Future Applications And Directions

Future Applications

There are several ways manipulating the rotation of flagella in E. coli can be applied, but there are two that specifically stand out. We begin with the improvement in communication between scientist and bacteria. As of now, much is known on how bacteria can communicate with each other, but little research has been completed on how bacteria can communicate with the researcher. By being able to convert the rotational frequency of flagella to sound, scientists can potentially understand the status of their bacteria. When there is enough food and the conditions in their environment are just right, bacteria should be able to produce a specific audible frequency that indicates that it is at an optimal state. However, there are many factors, such as starvation, outside, and presence of fungus, that we predict would skew the rotational frequency away from its optimal peak. With this information, a scientist can remedy the affecting condition before it hinders the functionality of the bacteria for research purposes.

In addition to allowing E. coli to communicate with researchers, we can also generate an equally as interesting phenomenon: singing bacteria. The bacteria flagella are rotating at certain frequencies, and these frequencies can be scales to correspond to the frequencies of musical notes. For example, a rotation of 220 Hertz corresponds to the A below middle C on a piano. By varying the temperature, pH, nitrate, salt, or glucose concentration, etc., of the E. coli’s environment, in tandem with controlling the expression of cheY and cheZ, we can adjust the frequencies of rotation, and therefore the musical notes they produce.

Using our program, we could actually generate an E. coli keyboard. Each plate of bacteria would produce a different frequency and thus a different note on the keyboard. Reported flagella rotation frequencies vary from 150 Hz to 450 Hz and we can produce an infinite number of permutations by varying combinations of promoters, number of flagella per bacterium, and environmental conditions.

At the current moment, the E. coli are perpetually rotating at a certain frequency, as though the piano player is mashing down all the piano keys at once. However, scientists have isolated the genes qseB and qseC ,which link quorum sensing to flagella rotation. Quorum sensing is bacteria to bacteria communication facilitated through chemical autoinducers that are released based on population density. QseB and QseC are like the hands of the piano player, which determine which keys to press and for how long to actually create a coherent melody. By adding a T7-dependent promoter to the quorum sensing-flagella pathway, rotation is induced when we add T7 to the bacteria’s environment. In this manner, we can potentially control how long each note plays for and in what order the notes play.

Thus, with our E. coli keyboard, we could play most songs, such as Top 40 pop melodies – or theoretically even Beethoven’s 9th. Our E. coli rotates in the lower octave ranges, so they’re more along the lines of basses or tenors. Their range is also more limited than a conventional piano.

Furthermore, we also believe that our project is a good example of a method for public relations for both synthetic biology and scientific research and also representative of a multidisciplinary approach to link the arts and the sciences.

Future Directions

Although we loved turning E. coli into a music-generating machine, we don’t want to leave you with the impression that our project only has aesthetic value. There are many practical and immediate implications! First and foremost, how many bacteriologists would love a direct readout to tell them how their bacteria are feeling? Are they hot or cold, hungry or full, contaminated or growing in pristine conditions? All these tests are possible. Moreover, a better understanding of flagella structure and function will further the efforts of labs and researchers currently tackling fundamental biological questions revolving around, bacteriology, immunity, and fertility. As such, we believe our project will have far reaching implications in real world.