Commenter JohnV asked me whether I had let any of my silkworms crawl on an LB plate (what microbiologists use to grow colonies of bacteria) to see what kind of bacteria is living on them in case I ever suffer from catastrophic experiment contamination. I hadn’t thought of what kind of bacteria could be living on my silkworms (we are thinking about what kind of bacteria live in their digestive systems that help them digest leaves) so I tried it out! I let one of my wormies crawl on a plate, and I touched one with my relatively clean fingers as a pseudo-control.

I let the plates incubate at 37 degrees celsius (body temperature, which a lot of bacteria like to grow at) overnight and then forgot about them and left them on my bench at room temperature for another night and then took a picture of them this morning:

Even though there are likely many more microbes present that don’t like to grow on LB plates, there are definitely more species of bacteria and fungus living on the silkworms than on my fingers (or in beards) but I don’t know if I’m any more worried about contamination or infection now than I was before.

Indeed, most of the experiments done for TV by Mythbusters or the evening news that show you how many bacteria are living on your everyday things are meant to scare you into buying horrible antibacterial wipes, but to me they just show how interconnected we are with the bacteria that surround us each day and how fragile that ecosystem is. We are lucky to live in a time and place where knowledge of microbiology, indoor plumbing, hand washing, and antibiotics have eradicated many of the bacterially mediated infectious diseases, but knowing that bacteria can cause disease makes many of us desire a sterility in our environment that is not only impossible but also dangerous. The fear of bacteria and overuse of antibiotics has led to an increase in actually deadly antibiotic-resistant infections as well as likely contributing to the increase in auto-immune disorders such as asthma and allergies. So let’s celebrate those bacteria that grow up on our LB plates when we swab our everyday surroundings!

Let’s do a little experiment: give me suggestions of things to swab and photograph in the comments (within reason) and we can start making a little family photo album of our bacterial buddies!