Abstract

Nitrogen source has a vital role for the efficient growth of lactobacilli. The effects of cheese whey, corn steep liquor, and wheat germ extract on the growth of L. plantarum strain RPR42 in cane molasses-based media was evaluated using various approaches of design of experiments. Our results showed that such protein-rich agricultural by-products significantly increase the biomass production of the strain RPR42 in cane molasses-based media. The most affecting nitrogenous material was cheese whey followed by CSL and the minor effect was reported for wheat germ extract as revealed in factorial and Box–Behnken design experiments. The replacement of costly beef extract and yeast extract with a defined mixtures of the above nitrogenous agricultural by-products in cane molasses-based medium led to production of up to 12.64 g/L/24 h of dry biomass of strain RPR42. A detectable cell density of strain RPR42 (~ 9.81 × 10⁹ CFU/mL 24 h) which was observed in such an economic medium showed that the large-scale production of the strain RPR42 tend to be feasible at significantly low costs.

中文翻译：

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在基于甘蔗糖蜜的培养基中筛选功能性益生菌植物乳杆菌RPR42生物量过量生产的有效氮源

摘要

氮源对于乳酸菌的有效生长至关重要。干酪乳清，玉米浆和小麦胚芽提取物对植物乳杆菌生长的影响甘蔗糖蜜基培养基中的RPR42菌株使用实验设计的各种方法进行了评估。我们的结果表明，这种富含蛋白质的农业副产品在基于甘蔗糖蜜的培养基中显着提高了RPR42菌株的生物量产量。影响最大的含氮物质是干酪乳清，其次是CSL，据析因和Box-Behnken设计实验显示，对小麦胚芽提取物的影响较小。在甘蔗糖蜜基培养基中，用上述含氮农业副产品的确定混合物代替昂贵的牛肉提取物和酵母提取物，导致产生最高12.64 g / L / 24 h的RPR42菌株干生物量。RPR42菌株的可检测细胞密度（〜9.81×10 ⁹ 在这种经济介质中观察到的CFU / mL 24 h）表明，以显着较低的成本大规模生产RPR42菌株是可行的。