How Do Bacteria Smell? Very Well!

One of the fundamental ideas behind the evolutionary hypothesis is that organisms fall in a range from “simple” to “complex.” The organisms that are supposed to be simple, like bacteria, are assumed to be more reflective of the kinds of organisms that existed on earth a few billion years ago. As the evolutionist waves the magic wand of time, it is assumed that those “simple” organisms slowly evolved into “complex” organisms. What we see on earth today, then, is a range of complexity in nature. “Simple” organisms (like bacteria) are reminiscent of the first kinds of organisms that existed on earth, and “complex” organisms (like mammals) are the products of the long, slow process of macroevolution.

Of course, this goes counter to the creationist view. In the creationist view, organisms do not fall in a range from “simple” to “complex.” Instead, as my coauthor and I stress throughout our biology book, there is no such thing as a simple organism. Even organisms like bacteria are marvelously complex. Thus, if there is a range of complexity in creation, it is from “really complex” to “ridiculously complex.”

The more we learn about science, the more it confirms the creationist view of complexity. Organisms that evolutionists call “simple” are actually amazingly complex.

The most recent installment in this march to confirm the creationist view comes from Reindert Nijland and J. Grant Burgess. 1 They studied the bacterium Bacillus licheniformis. It is a common bacterium found in the soil and on bird feathers.2 It is a very useful bacterium, because it is easily cultured to produce an enzyme (protease) that breaks down proteins into water-soluble chemicals. That enzyme is widely used in biological washing powders.3

In the study, the authors learned that when ammonia is present, these bacteria form a slimy colony. It is assumed this happens because bacteria eat things like ammonium sulfate and convert them to ammonia. As a result, the presence of ammonia indicates that bacteria are eating, which signals the fact that food is present in the environment. Since these bacteria feed more effectively as a slimy colony than as a bunch of individuals, they tend to form the slimy colony when they detect ammonia. So…if you add ammonia to a dish that has some of these bacteria in it, the bacteria form a slimy colony in preparation for a feast.

Interestingly enough, however, the researchers found that you don’t have to add ammonia to the dish in order to get this response. Instead, if you put a dish containing only ammonia next to a dish that contains the bacteria, the bacteria will still form a slimy colony. In addition, if you put a dish of bacteria farther away from the ammonia-containing dish, the bacteria will still form a slimy colony, but not with the vigor of the bacteria close to the ammonia-containing dish.

What does this tell us? It tells us that the bacteria are sensing the airborne molecules of ammonia that are drifting out of the ammonia-containing dish and wafting to the bacteria-containing dishes. The farther the dish of bacteria is from the ammonia, the fewer airborne molecules reach the bacteria, and the weaker their response is. Nevertheless, the results are clear – bacteria are detecting airborne, food-related molecules.

What do we call it when organisms detect airborne molecules? We call it smelling. Thus, these bacteria are actually smelling the ammonia. Of course, bacteria are assumed to be so “simple” that no one expected them to have a sense of smell (which is typically called “olfaction”). Neverthelees, this paper shows that at least these bacteria do, indeed, have a sense of smell. That’s why the paper is entitled “Bacterial olfaction.”

One of these days, evolutionists will be forced to admit that there is no such thing as a simple organism. Until that day, creationists will just have to keep pointing out every new advance that illustrates this simple fact of nature.


1. Reindert Nijland and J. Grant Burgess, “Bacterial olfaction,” Biotechnology Journal 2010, available online
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2. Frank B. Gill, Ornithology, W. H. Freeman (third edition), 2006, p. 95
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3. Andrew Allott, Biology for the IB Diploma: standard and higher level, Oxford University Press, 2001, p. 15
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8 thoughts on “How Do Bacteria Smell? Very Well!”

  1. I just found your blog and I am enjoying it very much. I am a scientist by education, but a homeschool Mom by choice. As such, it can be difficult to keep up on all the scientific research. I appreciate blogs such as yours, where I can learn about the latest discoveries and imagine again, for a moment, that I’m back in the lab running experiments myself.

    1. Shevrae, I am so glad that you find this blog enjoyable and that it satisfies your desire to keep up with the latest advances in science!

  2. Wow, this is SO cool! Since my biology ed came from your book, I’ve always thought with the mindset that there are no simple organisms and only complex.. but this is wayyyyy cool. Bacteria smell?! that’s amazing.

    1. Excellent link, Eric. WordPress closes the comments after a time, but I think I will add this as a new article, because it is very good. While the author still seems to want to believe autism is not really increasing, the Bearman study argues against that much more forcefully than the author can argue for it. Note that the Bearman study confirms the comments of my original post, that parental age is one of the factors involved in the real increase of autism rates.

  3. My first thought on reading this article – why all the fuss since simple and complex are relative terms.

    But later I realized that for evolution to be true, there should be “absolutely” simple organisms that have been easily formed during the initial stage. I believe you are highlighting the lack of “absolutely” simple organisms to attack evolution theory.

    I have one question for you: This smelling ability of bacteria could also have been evolved (micro evolution) during billions of years, right? How can you be sure that this bacteria has always been this complex?

    I’m no scientist, but just pointing out that logically, this is not necessarily out of line with evolution theory.

    1. NoOne, you are correct that this smelling ability could have evolved over billions of years. I doubt that it could have been the result of microevolution, since I would think it requires a host of specialized proteins, etc. Until the pathway is characterized, however, we won’t know for sure. So I will certainly grant the possibility that it could have evolved.

      Scientists must go with the data at hand. Right now, bacteria are the simplest form of life that we know. Until we find something that is both alive and simpler, we have to use them as the model for the simplest that life can get. As this and many other studies show, bacteria are already marvelously complex. This, once again, is confirmation of the creationist view, that there is no such think as a simple organism.

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