A common evolutionary pathway for maintaining quorum sensing in Pseudomonas aeruginosa

• Published in: The journal of microbiology Vol. 56; no. 2; pp. 83 - 89
• Main Authors: Lai, Bai-min, Yan, Hui-cong, Wang, Mei-zhen, Li, Na, Shen, Dong-sheng
• Format: Journal Article
• Language: English
• Published: Seoul The Microbiological Society of Korea 01.02.2018; Springer Nature B.V; 한국미생물학회
• Subjects: Acyl-Butyrolactones - metabolism; Bacteria; Bacterial Proteins - metabolism; Biological Evolution; Biomedical and Life Sciences; Casein; Caseins - metabolism; Cooperation; Detection; Evolution; Exploitation; Extracellular; Life Sciences; Microbial Systematics and Evolutionary Microbiology; Microbiology; Nitrogen - metabolism; Peptide Hydrolases - biosynthesis; Peptide Hydrolases - secretion; Protease; Proteinase; Pseudomonas aeruginosa; Pseudomonas aeruginosa - growth & development; Pseudomonas aeruginosa - metabolism; Pyocyanin; Pyocyanine - metabolism; Quorum Sensing - physiology; Salts; Secretion; Signal Transduction - physiology; Stabilizing; Synthesis; 생물학; cooperation and cheating; quorum sensing; acyl-homoserine lactone; long-term evolution; protease production; Pseudomonas aeruginosa
• ISSN: 1225-8873; 1976-3794
• DOI: 10.1007/s12275-018-7286-1

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 .