*3.1. Isolation of the Strains Belonging to the Genus Cobetia*

Bacterial strains were isolated from the different marine environments, including coastal waters, sediments, seaweeds and animals, using the standard dilution-plating method. Strains KMM 6284 and KMM 6731 were directly isolated from the red alga *Ahnfeltia tobuchiensis* collected near Island Paramushir, Kuril Isles, the Sea of Okhotsk, and the Pacific Ocean. Strains KMM 6816, 6817 and 6818 were isolated from the same alga after its long-term continuous cultivation in the natural seawater for 6 months. Strain KMM 7000 was recovered from the sponge *Esperiopsis digitata,* collected near Island Sakhalin, Piltun

Bay, the Sea of Okhotsk, from depth of 107 m by plating on medium A containing (L<sup>−</sup>1): 2 g Bacto peptone (Difco), 2 g Bacto yeast extract (Difco), 1 g casein hydrolysate, 0.2 g KH2PO4 and 0.1 g ferric ammonium citrate prepared with 50% (*v*/*v*) natural sea water and 50% (*v*/*v*) distilled water. For strains isolation, 0.1 mL of tissue homogenate was transferred onto plates of marine agar 2216 (MA; Difco) (strains KMM 6284, 6731, 6816, 6817, and 6818) or medium A or medium B. After primary isolation and purification, the strains were cultivated at 28 ◦C on the same medium and stored at –80 ◦C in marine broth (Difco) supplemented with 20% (*v*/*v*) glycerol. Strains KMM 7516, 7505, 7515 and 7508, and 7514 and 7005 were isolated from coastal seawater and sediment samples, respectively, collected from Vostok Bay, the Sea of Japan, by plating on medium B, containing: 1 g (NH4)2SO4, 0.2 g MgSO4 7H2O, 1 g K2HPO4, 1 g KH2PO4, 0.02 g CaCl2, 0.05 g FeCl3, and 20 g NaCl in 1000 mL distilled water, with the addition of 1 mL per liter of sterile crude oil to the prepared medium. Strain *Cobetia* sp. KMM 296, previously identified as *Deleya marina* by Ivanova et al. [35], was received from the Collection of Marine Microorganisms (KMM, Russia). The type strains of the recognized species *Cobetia amphilecti* KMM 1561<sup>T</sup> (NRIC 0815T), *Cobetia litoralis* KMM 3880<sup>T</sup> (NRIC 0814T), *Cobetia pacifica* KMM 3879<sup>T</sup> (NRIC 0813T), and *Cobetia marina* LMG 2217<sup>T</sup> were used as reference strains and kindly provided to us by the NODAI Culture Collection Center, (University of Agriculture, Tokyo, Japan) and from the BCCM/LMG Bacteria Collection (Universiteit Gent, Gent, Belgium), respectively [7]. The reference type strain *C. crustatorum* JCM 15644T was kindly provided by the Japan Collection of Microorganisms (RIKEN BioResource Centre (BRC), Tsukuba, Japan).
