This study provides detailed insight into the impact of complex nutrient sources on the fermentation of Sporolactobacillus inulinus, a highly productive D-lactic acid producing bacterium. The composition of various yeast extracts and peptones was analyzed and compared to the cultivation results of S. inulinus. Special attention was paid to the utilization of peptides and free amino acids. It turned out that free amino acids are the limiting factor for the lactic acid production. This limitation could be prevented in a fed-batch experiment, in which the product concentration was increased to 222 g L⁻¹ by the addition of free amino acids and vitamins. Furthermore, a synthetic medium based on the analytical data of the reference yeast extract was developed to elucidate the nutritional requirements in detail.

中文翻译：

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营养要求和酵母提取物对菊粉菌中D-乳酸生产的影响

这项研究提供了对复杂营养源对菊粉孢菌发酵的影响的详细见解，菊粉孢子菌是一种高产D-乳酸生产细菌。分析了各种酵母提取物和蛋白的组成，并与菊粉链球菌的培养结果进行了比较。特别注意肽和游离氨基酸的利用。事实证明，游离氨基酸是乳酸生产的限制因素。在进料分批实验中可以避免这种局限性，在分批实验中，产物浓度增加到222 g L ^-1通过添加游离氨基酸和维生素。此外，根据参考酵母提取物的分析数据开发了一种合成培养基，以详细阐明其营养需求。