Gimranov Emil, Santos João, Regalado Laura, Teixeira Cátia, Gomes Paula, Santos Conceição, Pereira-Dias Leandro
iB(2) Laboratory, Department of Biology, Faculty of Sciences, University of Porto, Portugal; LAQV-REQUIMTE, Department of Biology, Faculty of Sciences, University of Porto, Portugal.
iB(2) Laboratory, Department of Biology, Faculty of Sciences, University of Porto, Portugal.
J Environ Manage. 2025 Feb;374:123942. doi: 10.1016/j.jenvman.2024.123942. Epub 2025 Jan 8.
The emergence of bacterial resistance and the increasing restrictions on the use of agrochemicals are boosting the search for novel, sustainable antibiotics. Antimicrobial peptides (AMPs) arise as a new generation of antibiotics due to their effectiveness at low doses and biocompatibility. We compared the antimicrobial activity of four promising AMPs (CA-M, BP100, RW-BP100, and 3.1) against a collection of notorious phytopathogens, and quantified their impact on plant beneficial bacteria. Plant growth promoters (PGP) and biological control agents (BCA) were also included to study the feasibility of integrating AMPs with bio-based strategies to mitigate diseases impacts and promote crop production. Flow cytometry and fluorescence microscopy revealed that the AMPs' effects on the membrane integrity of both gram-negative and gram-positive strains were time- and concentration-dependent. Bacterial strains were separated into three groups of susceptibility to the AMPs. Group 1 was represented by the most sensitive, gram-negative phytopathogenic belonging to Xanthomonadales and Pseudomonadales and the gram-positive C. michiganensis subsp. michiganensis. Group 2 encompassed bacteria showing intermediate susceptibility, namely P. carotovorum subsp. carotovorum, P. cerasi, both phytopathogens, as well as the plant growth promoters P. fluorescens and P. putida. Finaly, Group 3 was represented by the bacteria with the lowest susceptibility to AMPs. It included beneficial bacteria (B. zhangzhouensis, B. subtilis, B. safensis, P. azotoformans), a phytopathogen (R. solanacearum), and a strain reported as able to act as both (P. aeruginosa). This work demonstrates that the minimum inhibitory concentrations (MICs) needed to act against the beneficial Bacillus and Pseudomonas strains were higher than those needed to produce bacteriostatic or bactericidal effects on the phytopathogens tested, hence supporting that these AMPs might be environmentally safe antibiotics with low likeliness of disrupting the beneficial microbial communities. The possibility of mixing these AMPs with BCA/PGP, in a combined biocontrol strategy, is also discussed.
细菌耐药性的出现以及对农用化学品使用限制的增加，正在推动人们寻找新型、可持续的抗生素。抗菌肽（AMPs）因其低剂量有效性和生物相容性而成为新一代抗生素。我们比较了四种有前景的抗菌肽（CA-M、BP100、RW-BP100和3.1）对一系列臭名昭著的植物病原体的抗菌活性，并量化了它们对植物有益细菌的影响。还纳入了植物生长促进剂（PGP）和生物防治剂（BCA），以研究将抗菌肽与生物基策略相结合以减轻疾病影响和促进作物生产的可行性。流式细胞术和荧光显微镜显示，抗菌肽对革兰氏阴性和革兰氏阳性菌株膜完整性的影响具有时间和浓度依赖性。细菌菌株被分为对抗菌肽敏感性的三组。第1组以最敏感的革兰氏阴性植物病原体为代表，它们属于黄单胞菌目和假单胞菌目，以及革兰氏阳性的密歇根棒杆菌密歇根亚种。第2组包括敏感性中等的细菌，即胡萝卜软腐果胶杆菌胡萝卜软腐亚种、樱桃假单胞菌，这两种都是植物病原体，以及植物生长促进剂荧光假单胞菌和恶臭假单胞菌。最后，第3组以对抗菌肽敏感性最低的细菌为代表。它包括有益细菌（漳州芽孢杆菌、枯草芽孢杆菌、沙福芽孢杆菌、固氮假单胞菌）、一种植物病原体（茄科雷尔氏菌）以及一种被报道既能致病又有益的菌株（铜绿假单胞菌）。这项工作表明，对有益芽孢杆菌和假单胞菌菌株产生作用所需的最低抑菌浓度（MICs）高于对所测试的植物病原体产生抑菌或杀菌作用所需的浓度，因此支持这些抗菌肽可能是对环境安全的抗生素，扰乱有益微生物群落的可能性较低。还讨论了在联合生物防治策略中将这些抗菌肽与生物防治剂/植物生长促进剂混合的可能性。
