The aim of the present study was to isolate and evaluate the diversity of rhizobial and endophytic bacterial strains from undisturbed native rainforests within an iron ore mining site of the Serra Norte de Carajás in the Eastern Brazilian Amazon region to assess their biotechnological utility in reclamation of areas. Experiments were conducted to capture strains from samples of the soil of these forests at the sites Arenito II, Noroeste II, and Sul IV using Macroptilium atropurpureum and Mimosa acutistipula var. ferrea as trap host plants. Only M. atropurpureum nodulated, and the different bacterial strains were isolated from its nodules. There was no difference in the number of nodules among the areas, but the Arenito II bacterial community was the most efficient, indicated by the aboveground biomass production and suitable shoot mass/root mass ratio. Fifty-two (52) bacterial isolates were obtained, distributed in five groups, including nodulating and endophytic bacteria: 32 from Arenito II, 12 from Noroeste II, and 8 from Sul IV. The nodulating Bradyrhizobium genus was common to the three areas, whereas Paraburkholderia was found only in Arenito II. The nodD1 gene was amplified in all the strains of both nodulating genera. Strains of the nodulating genus Methylobacterium were also isolated from the three areas; however, they did not nodulate the host of origin, and their nodD1 gene was not amplified. Endophytic strains were also isolated from the genera Paenibacillus, Pantoea, and Leifsonia in Arenito II, Leifsonia in Noroeste I, and Paenibacillus in Sul IV. The greater nodulation and rhizobial and endophytic bacterial diversity observed in Arenito II were probably due to the more suitable edaphic properties of the area. The isolated strains were incorporated in the collection of the Department of Soil Science of UFLA and will be investigated in relation to their symbiotic characteristics with native host plants, as well as their ability to perform other biological processes.

本研究的目的是分离和评估巴西东部亚马逊地区北塞拉卡拉哈斯铁矿石采矿场内未受干扰的原生雨林中根瘤菌和内生细菌菌株的多样性，以评估其在开垦地区的生物技术效用。进行了实验，使用Macroptilium atropurpureum和Mimosa acutistipula var. 从 Arenito II、Noroeste II 和 Sul IV 地点的这些森林的土壤样本中捕获菌株。铁线蕨作为诱捕寄主植物。只有M. atropurpureum结瘤，并且从其结瘤中分离出不同的菌株。各区域的根瘤数量没有差异，但从地上生物量产量和合适的地上部质量/根质量比来看，Arenito II 细菌群落是最有效的。获得了五十二 (52) 株细菌分离株，分布在五组中，包括结瘤细菌和内生细菌：32 株来自 Arenito II，12 株来自 Noroeste II，8 株来自 Sul IV。结瘤慢生根瘤菌属在这三个地区很常见，而Paraburkholderia只在 Arenito II 发现。 nodD1基因在两个结瘤属的所有菌株中均得到扩增。结瘤甲基杆菌属菌株也从这三个地区分离出来；然而，它们并没有在原始宿主上形成结瘤，并且它们的nodD1基因也没有被扩增。还从Arenito II 中的类芽孢杆菌属、泛菌属和Leifsonia 属、Noroeste I 中的Leifsonia属和Sul IV 中的类芽孢杆菌属中分离出内生菌株。 在 Arenito II 中观察到的更大的结瘤以及根瘤菌和内生细菌多样性可能是由于该地区更适合的土壤特性。这些分离的菌株已被纳入佛罗里达大学洛杉矶分校土壤科学系的收藏，并将对其与本地寄主植物的共生特性以及它们执行其他生物过程的能力进行研究。