Characterization and Genomics of Pectinolytic Bacteria Isolated from Soft Rot Symptomatic Produce

Area of Science:

• Plant Pathology
• Microbiology
• Bacteriology

Background:

• Bacterial soft rot causes significant annual crop losses globally.
• Key causal agents include Pectobacterium and Dickeya, with broad host ranges and soil-borne infection routes.
• Recent taxonomic changes complicate the identification of soft rot-causing bacteria.

Purpose of the Study:

• To isolate and characterize pectinolytic bacteria from commercially available produce with soft rot symptoms.
• To investigate the genetic and phenotypic diversity of bacterial soft rot agents.
• To explore potential novel pathogens and their evolutionary relationships.

Main Methods:

• Survey of commercial produce exhibiting soft rot symptoms.
• Isolation of pectinolytic bacteria.
• Genetic and phenotypic characterization of isolates.
• Genomic analysis, including prophage identification.

Main Results:

• Pectobacterium species were frequently isolated, consistent with known soft rot pathogens.
• An isolate from the genus Chryseobacterium was identified as a cause of soft rot symptoms in potatoes.
• Genomic analysis revealed unique prophages in Pectobacterium isolates, potentially influencing their fitness or evolution.
• The Chryseobacterium isolate showed high similarity to Chryseobacterium scophthalmum, a known fish pathogen.

Conclusions:

• Bacterial soft rot is caused by a diverse range of bacteria, including unexpected genera like Chryseobacterium.
• The identification of soft rot pathogens remains challenging due to ongoing taxonomic revisions.
• Prophages may play a role in the adaptation and evolution of Pectobacterium species.
• The Chryseobacterium isolate represents a potential crossover pathogen, expanding the known host range for this genus.