The research team of Dr. Choong-Min Ryu and Dr. Kwang-Sun Kim at the Superbacteria Research Center of KRIBB found that the odor  (volatile organic compound) emitted from a specific bacterium affects the other bacteria’s behavior., They reported in 「Nature Communications」, a sister magazine of Nature, their findings including the mechanism where the bacterial odors changes the other bacteria's resistance to antibiotics and influences its motility.

It has been well known phenomenon that direct exchanging chemical signals between bacteria causes physiological response of bacteria such as quorum sensing that is population-dependent bacterial behavior change through specific signals. However, the research team provides a new insight into the communication between bacteria even when spatially separated through airborne signals. 

The research team employed recent cutting-edge genomics technologies to understand the phenomenon. Using I-plate that placed a barrier in the middle of Petri-dish (a culture container) to be divided two compartments, they grew Bacillus subtilis on one side and E. coli on the other side, and analyzed how the odor of B. subtilis affects E. coli even though they grow under physically separated condition from each other.

In this experiment, they observed that the expression of 160 E. coli genes changed rapidly within six hours after B. subtilis started to produce off its scents. In particular, E. coli genes related to motility and stress resistance are major responsing to the odor.

The research team later conducted another experiment where they found E. coli mutants that lost its motility after being affected by the smell of B. subtilis on I-plate.

Furthermore, they studied how E. coli responds to antibiotics after it is exposed to the volatiles of B. subtilis and consequently loses motility. According to the result, there were 13 antibiotics to be a change in the E. coli's susceptibility Among 13, three types of Cephalosporin antibiotics showed higher efficacy.

This implies that volatile substance of bacteria could serve as a supplement to antibiotics capable of effectively treating the bacteria resistant to Cephalosporin antibiotics, which is one of the most commonly, used antibiotics recently.