July 10, 2025
Wastewater
Quorum Sensing: The Talk Of The Town In Bacteria World
In the late 19th and early 20th centuries, wastewater treatment plants became prominent all over the world.
Over time, various technologies and treatment solutions have been developed to effectively treat wastewater.
The primary goal has always been to protect the environment and prevent health hazards to humans.
Various research studies have been undertaken over the past few decades.
One of the fascinating discoveries made was about Quorum Sensing, which has become the talk of the town in the bacterial world.
As you may already know, there are three stages in wastewater treatment: Physical, Biological, and Chemical treatment.
Out of these, biological sewage treatment is the most crucial process for removing unwanted toxins, pollutants, and other harmful substances from wastewater.
You may also be familiar with the role microbes play in wastewater treatment, breaking down organic matter completely.
There are two types of wastewater treatment methods: aerobic and anaerobic, where microbes act on the waste in the presence and absence of oxygen, respectively.
But did you know that these tiny and powerful microbes can communicate with each other?
Yes, they do.
What is Quorum Sensing?
Technically, Quorum Sensing is a communication mode for the microbial community that helps regulate ecological and physiological behaviour to achieve a particular physiological function, which a single bacterium will be unable to perform.
To put it simply, Quorum Sensing is the chemical language that helps the bacterial community to converse with each other and facilitates group behaviour.
This means that microbes use chemical signals or gene expression to monitor and coordinate group action.
In the sewage treatment process, microbes present in large numbers vote, and if all the votes are unanimous, specific action occurs.
Experts believe that this phenomenon plays a major role in the formation of biofilm and granular sludge.
Moreover, it may be essential to enhance the activity of bacteria in the biological wastewater treatment process.
Discovery of Quorum Sensing
In the 1970s, Quorum Sensing was first proposed by Nelson and Miller, who discovered bacterial cell interactions while studying two bacteria, Streptococcus pneumoniae and Vibrio fischeri.
Later, Quorum Sensing was established in two marine bacteria, Vibrio fischeri and Vibrio harveyi.
It was discovered that a chemical signaling molecule known as an autoinducer was released to communicate between the bacteria.
Using different types of signaling molecules, bacteria regulate gene expression for various activities, including pathogenesis, bioluminescence, mobility, and biofilm formation, in wastewater treatment.
Quorum Sensing – QS systems can be divided into the following categories:
- Gram-negative systems mediated by Acyl-homoserine lactones – AHLs
- Gram-negative and positive bacteria mediated by diester furborate – AI-2
- Gram-positive bacteria are mediated by Autoinducing Peptide – AIP
- Other signal molecules include diffusible signal factor (DSF), autoinducer 3 (AI-3), and diguanylate monophosphate cyclic-di-GMP, a second messenger.
In wastewater treatment, AHLs are the main type of signaling molecules found.
Importance of Quorum Sensing in Wastewater Treatment
In wastewater, biofilm plays a crucial role in the growth and survival of microbes.
They help bacteria to tolerate the environmental pressure in treatment plants and prepare an environment where bacteria can thrive.
Several studies have demonstrated a significant correlation between biofilms and quorum-sensing signal molecules, specifically AHLs.
In the initial stages of research, mutated bacterial strains were produced by removing the QS signal.
It showed that bacteria ruptured the biofilm.
Later, an AHL signal molecule was added, stabilizing the biofilm.
Further studies have shown that the optimal amount of AHLs can enhance communication among the bacterial population and improve the pollutant removal process.
Some of the QS bacteria identified in sewage treatment plants include Anaerobic Ammonium-Oxidizing bacteria, ammonia-oxidizing bacteria, and Nitrite-Oxidizing bacteria (NOB).
Today, due to population explosion, rapid urbanization, and massive industrialization, sewage treatment plants are under undue stress.
The extensive amount of waste generated from households, industries, and agricultural activities has significantly burdened the treatment plants.
Thus, there is an urgent need for innovative solutions based on the latest scientific studies and discoveries, like Quorum Sensing.
Organica Biotech is one of the leading companies that has developed advanced biological treatment solutions for sewage treatment, the result of years of dedicated research in the field.
Cleanmaxx is one such solution that is effective for wastewater treatment.
It consists of a highly powerful blend of heterogeneous microbes capable of degrading pollutants into simple compounds.
Micro-encapsulated in powder form, it promotes high biomass generation and accelerates COD/BOD reduction.
One of the highlights of Cleanmaxx is that it can sense, adapt, and treat wastewater effectively; therefore, it is used in a wide range of industries.
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