Pantoea graminicola sp. nov., a Gram-negative bacterium isolated from sweet corn (Zea mays L.) in the USA

TL;DR

Scientists discovered a new species of bacteria, Pantoea graminicola, from sweet corn plants in Florida, which could impact agriculture.

Contribution

The discovery of Pantoea graminicola, a new bacterial species with distinct genetic and phenotypic traits.

Findings

The new species was identified through phylogenetic, genomic, and biochemical analyses.

Pantoea graminicola has unique substrate utilization and distinct DNA characteristics.

The new species may play a role in sweet corn disease and requires further agricultural study.

Abstract

In 2024, bacterial strains KXB24, KXB25 and KXB45 were isolated from sweet corn (Zea mays L.) plants exhibiting foliar chlorosis and streaking, typical symptoms of bacterial infection, in the Everglades Agricultural Area in Florida, USA. A polyphasic taxonomic study was conducted on these strains. Phylogenetic analysis of 16S rRNA gene sequences, whole-genome comparisons and biochemical characterization confirmed that the isolates belong to the Pantoea genus. The Biolog Gen III MicroPlate system identified substrate utilization profiles that were unique to these strains, distinguishing them from closely related Pantoea species. The strain KXB24 showed positive utilization of d-serine, γ-amino-butyric acid, citric acid and other compounds. On nutrient agar, KXB24, colonies are circular, smooth, convex and yellow and do not produce fluorescent pigment on King’s medium B. The DNA G+C content of KXB24 was determined to be 57.0 mol%. Based on phenotypic distinctions, phylogenomics evidence, average nucleotide identity values below 94.26% and digital DNA–DNA hybridization values below 57.9% when compared to type strains of recognized Pantoea species, we propose Pantoea graminicola sp. nov., with KXB24T (=NCPPB 4802T=LMG 33887T) as the type strain. This discovery enriches the current understanding of Pantoea species and calls for further research into the potential role of P. graminicola in sweet corn disease aetiology and its broader agricultural impacts.

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