Lee Jueun, Jung Won-Kwon, Ahsan S M, Jung Hee-Young, Choi Hyong Woo
Department of Plant Medicals, Andong National University, Andong, Republic of Korea.
Gyeongsangbuk-do Agricultural Research & Extension Services, Daegu, Republic of Korea.
Front Microbiol. 2024 Nov 21;15:1493430. doi: 10.3389/fmicb.2024.1493430. eCollection 2024.
In this study, we aimed to screen potential antagonistic microorganisms against , the causal agent of fire blight. From 127 unknown bacterial isolates tested, 2 bacterial strains (BCA3 and BCA19) were identified to show distinct antagonistic activity against in agar plate assay. Phylogenetic analysis of the 16s rRNA sequence identified both BCA3 and BCA19 as . Among these BCA19 showed 13.9% stronger antagonistic activity than BCA3. Thus we further characterized antagonistic activity of BCA19. Culture filtrates () of BCA19 significantly inhibited the swimming and swarming motility of . Ethyl acetate and n-butanol extracts of of BCA19 exhibited antibacterial activity in disk diffusion assay. Furthermore, gas chromatography-mass spectrometry analysis of ethyl acetate and n-butanol extracts of of BCA19 identified antibacterial compounds, including indole and hexahydropyrrolo[1,2-a]pyrazine-1,4-dione. Importantly, indole inhibited growth of with IC value of 0.109 ± 0.02 mg/mL (~930.4 μM). Whole genome sequence analysis of BCA 19 revealed gene clusters related with siderphore, andrimid, arylpolyene and carotenoid-type terpene production. This study indicates that BCA19 can be used as a potential biological control agent against .
在本研究中，我们旨在筛选针对火疫病病原菌的潜在拮抗微生物。在测试的127株未知细菌分离物中，有2株细菌菌株（BCA3和BCA19）在琼脂平板试验中表现出对火疫病病原菌的明显拮抗活性。对16s rRNA序列的系统发育分析将BCA3和BCA19均鉴定为[具体菌种未给出]。其中，BCA19的拮抗活性比BCA3强13.9%。因此，我们进一步对BCA19的拮抗活性进行了表征。BCA19的培养滤液显著抑制了火疫病病原菌的泳动和群集运动。BCA19培养滤液的乙酸乙酯和正丁醇提取物在纸片扩散试验中表现出抗菌活性。此外，对BCA19培养滤液的乙酸乙酯和正丁醇提取物进行气相色谱-质谱分析，鉴定出了抗菌化合物，包括吲哚和六氢吡咯并[1,2-a]吡嗪-1,4-二酮。重要的是，吲哚对火疫病病原菌生长的抑制IC值为0.109±0.02 mg/mL（约930.4 μM）。BCA 19的全基因组序列分析揭示了与铁载体、安丝菌素、芳基多烯和类胡萝卜素型萜烯产生相关的基因簇。本研究表明，BCA19可作为一种潜在的针对火疫病病原菌的生物防治剂。
