Rossellomorea contaminans sp. nov., a Novel Carotenoid-Producing Contaminant Bacterium Isolated from the Semi-Finished Catheters

Abstract The novel bacterial species Rossellomorea contaminans sp. nov. (strain FM0494T) was isolated as a contaminant from semi-finished catheters. This product originated from a medical supplies production workshop in Guangdong, China. Strain FM0494T consisted of gram-positive, aerobic, and non-motile rods with terminal oval endospores, non-flagellated rods and non-swollen sporangia whose cells formed yellow, raised, opaque and butyrous colonies. Growth was observed at a temperature range of 10–45°C, a pH range of 6.0–8.0, and 0–15% NaCl (w/v) was tolerated, indicating optimal growth conditions on tryptic soy agar (TSA) plates at pH 7.0 and 37°C for 24 h. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain FM0494T shared the highest similarity of 99.25% to Rossellomorea arthrocnemi EAR8T and clusters within the genus Rossellomorea. The average nucleotide identity (ANI) and the digital DNA–DNA hybridization (dDDH) values between strain FM0494T and type strains of the genus Rossellomorea were all below the respective thresholds of ANI and dDDH for species delimitation. Genome analyses revealed that FM0494T possesses carotenoid biosynthetic genes, siderophore biosynthesis pathways, surfactin, LAP (Lantibiotic and other peptide synthetase) and T3PKS (Type III polyketide synthase) clusters. Comparative investigations of phenotype and phylogenomics indicate that strain FM0494T is a novel representative of the genus Rossellomorea, and the name Rossellomorea contaminans sp. nov. is proposed. The type strain is FM04394T (=KCTC 43714T = GDMCC 1.4634T). This study represents the first report of a Rossellomorea strain isolated as a contaminant from an industrial environment. This study further investigates the mechanisms employed by strain FM0494T to adapt to the intricate conditions of the production environment, offering novel insights for the prevention and control of industrial microbial contaminants.