Laureys David, Aerts Maarten, Vandamme Peter, De Vuyst Luc
Research Group of Industrial Microbiology and Food Biotechnology, Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium.
Laboratory of Microbiology, Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, Ghent, Belgium.
Front Microbiol. 2019 Dec 13;10:2876. doi: 10.3389/fmicb.2019.02876. eCollection 2019.
Eight water kefir fermentation series differing in buffer capacity and calcium concentration of the water used for fermentation were studied during eight backslopping steps. High buffer capacities resulted in high pH values and high calcium concentrations resulted in low pH values at the end of each backslopping step. When the water buffer capacity and/or calcium concentration were below certain minima, the water kefir grain growth decreased gradually over multiple backsloppings. High water buffer capacities resulted in high concentrations of residual total carbohydrate concentrations and low metabolite concentrations. Further, high water buffer capacities resulted in high ratios of lactic acid bacteria to yeasts, which was reflected in high molar ratios of the concentrations of lactic acid to ethanol and acetic acid to ethanol. The most prevalent microorganisms of the water kefir grain inoculum and grains of all fermentation series at the end of the eighth backslopping step were , , , , , and . These microbial communities were influenced by the water buffer capacity and had an impact on the substrate consumption and metabolite production during water kefir fermentation.
在八个回添步骤中，研究了八个水开菲尔发酵系列，这些系列在用于发酵的水的缓冲能力和钙浓度方面存在差异。在每个回添步骤结束时，高缓冲能力导致高pH值，高钙浓度导致低pH值。当水的缓冲能力和/或钙浓度低于某些最小值时，水开菲尔粒的生长在多个回添过程中逐渐减少。高水缓冲能力导致残留总碳水化合物浓度高和代谢物浓度低。此外，高水缓冲能力导致乳酸菌与酵母的比例高，这反映在乳酸与乙醇以及乙酸与乙醇浓度的高摩尔比上。在第八个回添步骤结束时，水开菲尔粒接种物和所有发酵系列的粒中最普遍的微生物是 、 、 、 、 和 。这些微生物群落受水缓冲能力的影响，并对水开菲尔发酵过程中的底物消耗和代谢物产生有影响。
