Pyomelanin-Producing Brevundimonas vitisensis sp. nov., Isolated From Grape (Vitis vinifera L.)

• Published in: Frontiers in microbiology Vol. 12; p. 733612
• Main Authors: Jiang, Lingmin, Jeon, Doeun, Kim, Jueun, Lee, Chul Won, Peng, Yuxin, Seo, Jiyoon, Lee, Ju Huck, Paik, Jin Hyub, Kim, Cha Young, Lee, Jiyoung
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 14.10.2021
• Subjects: endophytic bacterium; melanin production; Microbiology; natural pigments; phylogenetic analysis; strain GR-TSA-9T
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2021.733612

A novel endophytic bacterial strain, designated GR-TSA-9 T , was isolated from surface-sterilized grape ( Vitis vinifera L.). 16S rRNA gene sequence analyses showed that the isolate was grouped within the genus Brevundimonas , displaying the highest similarity with Brevundimonas lenta DS-18 T (97.9%) and Brevundimonas kwangchunensis KSL-102 T (97.8%) and less than 97.5% similarity with other members of Brevundimonas . The strain GR-TSA-9 T was a gram negative, rod shaped, facultatively anaerobic, catalase and oxidase positive, and motile bacterium. Its growth occurred at 10–37°C (optimally 25–30°C), at pH 7.0–8.0, and in NaCl 0–1% (optimally 0%). It contained ubiquinone-10 as a respiratory quinone, and the major cellular fatty acids (>10% of the total) were C 16:0 (14.2%) and summed feature 8 (C 18:1 ω7 c and/or C 18:1 ω6c, 65.6%). The polar lipids present in the strain were phosphoglycolipids, phosphatidylglycerol, 1,2-di- O- acyl-3-O-[ d -glucopyranosyl-(1→4)-α- d -glucopyranuronosyl]glycerol, and unidentified lipids (L1, L2, and L4). The strain had one 2,976,716bp circular chromosome with a G+C content of 66.4%. The digital DNA–DNA hybridization value between strain GR-TSA-9 T and B. lenta DS-18 T was 20.9%, while the average nucleotide identity value was 76.7%. In addition, the dDDH and ANI values to other members in this genus, whose genome sequences are available, are less than 21.1 and 77.6%. Genome annotation predicted the presence of some gene clusters related to tyrosine degradation and pyomelanin formation. Strain GR-TSA-9 T produced a brown melanin-like pigment in the presence of L -tyrosine-containing media. The highest pigment production (0.19g/L) was observed in tryptic soy broth with 1.0mg/ml L -tyrosine at 25°C for 6days of culture. Biophysical characterization by ultraviolet (UV)–visible spectroscopy, Fourier-transform infrared spectroscopy, and electrospray ionization mass spectrometry confirmed that the pigment was pyomelanin. Additionally, melanized GR-TSA-9 T cells could protect the cells against UVC exposure. The phylogenetic, genomic, phenotypic, and chemotaxonomic features indicated that strain GR-TSA-9 T represents a novel melanin-producing species of Brevundimonas . The type strain was GR-TSA-9 T (KCTC 82386 T =CGMCC 1.18820 T ).