The metaphenome of a calaminiferous soil

Abstract

The aim of the present research was to determine the metaphenome (the expressed microbial functions) of a calaminiferous soil mostly contaminated with Zn and Pb. For that, three 'omics approaches were combined using soil samples: shotgun metagenomics (MG), metatranscriptomics (MT) and shotgun metaproteomics (MP). Results show that several indexes of bacterial diversity were significantly reduced. The soil was dominated by Acidobacteria, Chloroflexi and Gemmatimonadetes. Although many of the species were not identified, the mean percentages of reads for Candidatus_Solibacter, Bryobacter, Rhodomicrobium and Niastella were significantly more elevated in the contaminated soil when compared to a control soil. For functionality, the identified proteins were classified in 28 functional SEED categories. The MG approach detected many genes that may be used to degrade various types of organic materials, among which chitin, N-acetylglucosamine, cellulose and glycogen. This suggests that the important carbon cycle functions of the heterotrophic communities are maintained in the soil. For metal resistance, the most abundant proteins were P-type ATPases efflux systems.