Draft genome sequence of Enterococcus faecium SP15, a potential probiotic strain isolated from spring water

Comprehensive genomic analysis of hypocholesterolemic probiotic Enterococcus faecium LR13 reveals unique proteins involved in cholesterol-assimilation

Hypercholesterolemia is a major risk factor for cardiovascular diseases (CVDs). Chemotherapeutic agents for CVDs exhibit several side effects. Specific probiotics with hypocholesterolemic effects can be safe and effective alternatives to chemotherapeutics. Here, we have analyzed and compared the genome of a novel rhizospheric Enterococcus faecium LR13 cholesterol-assimilating probiotic with other probiotic/pathogenic E. faecium strains to discern genetic factors underlying probiotic efficacy and cholesterol-assimilation. Genomic analyses of E. faecium probiotic strains revealed that LR13 and WEFA23 (cholesterol-assimilating probiotics) harbored 21 unique proteins absent in non-cholesterol-assimilating probiotics. Of these, 14 proteins could directly help in cholesterol-assimilation by producing short chain fatty acids, lipid (sterol) transport and membrane stabilization, and bile salt hydrolase activity. This suggests that cholesterol-assimilation is an intrinsic, strain-specific trait exhibited by probiotics with a specific genetic constitution. Moreover, the unique proteins identified in this study can serve as biomarkers for discerning/characterizing cholesterol-assimilating probiotics as novel biotherapeutics against CVDs.

High-quality genome sequence assembly of R.A73 Enterococcus faecium isolated from freshwater fish mucus

BACKGROUND

Whole-genome sequencing using high throughput technologies has revolutionized and speeded up the scientific investigation of bacterial genetics, biochemistry, and molecular biology. Lactic acid bacteria (LABs) have been extensively used in fermentation and more recently as probiotics in food products that promote health. Genome sequencing and functional genomics investigations of LABs varieties provide rapid and important information about their diversity and their evolution, revealing a significant molecular basis. This study investigated the whole genome sequences of the Enterococcus faecium strain (HG937697), isolated from the mucus of freshwater fish in Tunisian dams. Genomic DNA was extracted using the Quick-GDNA kit and sequenced using the Illumina HiSeq2500 system. Sequences quality assessment was performed using FastQC software. The complete genome annotation was carried out with the Rapid Annotation using Subsystem Technology (RAST) web server then NCBI PGAAP.

RESULTS

The Enterococcus faecium R.A73 assembled in 28 contigs consisting of 2,935,283 bps. The genome annotation revealed 2884 genes in total including 2834 coding sequences and 50 RNAs containing 3 rRNAs (one rRNA 16 s, one rRNA 23 s and one rRNA 5 s) and 47 tRNAs. Twenty-two genes implicated in bacteriocin production are identified within the Enterococcus faecium R.A73 strain.

CONCLUSION

Data obtained provide insights to further investigate the effective strategy for testing this Enterococcus faecium R.A73 strain in the industrial manufacturing process. Studying their metabolism with bioinformatics tools represents the future challenge and contribution to improving the utilization of the multi-purpose bacteria in food.