AUTHOR=Wang Shuo , Mu Dashuai , Du Zong-Jun 

TITLE=Persicimonas caeni gen. nov., sp. nov., the Representative of a Novel Wide-Ranging Predatory Taxon in Bradymonadales

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.00698

DOI=10.3389/fmicb.2020.00698

ISSN=1664-302X

ABSTRACT=<p>A novel bacterial strain, designated YN101<sup>T</sup>, was isolated from a marine solar saltern in the coast of Weihai, Shandong Province, China. Strain YN101<sup>T</sup> was Gram-stain negative, facultatively anaerobic, oxidase and catalase negative bacterium with the ability to prey on other microbes. A cross-streaking culture method was utilized to analyze the predatory activity of strain YN101<sup>T</sup>. The results showed strain YN101<sup>T</sup> could prey on various bacteria, either Gram-stain negative or Gram-stain positive. According to the predatory assays, different species in the same genus may behave differently when attacked by strain YN101<sup>T</sup>. The predatory behavior of strain YN101<sup>T</sup> to four typical species was analyzed, and furthermore, predation to <italic>Algoriphagus marinus</italic> am2<sup>T</sup> were quantitatively studied by fluorogenic quantitative PCR, and the gene copies decreased over two magnitudes. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YN101<sup>T</sup> shared the greatest sequence similarity of 93.9% to <italic>Bradymonas sediminis</italic> FA350<sup>T</sup>. The complete genome sequence of strain YN101<sup>T</sup> was 8,047,306 bp in size and the genomic DNA G + C content was 63.8 mol%. The digital DNA-DNA hybridization (dDDH) values and average nucleotide identity (ANI) values between strain YN101<sup>T</sup> and <italic>B. sediminis</italic> FA350<sup>T</sup> were 13.9 and 74.0%. The genetic features showed that the biosynthesis of many important compounds was deficient in genome of strain YN101<sup>T</sup>, which may lead to its predation. Moreover, its genome encoded many genes affiliated with type IV pili, secretion system, membrane proteins and transduction proteins. Similar with myxobacteria and <italic>Bdellovibrio</italic> and like organisms (BALOs), these genes should play important roles in motility, adhesion or virulence to attack prey cells during predation. The predominant polar lipid profile of strain YN101<sup>T</sup> consisted of phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), and one unidentified aminophospholipid (APL). The major cellular fatty acid of strain YN101<sup>T</sup> was iso-C<sub>17:0</sub>, and the sole respiratory quinone was MK-7. Based on the chemotaxonomic, physiological and biochemical characteristics, strain YN101<sup>T</sup> represents a novel species of a novel genus in the family <italic>Bradymonadaceae</italic>, for which the name <italic>Persicimonas caeni</italic> gen. nov., sp. nov. is proposed. The type strain is YN101<sup>T</sup> (=KCTC 72083<sup>T</sup> = MCCC 1H00374<sup>T</sup>).</p>