Exploring the potential of Pseudomonas soli as a biocontrol agent

TADEO E. GALVAN; VALERIA P. CONFORTE; MALAMUD FLORENCIA; NATALIA MIELNICHUK; LAILA TOUM; ADRIAN A. VOJNOV; PABLO MARCELO YARYURA; M ISABEL BIANCO

Córdoba

Congreso; XIX Congreso de la Sociedad Argentina de Microbiología General; 2024

SAMIGE

Xanthomonas vesicatoria is one of the causal agents of bacterial spot in tomato (Solanum lycopersicum), a disease that causes significant yield and economic losses. Bacterial spot is currently managed with copper-based agrochemicals, which are only partially effective and cause environmental and health problems. Biocontrol methods can help to develop more effective and environmentally friendly strategies to manage this disease. (+)Whole-genome sequencing of bacterial strain VMAP1 and phylogenetic analyses allowed us to identify it as Pseudomonas soli, a scarcely studied species.We isolated VMAP1 from rhizosperic soil of healthy tomato plants and studied its biocontrol properties against X. vesicatoria strain BNM 208.VMAP1 produces proteases and siderophores, moves by swarming, swimming and twitching and does not form biofilm. In vitro, VMAP1 inhibited the growth of BNM 208, but its cell-free supernatant (CFS-AP1) did not.The CFS-AP1 showed in vitro anti-biofilm activity against BNM 208.Foliar spraying of the CFS-AP1 significantly reduced the severity of bacterial spot caused by BNM 208 on tomato plants1. Currently, VMAP1 is the only known P. soli strain with demonstrated biocontrol properties.By ESI-MS, we identified xantholysin A, B and C, extracted from the CFS-AP1.