Isolation, characterization and biocontrol of a novel bacteriophage against Ralstonia pseudosolanacearum.

Ralstonia pseudosolanacearum is an increasingly prominent multidrug-resistant phytopathogen. Phages are an effective alternative for treating R. pseudosolanacearum infections. In this study, the phage vB_RsoP_BMB116, which is specific to R. pseudosolanacearum, was isolated from Fujian, China. Electron microscopy revealed that vB_RsoP_BMB116 exhibited a Podoviridae morphotype. The double-stranded DNA genome of vB_RsoP_BMB116 spans 82,991 bp (base pairs) and encodes 119 predicted unidirectionally oriented genes, of which 40 have putative functions assigned, while the remainder encode hypothetical proteins. Genome analysis indicated that vB_RsoP_BMB116 is a new genus. Furthermore, tomato plant experiments conducted in this study demonstrated that vB_RsoP_BMB116 significantly reduces the disease incidence of tomato bacterial wilt induced by R. pseudosolanacearum, thus providing effective experimental support for its potential as a biological control agent against tomato bacterial wilt in agricultural settings. In summary, these results not only expand the genetic repertoire of phages targeting R. pseudosolanacearum but also establish a theoretical and experimental basis for developing phage-mediated biocontrol approaches to manage bacterial wilt in tomato cultivation. KEY POINTS: • The new R. pseudosolanacearum phage vB_RsoP_BMB116 (novel genus) is a key resource for microbiology and biotechnology, aiding new phage therapies and biocontrol agents • Observed via transmission electron microscopy (TEM), the novel phage vB_RsoP_BMB116 belongs to the Podoviridae family • In vitro assays demonstrated that it exhibits significant application potential for the prevention and control of plant bacterial diseases.