Selection of Bacillus spp. as fermentation cultures for production of plant-based cheese analogues

Bacillus species are beneficial fermentation microbes that exhibit useful technological traits including the expression of extracellular amylolytic and proteolytic enzymes and antimicrobial lipopeptides. In this study, strains of Bacillus spp. were screened through genome analysis and the effect of fermentation of plant-based cheese analogues with the acidification cultures Lactococcus lactis, Lactococcus cremoris and Leuconostoc mesenteroides, and the adjunct culture Lentilactobacillus. buchneri plus Bacillus spp. was investigated. Based on genome analyses of 9 strains of Bacillus spp., B. velezensis FUA2155, B. amyloliquefaciens FUA2153, and B. subtilis FUA2114 that harbor genes encoding for amylases and proteases and lipopeptide synthases were selected for fermentation of plant cheese. Bacillus strains exhibited metabolic activity during bean germination but were inactive after acidification of the cheese matrix. The strains prolonged the mould-free storage time of plant-based cheese analogues and enhanced proteolysis. Of the three strains, only B. velezensis FUA2155 contributed to accumulation of taste-active glutamate. Lt. buchneri accelerated the inactivation of Ln. mesenteroides and enhanced the prevention against fungal contaminants in plant-based cheese analogues with bacilli at the ripening condition rH of 0.78. Taken together, this study provides evidence that the use of proteolytic strains of Bacillus in combination with the acidification cultures Lc. lactis and Lc. cremoris associated with Ln. mesenteroides and adjunct culture Lt. buchneri improved the quality of fermented plant-based cheese analogues.