The families Ruminococcaceae, Lachnospiraceae, and Clostridiaceae are the dominant bacterial groups during reductive soil disinfestation with incorporated plant residues

Abstract

Reductive soil disinfestation (RSD), alternatively called biological soil disinfestation or anaerobic soil disinfestation, is an environmentally friendly method used to control soil-borne diseases. Microorganisms are regarded as the key contributors for RSD; however, there is limited information on the relative importance of these microorganisms, which is essential for understanding the mechanisms underlying RSD. In this study, RSD was performed with four soils in a pot experiment, and the bacterial communities present during the RSD process were detected using MiSeq sequencing based on bacterial 16S rDNA. The results showed that RSD significantly changed the structure of the soil bacterial communities and reduced bacterial richness and diversity. The relative abundance of Firmicutes increased significantly, and the relative abundances of Actinobacteria and Acidobacteria decreased. Ruminococcaceae, Lachnospiraceae, and Clostridiaceae, which belong to Clostridiales within Firmicutes, were the three dominant bacterial families during RSD in most soils. Ruminococcaceae and Lachnospiraceae, rather than Clostridiaceae (previously identified as the key contributor), were strongly related to the pH decrease during RSD, which is considered an indicator for the accumulation of short-chain fatty acids. In addition to these bacterial groups, the families Sphingobacteriales, Bacillales, Burkholderiales, and Bacteroidales were enriched in some RSD-treated soils. In conclusion, the RSD treatment, soil type, and their interactions jointly influenced the bacterial communities and compositions in the RSD-treated soils.