The safety and technological properties of Bacillus velezensis DMB06 used as a starter candidate were evaluated by genome analysis

Abstract

Screening of good starter candidates for fermented food is continuously required. Accordingly, safety and functional evaluation were performed for 171 Bacillus velezensis strains isolated from fermented soybeans. All the strains were susceptible to ampicillin, chloramphenicol, clindamycin, erythromycin, gentamicin, and vancomycin; however, one and 135 strains showed resistance to streptomycin and tetracycline, respectively. No toxin-related genes were identified in any of the strains. All the strains grew on medium supplemented with 10% NaCl, and some strains grew weakly at ≥15% (w/w) NaCl. All the strains bar one showed protease activity in 6% NaCl; 32.7% of the strains showed lipase activity. On the basis of these assessments, B. velezensis strain DMB06 was selected as the best starter candidate because of its high protease and lipase activities. Its whole genome was sequenced, providing genetic information to support its phenotypic salt tolerance, protease and lipase activities, antibiotic susceptibility, and the absence of toxin and aminoglycoside production. Our results suggest that B. velezensis DMB06 can be safely applied as a starter candidate in the food industry.