A Gram-stain-negative, motile with flagellum, ovoid- or rod-shaped, aerobic bacterium, was isolated from the phycosphere of the microalga Chlorellavulgaris and designated as strain LMIT002T. The bacterium formed white, circular and smooth colonies on marine agar 2216 after 48 h incubation at 25 °C. On the basis of 16S rRNA gene sequence analysis, strain LMIT002T was found to be affiliated with the family Rhodobacteraceae of the order Rhodobacterales, and formed a distinct group. The 16S rRNA gene sequence similarities between strain LMIT002T and type strains in the family including Poseidonocella pacifica DSM 29316T, Roseobacter litoralis and Rhodovulum sulfidophilum were 95.1, 95.0 and 95.0 %, respectively. Strain LMIT002Tgrew optimally at 25 °C, pH 6.0 and in the presence of 2.0 % (w/v) NaCl. The genomic DNA G+C content was 67.0 mol% (the thermal denaturation method) or 66.9 % (genome sequencing). The sole respiratory quinone was ubiquinone-8, while the major fatty acids were summed feature 8 (C18 : 1 ω7с/C18 : 1 ω6с). The draft genome of strain LMIT002T was sequenced and annotated, with the results showing that it had a total size of 4 607 780 bp and comprised 4557 genes. Functional genes encoding the production of vitamin B12, indole-3-acetic acid and transform dimethylsulphoniopropionate were detected. Given its distinct genomic, morphological and physiological differences from previously described type strains, strain LMIT002T is proposed as a representative of a novel genus of the family Rhodobacteraceae, with the name Phycocomes zhengii gen. nov., sp. nov. The type strain is LMIT002T (=KCTC 62390T=CICC 24357T).