基于ARTP技术选育维生素K2优势菌株及发酵培养基优化

本研究目的在于获得维生素K₂优势突变株，并利用响应面设计优化发酵培养基进一步提高其产量。采取常压室温等离子体诱变技术结合结构类似物抗性初筛、24孔板发酵复筛，对纳豆芽孢杆菌进行诱变选育，并应用Box-Behnken设计对发酵培养基进行优化。通过ARTP诱变选育得到一株维生素K₂优势突变株，维生素K2产量较初始菌株提高了3.23倍。Box-Behnken实验优化后，最佳值为K₂HPO₄（0.69 g/L），甘油（66.01 g/L）和酵母粉（25.12 g/L），发酵后维生素K₂产量较优化前提高了56.7%。通过ARPT技术诱变选育出一株维生素K2优势突变株，采用响应面法优化发酵培养基。实验结果表明，突变株具有潜在的生产应用价值，建立的育种方法也可为其他工业微生物的选育提供有益的参考，对提高人们的健康水平具有十分重要的意义。

Screening of High-Yield Vitamin K2 Strain Based on ARTP Technology and Optimization of Fermentation Medium

This study aimed to obtain the vitamin K₂ dominant mutant and to further improve its yield via the fermentation medium optimization using response surface design. The mutagenesis breeding of bacillus natto was carried out through room temperature plasma (ARTP) in combination with the structural analog resistance screening under atmospheric pressure, subsequently rescreened by 24 bore plates fermentation. The fermentation medium was then optimized by Box-Behnken design. A dominant mutant strain of vitamin K₂ was obtained by ARTP mutagenesis with a yield of 3.23 times higher than that of the original strain. The optimal values based on Box-Behnken design were 0.69 g/L of K₂HPO₄, 66.01 g/L of glycerol and 25.12 g/L of yeast powder, with an increase of 56.7% of vitamin K₂ yield. A dominant mutant strain of vitamin K₂ was achieved by ARTP mutagenesis and the fermentation medium was effectively optimized by response surface methodology. The experimental results showed that the mutant strain has potential value in production and application, establishing the breeding method with a beneficial reference for the selection and breeding of other industrial microorganisms, which is of great significance to improve human health.