副干酪乳杆菌HD1.7高密度培养产细菌素Paracin1.7条件优化

在东北酸菜中发现的副干酪乳杆菌(Lactobacillus paracasei) HD1.7发酵液中含有细菌素Paracin1.7,凭借其较广的抑菌谱,有潜力成为新型的食品防腐剂,本研究旨在提高细菌素Paracin1.7的产量。以副干酪乳杆菌HD1.7为出发菌种,利用发酵罐高密度培养进行单因素发酵条件优化和正交试验设计,提高细菌素Paracin1.7的产量。结果表明,发酵过程中,最佳接种量为3%,最佳接种龄为18 h,最佳装液量为2 L/3.7 L,最佳初始pH 5.5,最佳通气量为0 L/min,最佳转速为400 r/min、最佳培养温度为35℃、最佳培养时间为24 h。在上述优化条件下,获得的发酵液中细菌素Paracin1.7的效价由优化前的863.01±39.77 AU/mL提高到978.46±7.16 AU/mL,是原始的1.13倍,菌体密度达到1010CFU/mL。通过优化发酵条件,能显著提高副干酪乳杆菌HD1.7生物量及细菌素产量,且为设计和改进高密度培养菌体奠定了试验基础。

The Production of Bacteriocin Paracin1.7 by High-density Culture of Lactobacillus paracasei HD1.7: Condition Optimization

The fermentation broth of Lactobacillus paracasei HD1.7 found in the Chinese sauerkraut contains bacteriocin Paracin 1.7, it has the potential to become a new type of food preservative depending on its broad spectrum of inhibition. This study aims to increase the yield of bacteriocin Paracin1.7. Using L. paracasei HD1.7 as the starting strain, high-density culture of fermenter was used to optimize single-factor fermentation conditions and conduct orthogonal design to increase the yield of bacteriocin Paracin1.7. The results showed that during the fermentation process, the optimal inoculum was 3%, the optimal inoculum age was 18 h, the optimal liquid volume was 2 L/3.7 L, the optimal initial pH value was pH 5.5, and the optimal aeration was 0 L/min, the optimal rotational speed was 400 r/min, the optimal culture temperature was 35℃, and the optimal culture time was 24 h. Under the above optimized conditions, the titer of bacteriocin Paracin 1.7 in the fermentation broth was increased from 863.01±39.77 AU/mL before optimization to 978.46±7.16 AU/mL, which was 1.13 times of the original, and the density of the bacteria reached 10¹⁰ CFU/mL. By optimizing the fermentation conditions, the biomass and bacteriocin production of L. paracasei HD1.7 can be significantly improved, and the experimental basis for designing and improving high-density cultured cells is laid.