Even in bacteria, the lack of information and the speed of processing it restricts the performance and behavior of the organism

Organisms adapt their behavior and movement based on the information they obtain from their environment. However, this information may often be incomplete or incorrect. But it is imperative for living things to act even in such a state of uncertainty that the information provides. Does the abundance of information and the speed of its processing limit the performance of the organism?

Recently, a research study published by researchers from Yale University in the journal Nature Physics on November 25 provided an answer to this question.

The scientists’ findings showed that the information that Escherichia coli bacteria collect from their environment limits their performance in a process known as chemotaxis, which is the mechanism by which bacteria direct their movements in response to chemical signals around them. .

According to the report published by Phys.org, study researchers say that "since information theory was first formulated around 1950, scientists have realized that it can be a powerful tool governing how organisms deal with the hustle and bustle of the surrounding environment."

The majority of previous research has focused on studying how much information cells can obtain from their environment. Measurements collected so far indicate that biological systems transmit information effectively and are bound by basic controls imposed by the laws of physics.

However, "acquiring information is not the end of the day. It must be dealt with appropriately," says the study team. Therefore, researchers have sought to verify whether or not living organisms make the most of the information they gain by effectively performing their various behaviors and functions.

Information Acquisition Rate

The researchers chose a simple behavior - such as chemoattraction - to check how much information the bacteria would need to enforce this behaviour. During this behavior, the E. coli bacteria gather information about the chemical signals around them. It then uses this information to adjust its behavior and determine the direction it will take, either towards nutrients or away from toxic substances.

To determine the rate at which bacteria gather information during chemotaxis, the team had to understand how bacteria translate signals around them into corresponding activity.

Therefore, the team altered the concentrations of nutrients present in the bacteria's environment and then simultaneously measured the bacteria's activity. In some experiments, the team also suppressed such information (ie not providing these nutrients) and measured how much the bacteria's response was disrupted. Which enabled them - for the first time - to estimate the amount of information that bacteria can extract from their environment; And that as it travels in these gradients of chemical signals. To determine how quickly bacteria respond to these chemical gradients, the team followed the paths of the bacteria's swimming as they moved along these gradients.

Greater efficiency

The combination of measurements of the amount of information gained from the environment and the speed at which bacteria move along chemical gradients made it possible to know how efficiently bacteria use the information around them.

The team found that swimming in shallow environments caused the bacteria to gain little information from their environment. Its transmission rate was 0.01 bits/sec. For an approach, if the transmission of information on the Internet was at this rate, you would need thousands of years to get a copy of any traditional movie.

Thus, using little information at a speed close to what is theoretically possible indicates that this information must be used very efficiently to perform specific tasks.

The researchers conclude that "the rate of transmission of information in bacteria is many times lower than the rate that a cell uses to determine its orientation, estimated at 1 bit/sec. This is the first time that we have seen an application of information theory to place constraints on an organism's performance and behavior. The transmission of data and the ability to perform functions critical to keeping an organism alive.”