The Microbiome of Brazilian Mangrove Sediments as Revealed by Metagenomics

Abstract

Here we embark in a deep metagenomic survey that revealed the taxonomic and potential metabolic pathways aspects of mangrove sediment microbiology. The extraction of DNA from sediment samples and the direct application of pyrosequencing resulted in approximately 215 Mb of data from four distinct mangrove areas (BrMgv01 to 04) in Brazil. The taxonomic approaches applied revealed the dominance of Deltaproteobacteria and Gammaproteobacteria in the samples. Paired statistical analysis showed higher proportions of specific taxonomic groups in each dataset. The metabolic reconstruction indicated the possible occurrence of processes modulated by the prevailing conditions found in mangrove sediments. In terms of carbon cycling, the sequences indicated the prevalence of genes involved in the metabolism of methane, formaldehyde, and carbon dioxide. With respect to the nitrogen cycle, evidence for sequences associated with dissimilatory reduction of nitrate, nitrogen immobilization, and denitrification was detected. Sequences related to the production of adenylsulfate, sulfite, and H2S were relevant to the sulphur cycle. These data indicate that the microbial core involved in methane, nitrogen, and sulphur metabolism consists mainly of Burkholderiaceae, Planctomycetaceae, Rhodobacteraceae, and Desulfobacteraceae. Comparison of our data to datasets from soil and sea samples resulted in the allotment of the mangrove sediments between those samples. The results of this study add valuable data about the composition of microbial communities in mangroves and also shed light on possible transformations promoted by microbial organisms in mangrove sediments.

Bacterial Diversity of Mangrove Rhizosphere Soil - Gulf of Khambhat, Gujarat, India

“…Out of ten bacterial species, 9 species occurred at location of Purna estuaries, whereas 5, 4 and 5 species occurred at location of Ghogha coast, Dahej coast and Dumas beach respectively ( Table 2). The range of microorganisms are known to occur in the mangrove forest ecosystem, although these differ as to biogeography and their location of habitats with many factors such as pH, temperature, salinity, availability of nutrients, depth, verities of substrate, level of contamination and anthropogenic activities effecting microbial communities composition and species occurrences [4], [13]. Total bacterial counts in mangrove coastal water and mangrove soils ranged from 2.2 x 10 4 to 7.1 x 10 5 CFU/ml and 6.6…”

“…Mangrove ecosystems support a greatdiversity of life forms including flora and fauna. They are most productive and play a dynamic role as a most important primary producer within coastal and estuarine environment.In mangrove rhizosphere soil, the microorganisms play a major role in the productivity, environment recovery and conservation, where they participate in the biogeochemical cycles and provide nutritional sources to the plant and animals [3], [4]. The free living bacteria were reported to have significant role in the carbon, sulfur, nitrogen and phosphorous cycles in mangrove forest [5] and participants in formation of detritus in the mangrove ecosystems [6].The bacteria from mangrove soil possess unique biotechnological potentials like nitrogen fixation, phosphate solubilization and sulfur oxidation as well as cellulose degradation [7].…”

Descrição da comunidade microbiana ativa em solos de manguezais por metagenômica e metatranscriptômica

“…A anotação baseada no banco de dados KEGG indica a presença de funções essenciais para a capacidade de competição da comunidade microbianas que habitam os solos de manguezais, como, por exemplo, genes relacionados com metabolismo de vitaminas e cofatores, transporte via membrana, metabolismo de aminoácidos, metabolismo de energia e metabolismo de carboidratos (MURÍNOVÁ et al, 2014;ANDREOTE et al, 2012). …”

“…Foi encontrado grande número de sequências relacionadas com genes envolvidos com a imobilização e mineralização do nitrogênio assim como genes envolvidos com transformações minerais deste elemento (Figura 6A). O balanço entre essas vias é influenciado fortemente pelas condições ambientais, tais como temperatura, oxigênio, disponibilidade de nitrato e conteúdo de matéria orgânica nos solos (GOMES et al, 2008;ANDREOTE et al, 2012).…”

“…Trabalhos tem indicado Deltaproteobacteria como uma importante classe com grupos de microrganismos fixadores de nitrogênio em manguezais , inclusive com unidades taxonômicas operacionais (sigla em inglês " T s") que não se agruparam com nenhum grupo já descrito. Essa classe também é a mais dominante no ambiente de manguezais com a capacidade de reduzir o sulfato, composto abundante nestas áreas (VARON-LOPES et al, 2014;ANDREOTE et al, 2012).…”