AUTHOR=Jiang Lingmin , Jeon Doeun , Kim Jueun , Lee Chul Won , Peng Yuxin , Seo Jiyoon , Lee Ju Huck , Paik Jin Hyub , Kim Cha Young , Lee Jiyoung 

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

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.733612

DOI=10.3389/fmicb.2021.733612

ISSN=1664-302X

ABSTRACT=<p>A novel endophytic bacterial strain, designated GR-TSA-9<sup>T</sup>, was isolated from surface-sterilized grape (<italic>Vitis vinifera</italic> L.). 16S rRNA gene sequence analyses showed that the isolate was grouped within the genus <italic>Brevundimonas</italic>, displaying the highest similarity with <italic>Brevundimonas lenta</italic> DS-18<sup>T</sup> (97.9%) and <italic>Brevundimonas kwangchunensis</italic> KSL-102<sup>T</sup> (97.8%) and less than 97.5% similarity with other members of <italic>Brevundimonas</italic>. The strain GR-TSA-9<sup>T</sup> 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 (&gt;10% of the total) were C<sub>16:0</sub> (14.2%) and summed feature 8 (C<sub>18:1</sub>ω7<italic>c</italic> and/or C<sub>18:1</sub>ω6c, 65.6%). The polar lipids present in the strain were phosphoglycolipids, phosphatidylglycerol, 1,2-di-<italic>O-</italic>acyl-3-O-[<sc>d</sc>-glucopyranosyl-(1→4)-α-<sc>d</sc>-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<sup>T</sup> and <italic>B. lenta</italic> DS-18<sup>T</sup> 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<sup>T</sup> produced a brown melanin-like pigment in the presence of <sc>L</sc>-tyrosine-containing media. The highest pigment production (0.19g/L) was observed in tryptic soy broth with 1.0mg/ml <sc>L</sc>-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<sup>T</sup> cells could protect the cells against UVC exposure. The phylogenetic, genomic, phenotypic, and chemotaxonomic features indicated that strain GR-TSA-9<sup>T</sup> represents a novel melanin-producing species of <italic>Brevundimonas</italic>. The type strain was GR-TSA-9<sup>T</sup> (KCTC 82386<sup>T</sup>=CGMCC 1.18820<sup>T</sup>).</p>