Qilu University of Technology (Shandong Academy of Sciences), Shandong Analysis and Test Center, Jinan, 250014, China; School of Pharmaceutical Sciences, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250014, China.
Qilu University of Technology (Shandong Academy of Sciences), Shandong Analysis and Test Center, Jinan, 250014, China; School of Pharmaceutical Sciences, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250014, China.
Chemosphere. 2020 Nov;259:127430. doi: 10.1016/j.chemosphere.2020.127430. Epub 2020 Jun 20.
The frequent outbreaks of cyanobacterial blooms which caused serious societal and economic loss have become a worldwide problem. Interactions between toxic cyanobacteria and heterotrophic bacteria competitors play a pivotal role in the formation of toxic cyanobacterial bloom, but the underlying mechanisms of interactions between them await further research. The antagonist activity of Pseudomonas grimontii (P.grimontii) was confirmed by reduction in chlorophyll a concentration of Microcystis aeruginosa (M. aeruginosa) in an infected culture for a 7d period. The initial concentration of P.grimontii affected the M. aeruginosa activity significantly. When the 10% (V/V) concentration of P.grimontii A01 and P.grimontii A14 cultures were infected, the reduction of M. aeruginosa reached to 91.81% and 78.25% after 7 days, respectively. While a 0.1% (v/v) concentration of P.grimontii A01 and P.grimontii A14 cultures were infected, the M. aeruginosa increased 31.13% and 16.67% occurred, respectively. The content of reactive oxygen species (ROS) and malondialdehyde (MDA) increased with increasing of P.grimontii fermentation liquid, indicating the M. aeruginosa underwent oxidative stress. Using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) imaging mass spectrometry (IMS) profiling of co-cultures of M. aeruginosa and its antagonist P.grimontii, we revealed novel interspecies allelopathic interactions and compete molecule. We showed the spatial secondary metabolites may mediate the interactions in which P.grimontii inhibits growth of M. aeruginosa. Additionally, we revealed how M. aeruginosa feedback to the P.grimontii, which stimulates secondary metabolites such as [D-Asp3]-microcystin-LR released by M. aeruginosa. IMS method highlights the significance of allelopathic interactions between a widely distributed toxic cyanobacteria and its bacteria competitors.
蓝藻频繁爆发水华，造成严重的社会和经济损失，已成为全球性问题。有毒蓝藻与异养细菌竞争者之间的相互作用在有毒蓝藻水华的形成中起着关键作用，但它们之间相互作用的潜在机制仍有待进一步研究。铜绿假单胞菌（P. grimontii）通过在感染培养物中在 7 天的时间内降低铜绿微囊藻（M. aeruginosa）的叶绿素 a 浓度来证实其拮抗活性。铜绿假单胞菌的初始浓度对 M. aeruginosa 的活性有显著影响。当感染 10%（V/V）浓度的铜绿假单胞菌 A01 和 P. grimontii A14 培养物时，M. aeruginosa 的减少分别达到 7 天后的 91.81%和 78.25%。而当感染 0.1%（v/v）浓度的铜绿假单胞菌 A01 和 P. grimontii A14 培养物时，M. aeruginosa 分别增加了 31.13%和 16.67%。活性氧（ROS）和丙二醛（MDA）的含量随着铜绿假单胞菌发酵液的增加而增加，表明 M. aeruginosa 经历了氧化应激。通过基质辅助激光解吸电离飞行时间（MALDI-TOF）成像质谱（IMS）对 M. aeruginosa 及其拮抗剂铜绿假单胞菌的共培养物进行分析，我们揭示了新型种间化感相互作用和竞争分子。我们表明，空间次生代谢物可能介导铜绿假单胞菌抑制 M. aeruginosa 生长的相互作用。此外，我们还揭示了 M. aeruginosa 如何反馈给铜绿假单胞菌，刺激 M. aeruginosa 释放的[D-Asp3]-微囊藻-LR 等次生代谢物。IMS 方法突出了广泛分布的有毒蓝藻与其细菌竞争者之间化感相互作用的重要性。
