Biofilm formation ability of Paenibacillus polymyxa and Paenibacillus macerans and their inhibitory effect against tomato bacterial wilt

摘要

The potential of biofilm formation?of 16?Paenibacillus?strains?and?their?inhibitory effect against?bacterial wilt of tomato seedlings were examined in this study. The crystal violet assay indicated that all strains?of?Paenibacillus?except strain MB02-1202 formed biofilm after 96 and 144 h of incubation while there was not significant difference in biofilm formation between strains of?Paenibacillus polymyxa?and strains of?Paenibacillus macerans. However, the increase level of biofilm formation was associated with the increase of the incubation time and the initial inoculum density. In addition, allPaenibacillus?strains except strain?MB02-428 reduced wilt incidence in tomato seedlings inoculated with?Ralstonia solanacearum?while?the?cell numbers?of?R.?solanacearum?inrhizosphere soil?was reduced by all?Paenibacillus?strains compared to the pathogen control. In general, most strains?of?Paenibacillus?were able to both form biofilm and protect tomato seedlings from bacterial wilt, indicating that biofilm formation may play an important role in the biocontrol of?Paenibacillus. This is first study regarding the relationship between?in vitro?biofilm formation ability of?Paenibacillus?strains and their inhibitory activity against?R. solanacearum.