Metagenomic characterization of soil microbial communities in the Luquillo experimental forest (Puerto Rico) and implications for nitrogen cycling

Appl Environ Microbiol. 2021 Apr 9:AEM.00546-21. doi: 10.1128/AEM.00546-21. Online ahead of print.ABSTRACTThe phylogenetic and functional diversity of microbial communities in tropical rainforests, and how these differ from temperate communities remain poorly described but are directly related to the increased fluxes of greenhouse gases such as nitrous oxide (N2O) from the tropics. Towards closing these knowledge gaps, we analyzed replicated shotgun metagenomes representing distinct life zones and an elevation gradient from four locations in the Luquillo Experimental Forest (LEF), Puerto Rico. These soils had a distinct microbial community composition and lower species diversity when compared to temperate grasslands or agricultural soils. In contrast to the overall distinct community composition, the relative abundances and nucleotide sequences of N2O reductases (nosZ) were highly similar between tropical forest and temperate soils. However, respiratory NO reductase (norB) was 2-fold more abundant in the tropical soils, which might be relatable to their greater N2O emissions. Nitrogen fixation (nifH) also showed higher relative abundance in rainforest compared to temperate soils, i.e., 20% vs. 0.1-0.3% of bacterial genomes in each soil type harbored the gene, respectively. Finally, unlike temperate soils, LEF soils showed little stratification with depth in the first 0-30cm, with ∼45% of community composition differences explained solely by location. Collectively, these res...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Source Type: research