Lysinibacillus capsici sp. nov., isolated from the rhizosphere of a pepper plant

Authors: BURKETT-CADENA, MARLENY - Pathway Biologic; SASTOQUE, LEONARDO - Pathway Biologic; CADENA, JOHANNA - Pathway Biologic; Dunlap, Christopher

Submitted to: Antonie Van Leeuwenhoek
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/15/2019
Publication Date: 8/1/2019
Citation: Burkett-Cadena, M., Sastoque, L., Cadena, J., Dunlap, C.A. 2019. Lysinibacillus capsici sp. nov, isolated from the rhizosphere of a pepper plant. Antonie van Leeuwenhoek. 112:1161-1167. https://doi.org/10.1007/s10482-019-01248-w.
DOI: https://doi.org/10.1007/s10482-019-01248-w

Interpretive Summary: This study characterizes the properties of a bacteria isolated from the roots of a pepper plant. The strain was identified during a screen for bacteria with plant growth promoting properties. Genome analysis revealed the bacteria represented a novel species. The basic phenotypic properties of the strain were characterized and reported. Novel bacteria such as these may possess unique and unusual biochemical properties that make them attractive candidates to explore their potential for new uses in agriculture or biotechnology. This strain is currently being evaluated for development as a commercial plant growth promoter.

Technical Abstract: An isolate of a Gram-positive, strictly aerobic, motile, rod-shaped, endospore forming bacterium was originally isolated from rhizospheric soil of a pepper plant when screening and bioprospecting for plant beneficial microorganisms. Phylogenetic analysis of the 16S rRNA gene indicated that this strain was most closely related to Lysinibacillus macroides DMS 54**T (99.6%) and Lysinibacillus xylanilyticus DSM 23493**T (99.4%). In phenotypic characterization, the novel strain was found to grow between 15-40 deg C and to tolerate up to 10% NaCl (w/v). Furthermore, the strains grew in media with pH 5 to 10 (optimal growth at pH 7.0). The predominant cellular fatty acids were iso-C15':'0 (56.6'%), anteiso-C15':'0 (14.6%), C16':1'7C alcohol (9.3%), and C16':'0 (7.1%). The cell-wall peptidoglycan contained lysine-aspartic acid, the same as congeners. A draft genome was completed and used for phylogenomic analysis and comparisons to close relatives. The DNA G+C content was 37.7 %. A phylogenomic analysis on the core genome of the new strain and 5 closest type strains of Lysinibacillus group revealed this strain formed a distinct monophyletic clade with the nearest neighbor being Lysinibacillus fusiformis. DNA-DNA relatedness studies using in silico DNA-DNA hybridizations (DDH), showed this species (<31.4%) was well below the species threshold of 70%. Based upon the consensus of phylogenetic and phenotypic analyses, we conclude that this strain represents a novel species within the genus Lysinibacillus, for which the name Lysinibacillus capsici sp. nov. is proposed, with type strain NRRL B-65515**T.