WEBVTT 00:00:07.049 --> 00:00:10.470 Why do we love microbes? And how do microbiologists 00:00:10.470 --> 00:00:13.630 choose their favorite microbe? This is what I'll 00:00:13.630 --> 00:00:17.089 explore in today's episode. Hello, I'm Lori 00:00:17.089 --> 00:00:20.589 Daane, and welcome to My Favorite Microbe, a podcast 00:00:20.589 --> 00:00:23.550 where we ask guests one deceptively simple question. 00:00:23.949 --> 00:00:27.070 What's your favorite microbe and why? As you 00:00:27.070 --> 00:00:29.410 listen today, I invite you to think about your 00:00:29.410 --> 00:00:32.560 own favorite microbe. Or if you're not a microbiologist, 00:00:32.780 --> 00:00:35.500 maybe simply the organism that first made you 00:00:35.500 --> 00:00:39.240 realize the microbial world is amazing. When 00:00:39.240 --> 00:00:41.759 I released the trailer, friends immediately asked, 00:00:42.000 --> 00:00:44.799 what's your favorite microbe? That wasn't supposed 00:00:44.799 --> 00:00:48.219 to happen. I planned to ask guests, not answer 00:00:48.219 --> 00:00:51.799 it myself. As a microbial ecologist, I usually 00:00:51.799 --> 00:00:53.939 think about communities rather than individual 00:00:53.939 --> 00:00:57.579 organisms. Asking me to choose is a little like 00:00:57.579 --> 00:01:00.460 asking me to choose my favorite color or my favorite 00:01:00.460 --> 00:01:04.920 band. The answer changes over time. The more 00:01:04.920 --> 00:01:07.200 I thought about it, the more I realized this 00:01:07.200 --> 00:01:09.780 episode isn't really about naming my favorite 00:01:09.780 --> 00:01:12.859 microbe. It's about why microbiologists become 00:01:12.859 --> 00:01:16.159 attached to certain organisms. So today I'll 00:01:16.159 --> 00:01:18.780 walk you through how I made my choice and why 00:01:18.780 --> 00:01:21.079 it became far more emotional than I expected. 00:01:22.319 --> 00:01:25.140 If I think about finding my favorite, The first 00:01:25.140 --> 00:01:27.739 thing I ask myself is, what makes it memorable? 00:01:29.000 --> 00:01:31.500 Some microbiologists love medically important 00:01:31.500 --> 00:01:34.579 organisms. These are the villains or bad guys 00:01:34.579 --> 00:01:37.700 of microbiology. Think Yersinia pestis in the 00:01:37.700 --> 00:01:41.019 Black Death or Clostridium tetani causing tetanus. 00:01:41.500 --> 00:01:44.379 Here's one of my favorite historical microbiology 00:01:44.379 --> 00:01:47.769 stories. John Roebling, the original designer 00:01:47.769 --> 00:01:50.950 of the Brooklyn Bridge, actually died of tetanus 00:01:50.950 --> 00:01:53.909 before construction began after crushing his 00:01:53.909 --> 00:01:57.170 foot in a ferry accident. His son, Washington, 00:01:57.450 --> 00:02:00.349 became chief engineer and was credited with completing 00:02:00.349 --> 00:02:03.349 the bridge, when in reality it was most likely 00:02:03.349 --> 00:02:07.010 completed by Washington's wife, Emily. I first 00:02:07.010 --> 00:02:09.490 learned that story from David McCullough's wonderful 00:02:09.490 --> 00:02:13.689 book, The Great Bridge. And by the way, it's 00:02:13.689 --> 00:02:16.569 probably worth asking yourself, when was your 00:02:16.569 --> 00:02:21.169 last tetanus shot? Historical importance could 00:02:21.169 --> 00:02:24.189 certainly make a microbe memorable, but that's 00:02:24.189 --> 00:02:27.750 not how I chose mine. I've always been fascinated 00:02:27.750 --> 00:02:30.210 by microbes that live where nothing else should 00:02:30.210 --> 00:02:34.129 survive, the extremophiles. I think I've watched 00:02:34.129 --> 00:02:37.189 every documentary on deep -sea hydrothermal vents. 00:02:37.689 --> 00:02:41.099 From an evolutionary standpoint, Extremophiles 00:02:41.099 --> 00:02:43.560 are especially fascinating because they help 00:02:43.560 --> 00:02:47.379 us understand the limits of life. Extremophiles 00:02:47.379 --> 00:02:49.539 are also of interest because of their potential 00:02:49.539 --> 00:02:52.759 for bioremediation of environments made hazardous 00:02:52.759 --> 00:02:54.979 to humans due to pollution or contamination. 00:02:55.800 --> 00:02:59.139 Leave it to a microbe to adapt to exploit an 00:02:59.139 --> 00:03:03.840 environment. True story. When I was in grad school 00:03:03.840 --> 00:03:06.819 taking, I think it was a behavioral ecology class, 00:03:07.360 --> 00:03:09.699 The professor, who was an ornithologist, said, 00:03:09.879 --> 00:03:13.180 can you imagine how terrible it would be if there 00:03:13.180 --> 00:03:15.460 was a microorganism that could eat gasoline? 00:03:16.360 --> 00:03:18.879 I looked around thinking, is this guy joking? 00:03:19.500 --> 00:03:22.219 I think I was the only microbial ecologist in 00:03:22.219 --> 00:03:24.960 the class, and I was too insecure at the time 00:03:24.960 --> 00:03:27.759 to speak up about how microbial populations evolve 00:03:27.759 --> 00:03:30.460 as you move away from the most heavily contaminated 00:03:30.460 --> 00:03:33.939 part of a pollution plume. In fact, scientists 00:03:33.939 --> 00:03:36.740 go to these environments to collect samples specifically 00:03:36.740 --> 00:03:39.740 looking for extreme microbial metabolic diversity. 00:03:40.699 --> 00:03:43.439 So perhaps my favorite would be an extremophile. 00:03:43.759 --> 00:03:48.199 That would make sense, but it isn't. To understand 00:03:48.199 --> 00:03:50.900 my actual choice, we need to go back to my first 00:03:50.900 --> 00:03:54.639 postdoc at Rutgers University. I joined Dr. Max 00:03:54.639 --> 00:03:58.250 Häggblom's laboratory in the late 1990s. At the 00:03:58.250 --> 00:04:01.289 time, Max was a young, untenured assistant professor 00:04:01.289 --> 00:04:04.110 with a couple of graduate students and three 00:04:04.110 --> 00:04:07.169 postdocs. We called ourselves the Bloomer Lab, 00:04:07.389 --> 00:04:11.090 and we were the original bloomers. One of my 00:04:11.090 --> 00:04:13.229 first tasks was to collect sediment and salt 00:04:13.229 --> 00:04:15.789 marsh plants from a somewhat contaminated area 00:04:15.789 --> 00:04:18.850 in New Jersey. I remember that it was low tide, 00:04:19.069 --> 00:04:21.290 and I had to use two pieces of plywood to get 00:04:21.290 --> 00:04:24.379 out a bit to grab plants and sludge. It looked 00:04:24.379 --> 00:04:26.699 like black mayonnaise, and without the plywood, 00:04:26.980 --> 00:04:29.680 I might have sunk into the sludge and been unable 00:04:29.680 --> 00:04:33.040 to get back out. I remember the smell to this 00:04:33.040 --> 00:04:35.720 day, and looking at the surface of the sediment, 00:04:35.819 --> 00:04:38.899 you could see what looked like gas or fuel swirled 00:04:38.899 --> 00:04:41.779 within the water. Let's just say, lighting a 00:04:41.779 --> 00:04:45.100 match would not have been a good idea. I wasn't 00:04:45.100 --> 00:04:47.899 there alone. Monica, a postdoc in another lab, 00:04:48.040 --> 00:04:50.959 came with me. She was standing on a bridge that 00:04:50.959 --> 00:04:53.519 spanned the area where I was sampling. and at 00:04:53.519 --> 00:04:56.040 one point, I looked up and saw her talking to 00:04:56.040 --> 00:04:58.920 two police officers. I couldn't hear what they 00:04:58.920 --> 00:05:02.199 were talking about, but at one point, one of 00:05:02.199 --> 00:05:04.519 the police officers yelled out to me to make 00:05:04.519 --> 00:05:07.100 sure to let them know if I find a body or a gun. 00:05:07.759 --> 00:05:11.540 It was New Jersey. At the time, it just felt 00:05:11.540 --> 00:05:14.240 like another day of fieldwork. Looking back, 00:05:14.399 --> 00:05:16.639 it became one of those stories scientists tell 00:05:16.639 --> 00:05:20.399 for the rest of their careers. Back in the lab, 00:05:20.560 --> 00:05:23.079 I used those sediment and root -associated samples 00:05:23.079 --> 00:05:26.319 to isolate spore -forming bacteria capable of 00:05:26.319 --> 00:05:29.500 degrading polyaromatic hydrocarbons, the pollutants 00:05:29.500 --> 00:05:32.920 we were studying. One group turned out to represent 00:05:32.920 --> 00:05:36.160 a previously undescribed species of Penibacillus. 00:05:36.519 --> 00:05:39.860 For a microbiologist, helping discover and describe 00:05:39.860 --> 00:05:42.779 a new species is a little like an astronomer 00:05:42.779 --> 00:05:47.139 helping identify a new star. Now I should mention 00:05:47.139 --> 00:05:49.540 that Max's lab benefited from the involvement 00:05:49.540 --> 00:05:53.180 of an important adjunct professor, Dr. Norberto 00:05:53.180 --> 00:05:57.839 Palleroni, who passed away in 2018 at age 96. 00:05:58.519 --> 00:06:02.240 When I was at Rutgers, he was about 75 and still 00:06:02.240 --> 00:06:05.680 came into the lab to mentor students. So I had 00:06:05.680 --> 00:06:08.259 the great fun and honor of helping to characterize 00:06:08.259 --> 00:06:11.459 and describe a new species which Norberto helped 00:06:11.459 --> 00:06:15.569 us name, Penibacillus naphthalenovorans. which 00:06:15.569 --> 00:06:19.649 means naphthalene devouring. I'm extremely proud 00:06:19.649 --> 00:06:21.930 to have published this work with Norberto Palleroni. 00:06:22.230 --> 00:06:26.230 Now with that said, Penibacillus naphthalenovorans 00:06:26.230 --> 00:06:30.850 is not my favorite microbe. For those who may 00:06:30.850 --> 00:06:33.490 not know, Dr. Palleroni was an internationally 00:06:33.490 --> 00:06:36.870 recognized authority in bacterial taxonomy, particularly 00:06:36.870 --> 00:06:39.870 the genus Pseudomonas. In fact, people called 00:06:39.870 --> 00:06:43.100 him the father of pseudomonads. I recall being 00:06:43.100 --> 00:06:45.639 at a microbiology conference where Norberto attended, 00:06:45.899 --> 00:06:48.439 and people were lining up to meet him and exchange 00:06:48.439 --> 00:06:52.259 stories about taxonomy and pseudomonas. In preparing 00:06:52.259 --> 00:06:55.180 for this episode, I found two printed publications 00:06:55.180 --> 00:06:59.560 that Norberto gave me. On a paper about prokaryotic 00:06:59.560 --> 00:07:02.100 diversity and the importance of culturing, he 00:07:02.100 --> 00:07:06.420 wrote, To Dear Lori Daane, Affectionately, Norberto. 00:07:07.459 --> 00:07:10.689 The second was a chapter titled, Introduction 00:07:10.689 --> 00:07:13.829 to the Aerobic Pseudomonads. He gave it to me 00:07:13.829 --> 00:07:16.009 after we characterized a new species together. 00:07:16.529 --> 00:07:19.889 This time he wrote, To my friend and colleague, 00:07:20.009 --> 00:07:24.470 Lori. Affectionately, Norberto. It's been almost 00:07:24.470 --> 00:07:27.949 30 years and I still have both papers. I'll put 00:07:27.949 --> 00:07:30.089 a link to the published memoriam in the show 00:07:30.089 --> 00:07:32.329 notes so you can learn more about this amazing 00:07:32.329 --> 00:07:37.089 microbiologist. Now let's get back to choosing 00:07:37.089 --> 00:07:41.759 my favorite. So it isn't an extremophile, it 00:07:41.759 --> 00:07:45.319 isn't a pathogen with a dramatic history, and 00:07:45.319 --> 00:07:48.459 surprisingly, it isn't even the organism I helped 00:07:48.459 --> 00:07:54.420 describe as a new species. I chose Stenotrophomonas 00:07:54.420 --> 00:08:00.180 maltophilia. Say it with me. Stenotrophomonas 00:08:00.180 --> 00:08:04.240 maltophilia. It sounds musical, and it just rolls 00:08:04.240 --> 00:08:08.399 off the tongue. Interestingly enough, in 1993, 00:08:08.939 --> 00:08:13.160 Norberto and J .F. Bradbury introduced Stenotrophomonas 00:08:13.160 --> 00:08:16.439 as a new bacterial genus, with Stenotrophomonas 00:08:16.439 --> 00:08:20.560 maltophilia. as the single species. Before listing 00:08:20.560 --> 00:08:23.180 three fast facts, let's break down the name. 00:08:24.139 --> 00:08:28.560 Steno means narrow, trophos means one who feeds, 00:08:28.800 --> 00:08:32.200 and monos means a single unit. When you put it 00:08:32.200 --> 00:08:35.559 together, the genus roughly means a unit feeding 00:08:35.559 --> 00:08:39.679 on few substrates. Maltophilia means malt -loving. 00:08:39.740 --> 00:08:42.820 So there you have it, the narrow feeder that 00:08:42.820 --> 00:08:48.159 loves malt. Now some fast facts. It has had an 00:08:48.159 --> 00:08:51.679 identity crisis. It was first found in a pleural 00:08:51.679 --> 00:08:55.679 effusion in 1943 and given the name Bacterium 00:08:55.679 --> 00:08:59.700 bookeri. Over the decades, it moved from bacterium 00:08:59.700 --> 00:09:03.980 to Pseudomonas, then Xanthomonas, and finally 00:09:03.980 --> 00:09:09.059 Stenotrophomonas in 1993. It's ubiquitous, widely 00:09:09.059 --> 00:09:12.240 distributed in water, soil, and plant -associated 00:09:12.240 --> 00:09:15.480 environments, and it's particularly good at attaching 00:09:15.480 --> 00:09:19.399 to surfaces and forming biofilms. It has emerged 00:09:19.399 --> 00:09:22.580 as an opportunistic human pathogen and can be 00:09:22.580 --> 00:09:25.440 multidrug -resistant, making it difficult to 00:09:25.440 --> 00:09:30.240 treat. Bonus fact, a close relative Stenotrophomonas 00:09:30.240 --> 00:09:34.019 rhizophila has been proposed as a safer alternative 00:09:34.019 --> 00:09:38.120 for biotechnological applications. Looking back 00:09:38.120 --> 00:09:40.860 at my process, I thought I chose this organism 00:09:40.860 --> 00:09:44.419 because I liked the sound of its name. But when 00:09:44.419 --> 00:09:47.820 you hear Stenotrophomonas maltophilia., you may 00:09:47.820 --> 00:09:52.039 simply hear the name of a bacterium. I hear Norberto 00:09:52.039 --> 00:09:56.399 Palleroni. I remember Max Häggblom's lab. the 00:09:56.399 --> 00:09:59.100 original bloomers, and the excitement of being 00:09:59.100 --> 00:10:02.620 a young scientist doing what I loved. That is 00:10:02.620 --> 00:10:04.899 why I think microbiologists often choose their 00:10:04.899 --> 00:10:07.980 favorite through emotional attachment. It isn't 00:10:07.980 --> 00:10:10.700 necessarily about medical importance, metabolic 00:10:10.700 --> 00:10:13.679 diversity, or even how it looks on an agar plate. 00:10:14.259 --> 00:10:17.320 It is about connecting to a place and time and 00:10:17.320 --> 00:10:20.740 the people in our lives. I thought choosing a 00:10:20.740 --> 00:10:23.240 favorite microbe would be impossible, but in 00:10:23.240 --> 00:10:25.929 the end, I realized my favorite wasn't really 00:10:25.929 --> 00:10:29.289 about the organism. Maybe that's true for all 00:10:29.289 --> 00:10:32.450 microbiologists. Maybe every favorite microbe 00:10:32.450 --> 00:10:35.690 is really a story about a mentor or a discovery 00:10:35.690 --> 00:10:39.549 or a turning point in someone's life. That's 00:10:39.549 --> 00:10:42.029 exactly what I hope to find as I begin asking 00:10:42.029 --> 00:10:45.470 guests one simple question. What's your favorite 00:10:45.470 --> 00:10:49.470 microbe? I'm Lori Daane, and thank you for listening. 00:10:49.960 --> 00:10:52.620 You can send me your favorite microbe or suggest 00:10:52.620 --> 00:10:55.820 a future guest at myfavoritemicrobe at gmail 00:10:55.820 --> 00:11:00.100 .com. Please subscribe and like and join me next 00:11:00.100 --> 00:11:02.799 time for another favorite microbe.