Can the finding the right vibration be the key to new antibiotic production?
I met again with the microbiologist, Dr. Hobbs, whom I had mentioned in a previous post who is studying sound and bacteria. I learned that he and another scientist, Dr. Murphy, are researching the effects of vibrations on antibiotic production along with a team of students. Many antibiotics are produced by bacteria to act against different bacteria, as it gives them a competitive advantage. We can harvest this bioproduct for our own uses, and what Dr. Hobbs and his colleagues are researching could enhance our industrial-grade production of it.
The research mainly involves placing flasks of bacteria-rich fluid into a controlled environment and exposing them to vibration (usually at 400Hz), either by placing them on top of a small speaker or on top of a plate-like vibration generator. An identical flask always goes into a separate containment unit as a control.
The results show that the bacteria exposed to the 400Hz sound produce more product than the control, which can be seen in the resulting colours (darker indicating more product, lighter indicating less product). The chemical composition of the product is not yet certain, but the team of scientists are hoping to find out soon. Even if it is not an antibiotic, it may be another useful bioproduct.
The team is also planning on testing the effect of the traditional Chinese medicine, berberine, on this experiment.
I asked if they knew anything about ultrasound as it relates to bacterial growth. Dr. Murphy said that ultrasound is very high frequency and is more likely to disrupt bacteria than to nurture them.
Aside from antibiotics, this research raises other important questions. For instance, what does it mean for ecology? If you have a farm with large equipment creating intense vibrations, and we know that vibrations can change bacterial activities, it seems logical that those vibrations could affect the bacteria in the soil on the farm. This could have important implications for food production.
We have focused much research on bacterial communication through chemical means (like quorum sensing; check out this interview for more), but not so much on physical means. Dr. Murphy directed me to an article that discusses microbial communication through physical stimuli (including sound waves).
Dr. Hobbs told me about a phenomenon in which bioluminescent microorganisms glow in response to ocean waves. This interested me because sound is a wave, too, and because it is a great visual analog to this concept.