Changes in structural and functional responses of bacterial community under different levels of long-term compost application in paddy soils.

Soils amended for long-term with high levels of compost demonstrated greater abundance of bacterial members of the phylum Bacteroidetes whereas a decreasing trend in the relative abundance of phylum Acidobacteria was noted with increasing levels of compost. Metabolic profiles predicted by PICRUSt demonstrated differences in functional responses of the bacterial community according to the treatments. Soils amended with lower compost levels were characterized by abundance of genes encoding enzymes contributing to membrane transport, cell growth whereas genes encoding enzymes related to protein folding, transcription were enriched in soils amended with high levels of compost. Thus the results of the current study provided an extensive evidence of the influence of different compost levels on bacterial diversity and community structure in paddy soils.