Adamberg Kaarel, Raba Grete, Adamberg Signe
Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia.
Center of Food and Fermentation Technologies, Tallinn, Estonia.
Front Bioeng Biotechnol. 2020 Feb 7;8:24. doi: 10.3389/fbioe.2020.00024. eCollection 2020.
Human colon microbiota, composed of hundreds of different species, is closely associated with several health conditions. Controlled cultivation and up-to-date analytical methods make possible the systematic evaluation of the underlying mechanisms of complex interactions between the members of microbial consortia. Information on reproducing fecal microbial consortia can be used for various clinical and biotechnological applications. In this study, chemostat and changestat cultures were used to elucidate the effects of the physiologically relevant range of dilution rates on the growth and metabolism of adult fecal microbiota. The dilution rate was kept either at = 0.05 or = 0.2 1/h in chemostat cultures, while gradually changing from 0.05 to 0.2 1/h in the A-stat and from 0.2 to 0.05 1/h in the De-stat. Apple pectin as a substrate was used in the chemostat experiments and apple pectin or birch xylan in the changestat experiments, in the presence of porcine mucin in all cases. The analyses were comprised of HPLC for organic acids, UPLC for amino acids, GC for gas composition, 16S-rDNA sequencing for microbial composition, and growth parameter calculations. It was shown that the abundance of most bacterial taxa was determined by the dilution rate on both substrates. , , and were prevalent within the whole range of dilution rates. and Ruminococcaceae UCG-013 were significantly enriched at = 0.05 1/h, while , Lachnospiraceae unclassified and clearly preferred = 0.2 1/h. In the chemostat cultures, the production of organic acids and gases from pectin was related to the dilution rate. The ratio of acetate, propionate and butyrate was 5:2:1 ( = 0.05 1/h) and 14:2:1 ( = 0.2 1/h). It was shown that the growth rate-related characteristics of the fecal microbiota were concise in both directions between = 0.05 and 0.2 1/h. Reproducible adaptation of the fecal microbiota was shown in the continuous culture with a changing dilution rate: changestat. Consortia cultivation is a promising approach for research purposes and several biotechnological applications, including the production of multi-strain probiotics and fecal transplantation mixtures.
由数百种不同物种组成的人类结肠微生物群与多种健康状况密切相关。可控培养和最新的分析方法使得系统评估微生物群落成员之间复杂相互作用的潜在机制成为可能。关于重现粪便微生物群落的信息可用于各种临床和生物技术应用。在本研究中，使用恒化器和变化状态培养来阐明生理相关稀释率范围对成人粪便微生物群生长和代谢的影响。在恒化器培养中，稀释率保持在D = 0.05或D = 0.2 1/h，而在A状态下从0.05逐渐变化到0.2 1/h，在De状态下从0.2变化到0.05 1/h。在恒化器实验中使用苹果果胶作为底物，在变化状态实验中使用苹果果胶或桦木木聚糖，所有情况下均存在猪粘蛋白。分析包括用于有机酸的HPLC、用于氨基酸的UPLC、用于气体成分的GC、用于微生物组成的16S-rDNA测序以及生长参数计算。结果表明，两种底物上大多数细菌类群的丰度由稀释率决定。在整个稀释率范围内，Prevotella、Bacteroides和Faecalibacterium普遍存在。Ruminococcus和Ruminococcaceae UCG-013在D = 0.05 1/h时显著富集，而Bifidobacterium、未分类的Lachnospiraceae和Roseburia明显偏好D = 0.2 1/h。在恒化器培养中，果胶产生有机酸和气体与稀释率有关。乙酸、丙酸和丁酸的比例在D = 0.05 1/h时为5:2:1，在D = 0.2 1/h时为14:2:1。结果表明，粪便微生物群的生长速率相关特征在D = 0.05和0.2 1/h之间的两个方向上都很简洁。在稀释率不断变化的连续培养中，即变化状态培养中，显示出粪便微生物群的可重现适应性。群落培养是一种有前途的研究方法和多种生物技术应用，包括生产多菌株益生菌和粪便移植混合物。
