| Summary: | <i>Paenibacillus dendritiformis</i> UJA2219 isolated from carrot produces broad-spectrum antibacterial activity. The aim of the present study was to determine the impact of partially-purified cell-culture extracts of strain UJA2219 on the microbial load and bacterial diversity of a homemade vegetable puree. The puree was challenged with an overnight culture of strain UJA2219 or with cultured broth extracts partially purified by cation exchange (CE) chromatography or reversed-phase (RP) chromatography and incubated for 7 days at temperatures of 4 °C or 25 °C. The best results were obtained at 25 °C with the RP extract, decreasing counts of the presumptive <i>Enterobacteriaceae</i> below detectable levels. The bacterial diversity of control and treated puree was studied by Illumina paired-end sequencing, using DNA extracted from the puree samples incubated at 25 °C for 24 h. The controls and the puree inoculated with the UJA2219 strain showed an almost-identical bacterial diversity profile, with <i>Pseudomonadota</i> (mainly Fam. <i>Pseudomonadaceae</i> -gen. <i>Pseudomonas</i>- and <i>Enterobacteriace</i> as the most abundant groups). The greatest differences in bacterial diversity were obtained in the puree treated with RP extract, showing a decrease in the relative abundance of <i>Pseudomonadota</i> (especially gen. <i>Pseudomonas</i>) and an increase of <i>Bacillota</i> (mainly of the genera <i>Bacillus</i>, <i>Enterococcus</i> and <i>Lactococcus</i>). Results from the study suggest that the antimicrobial preparations from strain UJA2219 have a potential for application in food biopreservation.
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