Friday, February 14, 2014

A Bioluminescent Valentine's Day!

I was pleased and flattered that the wise and elegant Moselio Schaechter, of the American Society for Microbiology sponsored "Small Things Considered," listed this blog as favored reading recentlyElio, if you are reading this, I continue to be amazed at how well you keep up with the dizzing pace of Matters Microbial™; I think you remain one of my Microbial Heroes™, as Jon Eisen describes them!

Elios's kind words reminded me that I should post more frequently, since some people are reading my essays! 

Even though many of my colleagues at large educational institutions have much larger classes than I do, my current freshman "Unity of Life" course has 48 students (all of them in lecture three days a week, and three lab sections of 16 each during the week) and certainly keeps me jumping. The students come from a wide variety of backgrounds, ranging from business to exercise science to psychology to biology.  It is thus a moving target pedagogically,  especially as I move into the more challenging areas of biochemistry and metabolism. 

However, I cannot let today's holiday pass unnoticed.  To be sure, I am a microbiologist and geneticist, but a romantic heart beats inside me just the same. Thus, I would like to share with you some of my "bioluminescent art" for Valentine's Day!  As described from time to time on this blog, I grew up cultures of Photobacterium leignothi and "wrote" onto Petri dishes containing appropriate nutrient medium.  I then incubated for a few hours, and voilá!

One the central concepts I discuss with students in all of my classes is how microbes communicate with one another using low molecular weight molecules. This chemical "language" can control gene expression, allowing some genes to only be activated at high population densities.   This process has come to be called "quorum sensing," and it is a very hot topic indeed in microbiology, controlling such diverse processes in many microbes as pathogenesis, pigment production, adhesion, and of course bioluminescence.

Since quorum sensing is a critical topic in biology, why not immortalize it on Valentine's Day, with bacteria using this very process to generate beautiful light in the darkness?  Here is one such image.

Another image image with the same theme.

In this photograph,  I am trying to get more reflection from the shelf on which the plates are propped.

And finally, I need to recognize the many roles my wife of 15 years, Dr. Jennifer J. Quinn, has played and continues to play in my life.  Jenny has exemplified loyalty, honor, professionalism, and love in ways that humble me daily.  I cannot imagine life without her.  Jenny brings light into my life so often, and I would like to commemorate that fact in bioluminescence here.

I hope that everyone reading this has a lovely, lovely Valentine's Day.  And considering how frequently microbes engage in horizontal gene transfer, I would like to wish your mutualistic and co-evolved diverse population of microbiota a romantic day as well!


  1. I am thankful to Elio too for listing this blog.

    Hope you don't mind if a rebel amateur scientist stops in now and then to extend the inquiries into the awesome world that has been undercover and undercovered IMO.

    1. "And considering how frequently microbes engage in horizontal gene transfer ..."

      Mark, I have been reading papers on this dynamic. It seems that there is some resistance to it. One of the papers I read was dealing with the "dark matter" (I don't like that term "yet") section where it has been discovered that a lot of the content is not preserved during the process of replication, therefore most of the "fingerprints" of horizontal transfer are not preserved. Thus, it requires a specialized method to detect that it took place.

    2. I don't know whose work you have been reading, but there is a LOT of DNA flitting about from cell to cell out there. I suspect you are thinking of this kind of thing:

      Or even:

      Tanja Woyke does great work!

      I also like Jon Eisen's talk.

      We are getting far away from bioluminescent Valentines, but thanks again for the comment.

  2. Replies
    1. Lots of people do microbial art these days...I'm just a novice. If you like that kind of thing, check out and some of the links on my page. Thanks again for your comment.


I am happy to hear your comments and suggestions. I hope to avoid spammage. We shall see how that works out!