摘要
为进一步提高纳豆芽胞杆菌合成维生素K;的能力,根据前期不同转速对维生素K;产量影响的结果,在250 mL摇瓶中考察转速0(产量最大)和200 r/min(产量其次)对菌体生长和产物生成的影响。通过分析不同条件下发酵进程曲线与发酵动力学参数,并对不同时间点的发酵液进行稀释涂布和扫描电镜观察菌体形态变化,提出两阶段转速调控策略,并对影响此调控策略的条件(温度、转速、pH和时间)进行正交优化。0 r/min、108 h产量最高,发酵后期菌体形态多为褶皱,200 r/min菌体数量高于0 r/min,菌体在发酵后期破碎较多,少数表面平整;优化后在40℃、p H 6.5、0~36 h控制转速220 r/min,36~132 h转速为0 r/min,维生素K;的产量为(35.60±0.13) mg/L,比优化前(0、200 r/min)分别提高了1.67倍和9.674倍。分阶段调控转速可以有效提高纳豆芽胞杆菌合成维生素K;的能力,对维生素K;的大规模生产具有重要的指导意义和参考价值。
To further improve the ability of Bacillus subtilis natto to synthesize vitamin K;, the effect of rotational speed(0、200 r/min) on cell growth and product formation was investigated in 250 m L shake flasks. A two-stage rotational speed control strategy was proposed by analyzing the fermentation process curves and kinetic parameters under different conditions, as well as by observing the morphological changes between the bacteria at different time points after diluting and coating the fermentation broth with scanning electron microscopy. The conditions(temperature,speed, pH and time) affecting the control strategy were optimized by orthogonal design. When the rotate speed was maintained at 0 r/min, the highest yield of vitam in K;was obtained at 108 h and the morphology of bacteria was mostly folded at the later stage of fermentation. When the rotate speed was maintained at 200 r/min, the biomass was higher than that at 0 r/min. The bacteria were broken at the later stage of fermentation, and a few of them had a smooth surface. After optimization, the yield of vitamin K;reached(35.6 ±0.13) mg/L at 40 ℃ and pH 6.5 when the rotate speed was maintained at 200 r/min from 0 h to 36 h, and maintained at 0 r/min from 36 h to 132 h, which was1.67 times and 9.674 times higher than that before optimization(0、200 r/min), respectively. The stage-by-stage control of rotational speed could effectively improve the ability of Bacillus subtilis natto to synthesize vitamin K;, which is of great guiding significance and reference value for the large-scale production of vitamin K;.
作者
冯静静
吴静
李伟
周梦洁
胡汶松
汪剑
薛正莲
王洲
刘艳
FENG Jingjing;WU Jing;LI Wei;ZHOU Mengjie;HU Wensong;WANG Jian;XUE Zhenglian;WANG Zhou;LIU Yan(College of Biological and Chemical Engineering,Anhui Polytechnic University,Wuhu 241000,China;Anhui Engineering Technology Research Center of Microbial Fermentation,Wuhu 241000,China)
出处
《食品与生物技术学报》
CAS
CSCD
北大核心
2022年第2期37-45,共9页
Journal of Food Science and Biotechnology
基金
国家自然科学基金项目(31871781,31772081)
安徽高校自然科学研究重点项目(KJ2018A0106)
芜湖市科技计划重点项目(2020yf62)
国家级大学生创新创业项目(201910363042,201810363046)
安徽省大学生创新创业计划项目(201710363178)。
关键词
纳豆芽胞杆菌
维生素K
扫描电镜
发酵动力学
正交优化
Bacillus subtilis natto
vitamin K2
scanning electron microscopy
fermentation kinetics
orthogonal optimization
作者简介
通信作者:刘艳(1981—),女,博士,教授,硕士研究生导师,主要从事资源生物技术方面的研究。E-mail:liuyan@ahpu.edu.cn。
