(First of three parts)
What an ugly blot on the human character. Despite our sheer intelligence, we have strong tendencies to spit out profanities, to gossip, backbite and badmouth people we envy and perceive as threats to our self-esteem and interests. Listen carefully and you will find out that such mindless talks have become daily plaques which never fail to ultimately breed discord and destruction most especially in the workplace even in the most advanced of human societies. But mind you, we share this world with countless mindless organisms which have no time for such mindless behavior even in the harshest of environments. These organisms are no other than bacteria! Bacteria are primitive and brainless yet when they communicate, unlike in a human senate or congress, there is no mayhem; it is muted, always precise, methodical and coordinated, ensuring the utmost benefit of the population.
The sound of silence
It is proposed that prehistoric man started communicating by sign language and eventually through spoken language. Who would have thought from the past century that we will be a generation where audible words from our vocal chords are not necessarily needed to socialize. Today, through our visual perceptions, we respond through electrical signals from our brains transmitted down to our fingertips resulting in strokes on the keyboards, keypads, touch screens and a few clicks on the mouse. This is the modern trend of efficiently sharing our thoughts and snippets of our lives whether across the street or around the world. How cool is that! But before you get cocky over our gadget-savvy and pixelated generation, think again. Billions of years ago, way before humans existed, microorganisms had already actually begun a sophisticated type of social communication, a phenomenon scientists call “Quorum Sensing.”
Reactions speak louder than words
Quorum sensing is the language of bacteria in the form of chemical signals which they release. Bacteria communicate with each other in order to react to the rapidly changing conditions in their environment like the availability of nutrients, evasion of toxic molecules, defense against other bacteria and so forth. The chemical signals must be in sufficient concentration, and that means there should be enough number of cells releasing them to trigger the expression of specific genes as a response to a specific environmental condition. Quorum sensing therefore can never be achieved by a single bacterium but only through a collective effort hence the term “quorum” which is defined as “a group with members competent of accomplishing an objective.” This is an amazing phenomenon wherein unicellular microorganisms are reacting to their environment in unison like a single multicellular organism. It accomplishes a task and reaps benefits as a group that cannot be attained as a single cell.
Strength and safety in numbers is therefore the essence of quorum sensing. It is the microbial version of the fascinating phenomenon of cooperative behavior seen in schools of fish moving in unison, a flock of migrating birds or swirling swarms of bats for protection against larger predators. Each member of the group tunes in to each other and reacts with unquestioning allegiance in the name of survival.
(To be continued)
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Dr. Ronie J. Calugay obtained his Ph.D. in Life Sciences and Biotechnology at the Department of Biotechnology, Tokyo University of Agriculture and Technology where he studied iron-shuttling molecules called siderophores produced by magnet-producing bacteria. He finished his MS in Microbiology at the University of the Philippines, Diliman. E-mail him at ronix5@yahoo.com.