Systems Biology, R&D Discovery, Chr. Hansen A/S, Hørsholm, Denmark.
Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
Appl Environ Microbiol. 2023 Mar 29;89(3):e0008223. doi: 10.1128/aem.00082-23. Epub 2023 Feb 21.
Some probiotic bifidobacteria are highly robust and shelf-stable, whereas others are difficult to produce, due to their sensitivity to stressors. This limits their potential use as probiotics. Here, we investigate the molecular mechanisms underlying the variability in stress physiologies of Bifidobacterium animalis subsp. BB-12 and Bifidobacterium longum subsp. BB-46, by applying a combination of classical physiological characterization and transcriptome profiling. The growth behavior, metabolite production, and global gene expression profiles differed considerably between the strains. BB-12 consistently showed higher expression levels of multiple stress-associated genes, compared to BB-46. This difference, besides higher cell surface hydrophobicity and a lower ratio of unsaturated to saturated fatty acids in the cell membrane of BB-12, should contribute to its higher robustness and stability. In BB-46, the expression of genes related to DNA repair and fatty acid biosynthesis was higher in the stationary than in the exponential phase, which was associated with enhanced stability of BB-46 cells harvested in the stationary phase. The results presented herein highlight important genomic and physiological features contributing to the stability and robustness of the studied strains. Probiotics are industrially and clinically important microorganisms. To exert their health-promoting effects, probiotic microorganisms must be administered at high counts, while maintaining their viability at the time of consumption. In addition, intestinal survival and bioactivity are important criteria for probiotics. Although bifidobacteria are among the most well-documented probiotics, the industrial-scale production and commercialization of some strains is challenged by their high sensitivity to environmental stressors encountered during manufacturing and storage. Through a comprehensive comparison of the metabolic and physiological characteristics of 2 strains, we identify key biological markers that can serve as indicators for robustness and stability in bifidobacteria.
一些益生菌双歧杆菌具有很强的稳定性和耐储存性，而其他双歧杆菌则由于对胁迫因子敏感而难以生产。这限制了它们作为益生菌的潜在用途。在这里，我们通过应用经典生理特性研究和转录组谱分析相结合的方法，研究了双歧杆菌亚种。动物 BB-12 和长双歧杆菌亚种。BB-46 应激生理变异性的分子机制。菌株之间的生长行为、代谢产物产生和全基因组表达谱有很大差异。与 BB-46 相比，BB-12 始终表现出多个与应激相关基因的更高表达水平。这种差异，除了 BB-12 细胞表面疏水性更高和细胞膜中不饱和脂肪酸与饱和脂肪酸的比例更低外，应该有助于其更高的稳定性和稳定性。在 BB-46 中，与 DNA 修复和脂肪酸生物合成相关的基因在静止期的表达高于指数期，这与静止期收获的 BB-46 细胞稳定性增强有关。本文介绍的结果强调了有助于研究菌株稳定性和鲁棒性的重要基因组和生理特征。益生菌是工业和临床应用中非常重要的微生物。为了发挥其促进健康的作用，益生菌微生物必须以高计数给药，同时在食用时保持其活力。此外，肠道存活和生物活性是益生菌的重要标准。尽管双歧杆菌是最有文献记载的益生菌之一，但一些菌株的工业化生产和商业化受到其在制造和储存过程中对环境胁迫因子高度敏感的挑战。通过对 2 株菌代谢和生理特性的全面比较，我们确定了关键的生物学标志物，可作为双歧杆菌健壮性和稳定性的指标。
