# Microbacterium chionoecetis sp. nov. and Agrococcus chionoecetis sp. nov.: Novel Gut Bacteria from Red Snow Crab

## TL;DR

Scientists discovered two new bacteria species in the gut of red snow crabs, which could have biotech applications due to their unique properties.

## Contribution

Identification and characterization of two novel bacterial species from the gut of red snow crab with potential biotechnological significance.

## Key findings

- ProA8T and ProA11T are new species in the genera Microbacterium and Agrococcus, respectively.
- Both strains are non-pathogenic and possess biosynthetic genes for resorcinol and ectoine production.
- Genomic and phenotypic data confirm their novelty and distinguish them from related species.

## Abstract

Two yellow-coloured, Gram-stain-positive, oxidase-negative, aerobic, non-motile, and rod-shaped strains, labelled as ProA8T and ProA11T, were isolated from digestive tract of red snow crab (Chionoecetes japonicus). Strain ProA8T grow at temperature range of 15–35°C, while strain ProA11T grow at temperature range of 15–40°C. Phylogenetic and 16S rRNA gene sequence analysis revealed that strains ProA8T and ProA11T belonged to the genera Microbacterium and Agrococcus, respectively. Strain ProA8T was closely affiliated with Microbacterium yannicii JCM 18959T (98.8%) and strain ProA11T was most closely related to Agrococcus baldri IAM 15147T (98.9%). The genome sizes of ProA8T and ProA11T were 4,373,776 bp and 2,665,899 bp, with DNA G+C contents of 70.5% and 70.1%, respectively. The genomic relatedness values of ProA8T and ProA11T with their respective reference strains were <32.0% (for digital DNA–DNA hybridization) and <87.0% (for average nucleotide identity). Biosynthetic gene analysis showed the presence of genes for resorcinol production in ProA8T and ectoine biosynthesis in ProA11T, indicating ecological and biotechnological significance. Virulence analyses determined that strains ProA8T and ProA11T were non-pathogenic to humans, highlighting their safe application in biotechnological field. The major cellular fatty acids reported in ProA8T and ProA11T were anteiso-C15:0, iso-C16:0, and anteiso-C17:0. Overall, the polyphasic taxonomic data suggest that both strains ProA8T and ProA11T represent two novel species within the genera Microbacterium and Agrococcus, respectively. Accordingly, we propose the names Microbacterium chionoecetis sp. nov., with the type strain ProA8T (= KCTC 49861T = JCM 37392T) and Agrococcus chionoecetis sp. nov., with the type strain ProA11T (= KCTC 49958T = JCM 37393T).