de Araujo Ademir Sergio Ferreira, Bezerra Walderly Melgaço, Dos Santos Vilma Maria, Rocha Sandra Mara Barbosa, Carvalho Nilza da Silva, de Lyra Maria do Carmo Catanho Pereira, Figueiredo Marcia do Vale Barreto, de Almeida Lopes Ângela Celis, Melo Vania Maria Maciel
Soil Quality Laboratory, Agricultural Science Center, Federal University of Piauí, Teresina, PI, Brazil.
Laboratório de Ecologia Microbiana e Biotecnologia, Federal University of Ceara, Fortaleza, CE, Brazil.
Antonie Van Leeuwenhoek. 2017 Apr;110(4):457-469. doi: 10.1007/s10482-016-0815-1. Epub 2017 Jan 6.
The Cerrado biome in the Sete Cidades National Park, an Ecological Reserve in Northeastern Brazil, has conserved its native biodiversity and presents a variety of plants found in other savannas in Brazil. Despite this finding the soil microbial diversity and community structure are poorly understood. Therefore, we described soil bacterial diversity and distribution along a savanna vegetation gradient taking into account the prevailing environmental factors. The bacterial composition was retrieved by sequencing a fragment of the 16S ribosomal RNA gene. The bacterial operational taxonomic units (OTUs) were assigned to 37 different phyla, 96 classes, and 83 genera. At the phylum level, a core comprised by Proteobacteria, Acidobacteria, Actinobacteria, Firmicutes, Verrucomicrobia and Planctomycetes, was detected in all areas of Cerrado. 'Cerrado stricto sensu' and 'Cerradao' share more similarities between edaphic properties and vegetation and also present more similar bacterial communities, while 'Floresta decidual' and 'Campo graminoide' show the largest environmental differences and also more distinct bacterial communities. Proteobacteria (26%), Acidobacteria (21%) and Actinobacteria (21%) were the most abundant phyla within the four areas. All the samples present similar bacteria richness (alpha diversity) and the observed differences among them (beta diversity) were more related to the abundance of specific taxon OTUs compared to their presence or absence. Total organic C, N and P are the main abiotic factors structuring the bacterial communities. In summary, our findings show the bacterial community structure was clearly different across the Cerrado gradient, but that these environments share a bacterial phylum-core comprising Proteobacteria, Acidobacteria, Actinobacteria, Verrucomicrobia and Planctomycetes with other Brazilian savannas.
位于巴西东北部生态保护区塞特西达德国家公园内的塞拉多生物群落，保护了其原生生物多样性，并拥有巴西其他稀树草原中发现的多种植物。尽管有这一发现，但土壤微生物多样性和群落结构仍知之甚少。因此，我们考虑到主要的环境因素，描述了沿稀树草原植被梯度的土壤细菌多样性和分布。通过对16S核糖体RNA基因的一个片段进行测序来获取细菌组成。细菌操作分类单元（OTU）被归为37个不同的门、96个纲和83个属。在门的水平上，在塞拉多的所有区域都检测到了由变形菌门、酸杆菌门、放线菌门、厚壁菌门、疣微菌门和浮霉菌门组成的核心菌群。“狭义塞拉多”和“塞拉多原始森林”在土壤性质和植被之间有更多相似之处，并且也呈现出更相似的细菌群落，而“落叶林”和“禾本科草原”表现出最大的环境差异，细菌群落也更独特。变形菌门（26%）、酸杆菌门（21%）和放线菌门（21%）是这四个区域中最丰富的门。所有样本呈现出相似的细菌丰富度（α多样性），它们之间观察到的差异（β多样性）与特定分类单元OTU的丰度相比与其存在与否更相关。总有机碳、氮和磷是构建细菌群落的主要非生物因素。总之，我们的研究结果表明，整个塞拉多梯度上的细菌群落结构明显不同，但这些环境与巴西其他稀树草原共享一个由变形菌门、酸杆菌门、放线菌门、疣微菌门和浮霉菌门组成的细菌门核心菌群。
