Zhang Hui, Zhang Wenwen, Zhang Wen, Yin Minghan, Jiao Lefei, Ming Tinghong, Jia Xiwen, Gouife Moussa, Xu Jiajie, Kong Fei
Microbial Development and Metabolic Engineering Laboratory, School of Marine Science, Ningbo University, Ningbo 315211, China.
Key Laboratory of Aquacultural Biotechnology, Ministry of Education, Ningbo University, Ningbo 315211, China.
Foods. 2025 Aug 30;14(17):3066. doi: 10.3390/foods14173066.
Microbial proteins offer a sustainable alternative for animal nutrition. NDS, a bacterium isolated from seawater, was previously identified as a promising candidate due to its high protein content. This study aimed to enhance its single cell protein production through systemic fermentation optimization. Single-factor optimization in shake flask determined the optimal conditions to be: a salinity of 20‱ NaCl, a temperature of 32 °C, and an initial pH of 7.3, and a medium composed of 1% (/) corn flour, 1% peptone, 0.3% beef extract, and 0.2% KCl. Scaling up to a 10 L bioreactor demonstrated that a two-stage agitation strategy (150 rpm for the first 20 h followed by 180 rpm for the remaining 12 h) enhanced single cell protein yield. Furthermore, allowing the pH to fluctuate freely was more beneficial for protein production than maintaining a constant pH of 7.3 ± 0.02. Under these optimized conditions, the biomass composition (wet weight) was determined to be 2.3767 ± 0.0205% crude ash, 15.6013 ± 0.0082% crude protein, 0.1023 ± 0.0026% crude lipid, and 2.6997 ± 0.0021% carbohydrates. Amino acid analysis revealed a rich profile, with lysine and glutamic acid being the predominant essential and non-essential amino acids, respectively. Fatty acids analysis indicated that C14:1n5 was the most dominant. These findings underscore the potential of NDS as a high-quality dietary protein supplement and provide a solid foundation for its industrial-scale production.
微生物蛋白为动物营养提供了一种可持续的替代方案。NDS是一种从海水中分离出的细菌，因其高蛋白含量，先前被确定为一个有前景的候选对象。本研究旨在通过系统的发酵优化提高其单细胞蛋白产量。摇瓶中的单因素优化确定最佳条件为：氯化钠盐度20‰、温度32℃、初始pH值7.3，以及由1%（/）玉米粉、1%蛋白胨、0.3%牛肉浸膏和0.2%氯化钾组成的培养基。放大至10 L生物反应器表明，两阶段搅拌策略（前20小时150 rpm，其余12小时180 rpm）提高了单细胞蛋白产量。此外，允许pH值自由波动比维持恒定pH值7.3±0.02更有利于蛋白质生产。在这些优化条件下，生物质组成（湿重）确定为粗灰分2.3767±0.0205%、粗蛋白15.6013±0.0082%、粗脂肪0.1023±0.0026%和碳水化合物2.6997±0.0021%。氨基酸分析显示氨基酸谱丰富，其中赖氨酸和谷氨酸分别是主要的必需氨基酸和非必需氨基酸。脂肪酸分析表明C14:1n5占主导地位。这些发现强调了NDS作为高质量膳食蛋白补充剂的潜力，并为其工业化规模生产提供了坚实基础。
