Comparative genomic analysis and fermentation performance of Lactiplantibacillus plantarum strains in blueberry (Vaccinium spp.) juice

Abstract

As a versatile lactic acid bacterium, Lactiplantibacillus plantarum is a prominent probiotic, widely recognized for its beneficial roles in fermented juice.This study investigated the fermentation performance in blueberry (Vaccinium spp.) juice of three L. plantarum strains: two novel isolates from our laboratory (B4 and SS6) and one commercial strain LP39. All strains were suitable for growth in blueberry juice, with activity influenced by inoculation method. This research's originality stems from its innovative application of whole-genome sequencing and comparative genomic analysis to elucidate the specific genetic diversity, metabolic capabilities, and crucial safety aspects of these L. plantarum strains for blueberry juice fermentation. Genome analysis revealed no virulence genes; strains showed natural resistance to vancomycin and streptomycin and no hemolytic activity. A simple, easy-to-implement, highly reproducible, and linear method based on PMA-CELL-qPCR was developed for the real-time quantitative monitoring of the aforementioned specific strains at the strain level in blueberry juice. Further research found that B4 and SS6 exhibited better growth abilities in blueberry juice than LP39, due to their additional acid stress tolerance genes. Furthermore, inoculation with L. plantarum improved the antioxidant capacity of blueberry juice, with mixed inoculation of B4 and LP39 significantly increasing total anthocyanin content, while B4 with SS6 increased total phenol content. A total of 86 aroma compounds were detected by using HS-SPME-GC-MS and inoculation with B4 significantly increased mono-terpenoids. The conduct of this study provides scientific evidence and technical support for the selection and application of strains suitable for the fermentation of blueberry functional beverages.