Rodrigues Rafael de Souza, Souza Antonia Queiroz Lima de, Barbosa Anderson Nogueira, Santiago Sarah Raquel Silveira da Silva, Vasconcelos Aldenora Dos Santos, Barbosa Roneres Deniz, Alves Thalita Caroline Lima, da Cruz Jeferson Chagas, da Silva Gilvan Ferreira, Bentes Jania Lilia da Silva, Souza Afonso Duarte Leão de
Centro de Apoio Multidisciplinar, Universidade Federal do Amazonas, Manaus, AM 69067-005, Brasil.
Faculdade de Ciências Agrárias, Universidade Federal do Amazonas, Manaus, AM 69067-005, Brasil.
Front Biosci (Elite Ed). 2024 Dec 25;16(4):39. doi: 10.31083/j.fbe1604039.
Actinobacteria are major producers of antibacterial and antifungal metabolites and are growing their search for substances of biotechnological interest, especially for use in agriculture, among other applications. The Amazon is potentially rich in actinobacteria; however, almost no research studies exist. Thus, we present a study of the occurrence and antifungal potential of actinobacteria from the rhizosphere of , a native South American plant and one that is economically useful in the whole of the Amazon.
Among the 64 actinobacteria strains isolated from the rhizosphere of three plants, 20 strains were selected and submitted to dual-culture assays against five important phytopathogenic fungi and morphological and 16S rRNA gene analyses. Two strains, LaBMicrA B270 and B280, were also studied for production curves of metabolic extracts and antifungal activities, including their minimum inhibitory concentration (MIC) against phytopathogenic fungi.
Among the 20 strains, 90% were identified as and 10% as . All the strains showed antagonisms against two or more of five phytopathogens: , , sp., sp., and . spp. strains LaBMicrA B270 and B280 were active against phytopathogens of the guarana plant (). Furthermore, AcOEt/2-propanol 9:1 extract from the 10-day strain LaBMicrA B280 cultured medium presented activity against all the phytopathogens tested, with a minimum inhibitory concentration of 125 μg/mL.
The results revealed various actinomycetes in three rhizospheres of in the Amazon and the high potential of metabolic extracts from some of these bacterial strains against phytopathogenic fungi that destroy numerous crops.
放线菌是抗菌和抗真菌代谢产物的主要生产者，并且正在不断寻找具有生物技术价值的物质，尤其是用于农业等领域。亚马逊地区可能富含放线菌；然而，几乎没有相关研究。因此，我们对一种南美本土植物、在整个亚马逊地区具有经济价值的植物的根际放线菌的存在情况及其抗真菌潜力进行了研究。
从三株植物的根际分离出64株放线菌菌株，从中选取20株，针对五种重要的植物病原真菌进行双培养试验，并进行形态学和16S rRNA基因分析。还对两株菌株LaBMicrA B270和B280的代谢提取物生产曲线和抗真菌活性进行了研究，包括它们对植物病原真菌的最低抑菌浓度（MIC）。
在这20株菌株中，90%被鉴定为，10%被鉴定为。所有菌株对五种植物病原体中的两种或更多种表现出拮抗作用：、、、和。菌株LaBMicrA B270和B280对瓜拉那植物的植物病原体具有活性。此外，来自培养10天的菌株LaBMicrA B280培养基的乙酸乙酯/2-丙醇9:1提取物对所有测试的植物病原体均有活性，最低抑菌浓度为125μg/mL。
结果揭示了亚马逊地区三株植物根际中的多种放线菌，以及其中一些细菌菌株的代谢提取物对破坏多种作物的植物病原真菌具有很高的潜力。
