Mahdinia Ehsan, Demirci Ali, Berenjian Aydin
Department of Agricultural and Biological Engineering, The Pennsylvania State University, University Park, PA, 16802, United States.
Faculty of Science and Engineering, The University of Waikato, Hamilton, 3240, New Zealand.
Curr Pharm Biotechnol. 2018;19(11):917-924. doi: 10.2174/1389201020666181126120401.
Benefits of vitamin K have been reported by many studies recently, due to its ability to reduce the risk of cardiovascular diseases and its potential benefits against osteoporosis. Specifically, menaquinone-7 (MK-7), being the most potent form of vitamin K, has definitely received most of the attention. Currently, solid or static liquid fermentation strategies are utilized for industrial production of MK-7 by Bacillus strains. However, these strategies face fundamental operational and scale-up issues as well as intense pellicle and biofilm formations which is problematic in static liquid fermentation, due to heat and mass transfer inefficiencies they create.
The purpose of this study was to demonstrate that biofilm reactors will overcome the issues associated with suspended cell reactors when using Bacillus strains to produce MK-7. The expectation is that the use of biofilm reactors will result in a significant increase in the production of MK-7.
Vitamin K production by Bacillus subtilis natto when grown in a biofilm reactor was evaluated at various concentrations of the three major nutrients, glucose, yeast extract and casein. The data was analyzed using response surface methodology (RSM).
The maximum concentration of MK-7 in the biofilm reactors was 20.5±0.5 mg/L, which was a 344 % increase when compared to the amount produced in suspended-cell reactors containing the same optimum media composition.
These results demonstrate the potential of utilizing biofilm reactors for MK-7 production on an industrial scale.
近期许多研究报道了维生素K的益处，这归因于其降低心血管疾病风险的能力以及对骨质疏松症的潜在益处。具体而言，甲萘醌-7（MK-7）作为维生素K最有效的形式，无疑受到了最多关注。目前，固态或静态液体发酵策略被用于芽孢杆菌菌株工业生产MK-7。然而，这些策略面临着基本的操作和放大问题，以及在静态液体发酵中严重的菌膜和生物膜形成问题，这是由于它们造成的传热和传质效率低下所致。
本研究的目的是证明在使用芽孢杆菌菌株生产MK-7时，生物膜反应器将克服与悬浮细胞反应器相关的问题。预期使用生物膜反应器将导致MK-7产量显著增加。
在生物膜反应器中培养纳豆芽孢杆菌时，评估了三种主要营养物质葡萄糖、酵母提取物和酪蛋白在不同浓度下的维生素K产量。使用响应面法（RSM）分析数据。
生物膜反应器中MK-7的最大浓度为20.5±0.5 mg/L，与含有相同最佳培养基成分的悬浮细胞反应器中产生的量相比，增加了344%。
这些结果证明了在工业规模上利用生物膜反应器生产MK-7的潜力。
