospherepodcast@gmail.com.