Comparison of prokaryotic communities among fields exhibiting different disinfestation effects by anaerobic soil disinfestation

Anaerobic soil disinfestation (ASD) is a chemical-independent fumigation method used for reducing the abundance of pathogens at soil depths of <40 cm. However, its disinfestation efficiency is unstable under field conditions. The microbial community reflects the soil environment and is a good indicator of soil health. Therefore, soil with a good disinfestation efficiency may have a unique microbial community. The aim of the present study was to compare the prokaryotic communities among soils obtained from 17 geographically different greenhouses that experienced tomato bacterial wilt but exhibited different disinfestation efficiencies after ASD treatment with the same substrate. In the present study, soil prokaryotic communities in the field, which indicate difference in disinfestation effects after ASD treatment among several fields, were compared using next-generation sequencing. The prokaryotic communities in the fields showing different disinfestation effects were roughly separated into sampling fields. The relative abundances of Betaproteobacteria and Clostridia were significantly increased in well-disinfested fields. Overall, 25 operational taxonomic units (OTUs) were specifically increased in various well-disinfested soils and 18 OTUs belonged to phylogenetically diversified Clostridia. Other OTUs belonged to aerobic bacteria and were not previously detected in sample collected from ASD-treated fields. The results showed that the changes to the prokaryotic communities did not affect ASD efficiency, whereas changes in the abundance of specific microbes in the community were related to disinfestation.