铜绿假单胞菌HZ15的生物活性

Bioactivities of Pseudomonas aeruginosa HZ15

摘要:

【背景】 实验室前期自巨网苔蛾幼虫分离所得的铜绿假单胞菌(Pseudomonas aeruginosa) HZ15对烟草黑胫病具有较强拮抗作用，但其余生物活性尚未挖掘。【目的】 通过对菌株HZ15在农业上的生物活性进行探究，旨在为该菌株在农业领域的应用提供理论基础，并为其生物农药开发提供科学依据。【方法】 采用琼脂扩散法、平板对峙、饲喂法、生物测定法、盆栽和大田试验等探究菌株HZ15的抑菌、促生、杀虫及对黑麦草的除草活性。【结果】 菌株HZ15对4种植物病原细菌具有较强的抑菌活性，对11种植物病原真菌的抑制率均达到60%以上，表现出广谱抑菌活性；对烟草青枯病的盆栽试验防效达52.48%，与52%氯尿硫酸铜可溶性粉剂800倍液处理间无显著差异。大田促生试验中，菌株HZ15能够显著增加烟草的叶片数和最大叶面积。此外，该菌及其次生代谢产物对红火蚁和秀丽隐杆线虫均有较强的毒杀作用，其中，上清滤液对红火蚁的毒杀作用最强，而菌液对秀丽隐杆线虫的毒杀能力最好。对黑麦草的除草活性实验表明，菌株HZ15对黑麦草的萌发抑制率达63.80%，并且显著降低了黑麦草的根长、茎长及鲜重。【结论】 铜绿假单胞菌HZ15具有抑菌、促生、杀虫、抑制黑麦草生长的生物活性，在农业和环境管理中具有重要的应用潜力。

Abstract:

[Background] We have discovered that Pseudomonas aeruginosa HZ15 isolated from Macrobrochis gigas has a strong antagonistic effect against tobacco black shank. However, other biological activities of this strain remain to be explored. [Objective] To investigate the bioactivities of strain HZ15 in agriculture and provide a theoretical basis for the application of this strain in agricultural production and the development of biocontrol agents with this strain. [Methods] The agar diffusion method, plate confrontation, feeding method, bioassay, and pot and field experiments were employed to examine the antimicrobial, plant growth-promoting, insecticidal, and herbicidal (against ryegrass) activities of strain HZ15. [Results] Strain HZ15 showcased strong inhibitory activities against four species of plant pathogenic bacteria and the inhibition rates over 60% against 11 species of plant pathogenic fungi, exhibiting a broad antimicrobial spectrum. The pot experiment showed that the strain had a control effect of 52.48% against tobacco bacterial wilt, which was comparable to that of 52% chloroisobromine cyanuric acid·copper sulfate soluble powder diluted by 800 times. The field experiment showed that strain HZ15 significantly increased the number of tobacco leaves and the maximum leaf area. In addition, both strain HZ15 and its secondary metabolites exhibited strong toxicity against Solenopsis invicta and Caenorhabditis elegans, with the supernatant and bacterial culture showing the strongest toxic effects on S. invicta and C. elegans, respectively. In addition, strain HZ15 inhibited the germination of ryegrass by 63.80% and significantly reduced the root length, stem length, and fresh weight of ryegrass. [Conclusion] P. aeruginosa HZ15 possesses antimicrobial, plant growth-promoting, insecticidal, and ryegrass growth-inhibiting activities, demonstrating significant potential for application in agriculture and environmental management.