The algicidal activity of Aeromonas sp. strain GLY-2107 against bloom-forming Microcystis aeruginosa is regulated by N-acyl homoserine lactone-mediated quorum sensing

• Published in: Environmental microbiology 2016-11, Vol.18 (11), p.3867-3883
• Main Authors: Guo, Xingliang, Liu, Xianglong, Wu, Lishuang, Pan, Jianliang, Yang, Hong
• Format: Article
• Language: English
• Subjects: 4-Butyrolactone - analogs & derivatives; 4-Butyrolactone - metabolism; Aeromonas - genetics; Aeromonas - physiology; Antibiosis; Chromatography, Thin Layer; Eutrophication; Lakes - microbiology; Microcystis - growth & development; Quorum Sensing
• ISSN: 1462-2912; 1462-2920
• DOI: 10.1111/1462-2920.13346

Summary Cyanobacterial blooms have disrupted the efficient utilization of freshwater worldwide. A new freshwater bacterial strain with strong algicidal activity, GLY‐2107, was isolated from Lake Taihu and identified as Aeromonas sp. It produced two algicidal compounds: 2107‐A (3‐benzyl‐piperazine‐2,5‐dione) and 2107‐B (3‐methylindole). Both compounds exhibited potent algicidal activities against Microcystis aeruginosa, the dominant bloom‐forming cyanobacterium in Lake Taihu. The EC50 values (concentration for 50% maximal effect) of 3‐benzyl‐piperazine‐2,5‐dione and 3‐methylindole were 4.72 and 1.10 μg ml−1 respectively. Based on a thin‐layer chromatography biosensor assay and ultra‐performance liquid chromatography‐coupled high resolution‐tandem mass spectrometry (UPLC‐HRMS/MS), the N‐acyl homoserine lactone (AHL) profile of strain GLY‐2107 was identified as two short side‐chain AHLs: N‐butyryl‐homoserine lactone (C4‐HSL) and N‐hexanoyl‐homoserine lactone (C6‐HSL). The production of the two algicidal compounds was controlled by AHL‐mediated quorum sensing (QS), and C4‐HSL was the key QS signal for the algicidal activity of the strain GLY‐2107. Moreover, 3‐methylindole was found to be positively regulated by C4‐HSL‐mediated QS, whereas 3‐benzyl‐piperazine‐2,5‐dione might be negatively controlled by C4‐HSL‐mediated QS. This study suggests that a QS‐regulated algicidal system may have potential use for the development of a novel control strategy for harmful cyanobacterial blooms.