Psychromonas algicola sp. nov. and Psychromonas algarum sp. nov., two novel bacteria isolated from red macroalgae (Grateloupia sp.)

作者：Si-Jia Fan, Hanzhe Zhang, Bei Pan, Tian-He Liu, De-Chen Lu, Zong‐Jun Du · 发表于：INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY · 年份：2025 · DOI：10.1099/ijsem.0.006903 · 研究领域：Genomics and Phylogenetic Studies、Microbial Community Ecology and Physiology、Probiotics and Fermented Foods

Two Gram-stain-negative and rod-shaped bacteria, designated as RZ5 T and RZ22 T , isolated from a red macroalgae sample, were characterized by a polyphasic approach to clarify their taxonomic position. Strain RZ5 T grew at 4–33 °C (optimum, 25–28 °C), pH 6.5–8.5 (optimum, 7.0–8.0) and in 0.5–5.0% (w/v) NaCl (optimum, 1.0%). Strain RZ22 T grew at 4–28 °C (optimum, 20–25 °C), pH 6.5–8.5 (optimum, 7.0–8.0) and in 2.0–5.0% (w/v) NaCl (optimum, 3.0%). Strain RZ5 T possessed a flagellum and was motile, while strain RZ22 T lacked a flagellum and was non-motile. Phylogenetic analysis based on 16S rRNA gene sequences indicated that both isolates belonged to the genus Psychromonas and were most closely related to Psychromonas aquatilis M1A1 T (98.1%) and Psychromonas antarctica DSM 10704 T (97.1%) for strains RZ5 T and RZ22 T , respectively. The predominant fatty acids of both strains were C 16 : 0 and summed feature 3 (C 16 : 1 ω 7 c /C 16 : 1 ω 6 c ). The major polar lipids for strain RZ5 T comprised phosphatidylethanolamine (PE) and glycolipids (GLs), while those for strain RZ22 T comprised PE, diphosphatidylglycerol and GLs. The average nt identity (ANI) and digital DNA–DNA hybridization (dDDH) values between strains RZ5 T and RZ22 T were 85.4% and 18.9%, respectively. Strain RZ5 T had ANI values of 84.3–85.5% and dDDH values of 18.3–21.3% to members of the genus Psychromonas . Strain RZ22 T had ANI values of 84.2–85.2% and dDDH values of 18.4–22.1% to members of the genus Psychrom...