Title |
A common evolutionary pathway for maintaining quorum sensing in Pseudomonas aeruginosa |
Author |
Bai-min Lai1, Hui-cong Yan1, Mei-zhen Wang1,2*, Na Li1,2, and Dong-sheng Shen1,2 |
Address |
1School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, P. R. China, 2Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou 310018, P. R. China |
Bibliography |
Journal of Microbiology, 56(2),83–89, 2018,
|
DOI |
10.1007/s12275-018-7286-1
|
Key Words |
Pseudomonas aeruginosa, long-term evolution,
quorum sensing, protease production, acyl-homoserine lactone,
cooperation and cheating |
Abstract |
In the bacterium Pseudomonas aeruginosa, the synthesis and
secretion of extracellular protease is a typical cooperative
behavior regulated by quorum sensing. However, this type
of cooperative behavior is easily exploited by other individuals
who do not synthesize public goods, which is known
as the “tragedy of the commons”. Here P. aeruginosa was inoculated
into casein media with different nitrogen salts added.
In casein broth, protease (a type of public good) is necessary
for bacterial growth. After 30 days of sequential transfer,
some groups propagated stably and avoided “tragedy of the
commons”. The evolved cooperators who continued to synthesize
protease were isolated from these stable groups. By
comparing the characteristics of quorum sensing in these
cooperators, an identical evolutionary pattern was found. A
variety of cooperative behaviors regulated by quorum sensing,
such as the synthesis and secretion of protease and signals,
were significantly reduced during the process of evolution.
Such reductions improved the efficiency of cooperation, helping
to prevent cheating. In addition, the production of pyocyanin,
which is regulated by the RhlIR system, increased
during the process of evolution, possibly due to its role in
stabilizing the cooperation. This study contributes towards
our understanding of the evolution of quorum sensing of P.
aeruginosa. |