Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing, China/Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China.
College of Pharmacy, Hunan University of Traditional Chinese Medicine, Hunan, China.
Sci Rep. 2023 Mar 31;13(1):5272. doi: 10.1038/s41598-023-32337-6.
The growth of endophytic bacteria is influenced by the host plants and their secondary metabolites and activities. In this study, P. megaterium P-NA14 and P. megaterium D-HT207 were isolated from potato tuber and dendrobium stem respectively. They were both identified as Priestia megaterium. The antimicrobial activities and metabolites of both strains were explored. For antimicrobial activities, results showed that P. megaterium P-NA14 exhibited a stronger inhibition effect on the pathogen of dendrobium, while P. megaterium D-HT207 exhibited a stronger inhibition effect on the pathogen of potato. The supernatant of P. megaterium P-NA14 showed an inhibition effect only on Staphylococcus aureus, while the sediment of P. megaterium D-HT207 showed an inhibition effect only on Escherichia coli. For metabolomic analysis, the content of L-phenylalanine in P. megaterium P-NA14 was higher than that of P. megaterium D-HT207, and several key downstream metabolites of L-phenylalanine were associated with inhibition of S. aureus including tyrosine, capsaicin, etc. Therefore, we speculated that the different antimicrobial activities between P. megaterium P-NA14 and P. megaterium D-HT207 were possibly related to the content of L-phenylalanine and its metabolites. This study preliminarily explored why the same strains isolated from different hosts exhibit different activities from the perspective of metabolomics.
内生细菌的生长受宿主植物及其次生代谢物和活性的影响。本研究从马铃薯块茎和石斛茎中分别分离到巨大芽孢杆菌 P-NA14 和巨大芽孢杆菌 D-HT207，均鉴定为巨大芽孢杆菌。本研究探索了两株菌的抗菌活性和代谢产物。在抗菌活性方面，结果表明，巨大芽孢杆菌 P-NA14 对石斛病原菌的抑制作用较强，而巨大芽孢杆菌 D-HT207 对马铃薯病原菌的抑制作用较强。巨大芽孢杆菌 P-NA14 的上清液仅对金黄色葡萄球菌表现出抑制作用，而巨大芽孢杆菌 D-HT207 的沉淀物仅对大肠杆菌表现出抑制作用。代谢组学分析结果表明，巨大芽孢杆菌 P-NA14 中 L-苯丙氨酸的含量高于巨大芽孢杆菌 D-HT207，L-苯丙氨酸的几个关键下游代谢物与金黄色葡萄球菌的抑制作用有关，包括酪氨酸、辣椒素等。因此，我们推测巨大芽孢杆菌 P-NA14 和巨大芽孢杆菌 D-HT207 之间不同的抗菌活性可能与 L-苯丙氨酸及其代谢物的含量有关。本研究从代谢组学的角度初步探讨了同一菌株从不同宿主中分离出来为何表现出不同的活性。
