High-throughput sequencing reveals that tree species selected highly diverse fungal communities harboring different lignocellulolytic enzymes. Illumina MiSeq sequencing of fungal functional genes

Forest ecosystems play an essential ecological function by storing up to two thirds of the terrestrial organic carbon. Most of forest soil organic carbon originate from plant litter. Therefore, degradation of plant biomass is an essential process for the proper functioning of forest soils and the terrestrial carbon cycle. Soil microorganisms and more precisely saprotrophic fungi are the principal actors in this process as they produce a wide range of extracellular enzymes involved in the decomposition of the main plant cell wall polymers. Structure and composition of litter is different depending on tree species and affect diversity and composition of soil fungal communities. We therefore hypothesized that fungal communities selected by different tree species express specific lignocellulolytic enzymes. In the present survey, we simultaneously analyzed the effect of tree species (beech vs spruce) on the taxonomic composition of the active fungal community in soils and on the diversity of expressed fungal genes encoding three major families of Carbohydrate-Active Enzymes (CAZymes) involved in the degradation of the lignocellulose (GH7 [Cellulases], GH11 [Hemicellulases] and AA2 [Class II Peroxidases active on lignin]). Amplicons were generated for GH7, GH11, AA2 and EF1a gene family with specific fungal degenerated primers. All amplicons were sequenced by high-throughput sequencing using Illumina Miseq technology.