# The Factors Involved in Plant–Insect–Microbe Interactions Expanded: Genome Analysis and Description of Frigoribacterium adelgis sp. nov

## TL;DR

Scientists discovered a new species of bacteria, Frigoribacterium adelgis, found in insects on fir trees, which may play a role in breaking down plant material and adapting to harsh environments.

## Contribution

Identification and genomic characterization of a new bacterial species, Frigoribacterium adelgis, and its potential roles in plant-insect-microbe interactions.

## Key findings

- The bacteria encode enzymes that can degrade plant polysaccharides like cellulose and xylan.
- Genomic islands in the bacteria's DNA suggest adaptation to environmental stressors and expanded metabolic functions.
- A new species, Frigoribacterium adelgis, was proposed based on genomic and phenotypic analyses.

## Abstract

Actinobacteria of the genus Frigoribacterium were isolated from adelgid Adelges (Aphrastasia) pectinatae collected from a Korean fir tree. Genomic analyses revealed that these bacteria encode a range of factors that may be involved in the interactions among Frigoribacterium strains, adelgids and/or conifers. Secreted carbohydrate‐active enzymes were identified in the genomes, which allow these bacteria to degrade plant polysaccharides such as cellulose, xylan, pectin and mannan, the main hemicellulose component of softwood. The degradation potential of insect cuticles was investigated, and secreted chitinases belonging to the GH18 family were predicted to be present in the genomes. However, no phenotypic chitinolytic activity was detected. The potential interactions between these bacterial strains and either plants or insects were assessed, resulting in a few high‐scoring hits. The related Frigoribacterium genomes were compared, revealing several unique features, such as numerous orthologous gene clusters specific to these strains and five biosynthetic gene clusters. Ten genomic islands were predicted in the genomes of the adelgid‐associated strains, which contained genes responsible for adapting to environmental changes, resisting heavy metals and expanding metabolic capabilities. We propose a new species, Frigoribacterium adelgis, belonging to the genus Frigoribacterium, based on these results.

Aerobic Actinobacteria belonging to the genus Frigoribacterium were isolated from adelgid Adelges (Aphrastasia) pectinatae collected from a Korean fir tree.Genomic analysis showed that these bacteria encode a range of factors that may be involved in the interactions between Frigoribacterium strains, adelgids and/or Korean fir trees.A few distinctive characteristics of the adelgid‐associated Frigoribacterium sp. strains were determined. Based on these results, a new species Frigoribacterium adelgis was proposed.

Aerobic Actinobacteria belonging to the genus Frigoribacterium were isolated from adelgid Adelges (Aphrastasia) pectinatae collected from a Korean fir tree.

Genomic analysis showed that these bacteria encode a range of factors that may be involved in the interactions between Frigoribacterium strains, adelgids and/or Korean fir trees.

A few distinctive characteristics of the adelgid‐associated Frigoribacterium sp. strains were determined. Based on these results, a new species Frigoribacterium adelgis was proposed.