Characterization of a Novel Endophytic Actinomycete, sp. nov., and Its Biocontrol Potential Against on Tomato.

Bacterial wilt of tomato is a destructive disease caused by throughout the world. An endophytic actinomycete with antagonistic activity, designated strain LD120, was isolated from moss ( (Ludw) Fuernr). The biocontrol test demonstrated that co-inoculation by the isolate and the pathogen gave the greatest biocontrol efficiency of 63.6%. Strain LD120 had morphological characteristics and chemotaxonomic properties identical to those of members of the genus . The diamino acid present in the cell wall was LL-diaminopimelic acid. Arabinose, glucose, rhamnose, and ribose occured in whole cell hydrolysates. The menaquinones detected were MK-9(H), MK-9(H), MK-9(H), and MK-9(H). The polar lipid profile was found to contain diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylinositol. The major cellular fatty acids were found to be iso-C, iso-C, anteiso-C, and C ω7c. The DNA G+C content of the draft genome sequence, consisting of 7.6 Mbp, was 73.1%. Analysis of the 16S rRNA gene sequence showed that strain LD120 belongs to the genus , with the highest sequence similarity to NRRL B-2655 (98.97%), but phylogenetically clustered with NRRL B-3590 (98.62%). Multilocus sequence analysis based on five other house-keeping genes (, , , , and and the low level of DNA-DNA relatedness, as well as phenotypic differences, allowed strain LD120 to be differentiated from its closely related strains. Therefore, the strain was concluded to represent a novel species of the genus , for which the name sp. nov. was proposed. The type strain was LD120 (=CCTCC AA 2018049 = DSM 110638).