Description of Microbacterium luteum sp. nov., Microbacterium cremeum sp. nov., and Microbacterium atlanticum sp. nov., three novel C50 carotenoid producing bacteria

• Published in: The journal of microbiology Vol. 59; no. 10; pp. 886 - 897
• Main Authors: Xie, Fuquan, Niu, Siwen, Lin, Xihuang, Pei, Shengxiang, Jiang, Li, Tian, Yun, Zhang, Gaiyun
• Format: Journal Article
• Language: English
• Published: Seoul The Microbiological Society of Korea 01.10.2021; Springer Nature B.V; 한국미생물학회
• Subjects: Base Composition; Biomedical and Life Sciences; Carotenoids; Carotenoids - chemistry; Carotenoids - metabolism; Deoxyribonucleic acid; DNA; DNA, Bacterial - genetics; Dry cells; Fatty Acids - chemistry; Fatty Acids - metabolism; Genomes; Hybridization; Life Sciences; Mevalonic acid; Microbacterium; Microbacterium - classification; Microbacterium - genetics; Microbacterium - isolation & purification; Microbacterium - metabolism; Microbial Systematics and Evolutionary Microbiology; Microbiological strains; Microbiology; Morphology; New species; Nucleotide sequence; Nucleotides; Phosphates; Phylogeny; RNA, Ribosomal, 16S - genetics; rRNA 16S; Seawater - microbiology; Strains (organisms); Taxonomy; 생물학; decaprenoxanthin; C50 carotenoids production; sarcinaxanthin; isoprenoid biosynthetic pathway; C50 carotenoids biosynthetic pathway; Microbacterium
• ISSN: 1225-8873; 1976-3794
• DOI: 10.1007/s12275-021-1186-5

We have identified three Microbacterium strains, A18JL200 T , NY27 T , and WY121 T , that produce C50 carotenoids. Taxonomy shows they represent three novel species. These strains shared < 98.5% 16S rRNA gene sequence identity with each other and were closely related to Microbacterium aquimaris JCM 15625 T , Microbacterium yannicii JCM 18959 T , Microbacterium ureisolvens CFH S00084 T , and Microbacterium hibisci CCTCC AB 2016180 T . Digital DNA-DNA hybridization (dDDH) values and average nucleotide identity (ANI) showed differences among the three strains and from their closest relatives, with values ranging from 20.4% to 34.6% and 75.5% to 87.6%, respectively. These values are below the threshold for species discrimination. Both morphology and physiology also differed from those of phylogenetically related Microbacterium species, supporting that they are indeed novel species. These strains produce C50 carotenoids (mainly decaprenoxanthin). Among the three novel species, A18JL200 T had the highest total yield in carotenoids (6.1 mg/L or 1.2 mg/g dry cell weight). Unusual dual isoprenoid biosynthetic pathways (methylerythritol phosphate and mevalonate pathways) were annotated for strain A18JL200 T . In summary, we found strains of the genus Microbacterium that are potential producers of C50 carotenoids, but their genome has to be investigated further.