Biocontrol Effect of Bacillus velezensis D7-8 on Potato Common Scab and Its Complete Genome Sequence Analysis

Potato common scab, caused by <i>Streptomyces</i> species, is a widespread soil-borne disease that poses a significant threat to potato cultivation globally. In this study, a <i>Bacillus velezensis</i> D7-8 strain was isolated from a potato. This endophytic bacterium exhibited broad-spectrum antifungal activity, and pot trials demonstrated that the D7-8 strain effectively controlled potato common scab with an efficacy of 42.07%. The complete genome sequence of the D7-8 strain was sequenced and subsequently identified as <i>B. velezensis</i> through multiple bioinformatic methods, primarily through structural variation analysis of whole-genome sequences. The machine learning method predicted that the expression profiles of colinear genes among closely related <i>Bacillus</i> species were highly consistent. Metabolite analysis of crude extracts using ultra-high-performance liquid chromatography coupled with quadrupole-Orbitrap high-resolution mass spectrometry (UPLC-Q-Exactive HRMS) revealed that D7-8 produces bioactive compounds, including surfactin and fengycin, both known for their antimicrobial properties. This study elucidates the antagonistic effect of <i>B. velezensis</i> D7-8 against <i>Streptomyces acidiscabies</i> and provides a valuable reference for future research on accurate microbial identification.