A novel bacterial strain, designated as CF21(T), was isolated from the air of Ailuropoda melanoleuca enclosures in China. Cells were gram-negative, aerobic, non-motile, and rod shaped. Strain CF21(T) grew at 10-40 A degrees C (optimum 28-30 A degrees C) and pH 6.0-9.0 (optimum pH 7.0-8.0) and in the presence of NaCl concentrations ranging from 0.0 % (w/v) to 2.0 % (optimum 0.0-1.0 %). 16SrRNA gene sequence analysis indicated that strain CF21(T) belonged to genus Lysobacter within class Gammaproteobacteria and was most closely related to Luteimonas dalianensi OB44-3(T) (95.8 % similarity), Lysobacter ruishenii CTN-1(T) (95.1 %), Lysobacter spongiicola KMM329(T) (94.8 %), and Lysobacter daejeonensis GH1-9(T) (94.6 %). The genomic G+C DNA content was 68.72 mol%. Major cellular fatty acids of CF21(T) were iso-C-16:0 (30.22 %), iso-C-15:0 (25.70 %), and the sum of 10-methyl C-16:0 and/or iso-C-17:1 omega 9c (21.94 %). The prominent isoprenoid quinone was ubiquinone 8 (Q-8). Primary polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and an unknown phospholipid. DNA sequence relatedness between strain CF21(T) and L. ruishenii CTN-1(T) was 56 %, which was clearly below the 70 % threshold for prokaryotic species delineation. These analyses indicated that CF21(T) is a novel member of genus Lysobacter, for which the name Lysobacter chengduensis sp. nov. is proposed. The type strain is CF21(T) (=CGMCC1.15145(T) = DSM 100306(T)).