Abstract
It is important for probiotics that are currently utilized in the dairy industry to have clear genetic backgrounds. In this study, the genetic characteristics of Lactobacillus kefiranofaciens ZW3 were studied by undertaking a comparative genomics study, and key genes for adaptation to different environments were investigated and validated in vitro. Evidence for horizontal gene transfer resulting in strong self-defense mechanisms was detected in the ZW3 genome. We identified a series of genes relevant for dairy environments and the intestinal tract, particularly for extracellular polysaccharide (EPS) production. Reverse transcription-qPCR (RT-qPCR) revealed significant increases in the relative expression of pgm, ugp, and uge during the mid-logarithmic phase, whereas the expression of pgi was higher at the beginning of the stationary phase. The enzymes encoded by these four genes concertedly regulated carbon flux, which in turn modulated the production of EPS precursors. Moreover, ZW3 tolerated pH 3.5 and 3% bile salt and retained cell surface hydrophobicity and auto-aggregation. In conclusion, we explored the potential of ZW3 for utilization in both the dairy industry and in probiotic applications. Additionally, we elucidated the regulation of the relevant genes involved in EPS production.
Highlights
The LAB genome that were related to adaptation to the intestinal tract or a milk environment may facilitate the determination of whether a strain has the potential for probiotic or dairy applications in industry
ZW3 was originally isolated from the traditional functional fermentation product kefir and produces high levels of extracellular polysaccharide (EPS)[15,16]
Since new whole-genome sequences have been uploaded to the database, and more information was available for exploration in this study; we carried out the re-annotation
Summary
Received: 31 March 2017 Accepted: 11 September 2017 Published: xx xx xxxx of Lactobacillus. spp reveal adaptations to dairy and gut environments. The genetic characteristics of Lactobacillus kefiranofaciens ZW3 were studied by undertaking a comparative genomics study, and key genes for adaptation to different environments were investigated and validated in vitro. The LAB genome that were related to adaptation to the intestinal tract or a milk environment may facilitate the determination of whether a strain has the potential for probiotic or dairy applications in industry. Lb. kefiranofaciens contributes to kefiran formation and plays a role in a wide range of probiotic functions, such as immunomodulation[12], anti-allergic potential[13], and modulation of the gut microbiota[14] Studies on this species at the genomic level are limited; for example, one investigation involved screening the biotechnology potential of 213 strains, but less information was provided for this species[7]. Relevant genes for its survival in dairy and intestinal environments were analyzed and verified
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
