Characterization of Lysobacter capsici strain NF87–2 and its biocontrol activities against phytopathogens

Strain NF87–2 is an aerobic, non-motile and rod-shaped Gram-negative bacterium. It was isolated from the rhizosphere of green pepper. In the present study, sequence analyses of the 16S rRNA and copA genes revealed that strain NF87–2 belongs to the species Lysobacter capsici. Strain NF87–2 could produce chitinase, cellulase, protease and siderophore. The strain showed a broad spectrum of antifungal activities against phytopathogens, including Alternaria brassicae, Rhizoctonia solani, Sclerotinia sclerotiorum, Botrytis cinerea, Colletotrichum gloeosporioides and Fusarium oxysporum. The secondary metabolites secreted by strain NF87–2 could inhibit the growth of both bacteria and fungi, but the mixture of peptides and proteins extracts from a suspension of strain NF87–2 could only inhibit the mycelia growth of fungi. Our results also have shown that strain NF87–2 could control pepper damping off caused by R. solani effectively in a greenhouse setting. Our findings provide a new source for a biocontrol agent and shed light on the mechanism of the antagonistic activity of L. capsici.