Novin Donya, Seifan Mostafa, Ebrahiminezhad Alireza, Berenjian Aydin
School of Engineering, The University of Waikato, Hamilton, 3216, New Zealand.
Department of Medical Nanotechnology, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran.
Bioprocess Biosyst Eng. 2021 Jan;44(1):39-45. doi: 10.1007/s00449-020-02417-2. Epub 2020 Jul 30.
Probiotics, in particular, lactic acid bacteria (LAB) are widely used as starter cultures in food and pharmaceutical industries. Presence of LAB supports the production and preservation of a diverse range of food products, provides a positive effect on the human gastrointestinal tract, and prevents the progression of many diseases. However, the main limiting factor in the application of LAB is that they hardly survive in acidic conditions, including the human digestive system. This factor inhibits LAB to maintain their functionality and deliver their health benefits to the host. For this purpose, magnetic immobilisation of LAB with iron oxide nanoparticles (IONs) was conducted to evaluate the effect of IONs on bacterial growth and their viability at low pH. Gram-positive Lactobacillus acidophilus, a well-known species of LAB, was selected for this study. The IONs were successfully synthesised with the average size of 7 nm and used for decoration of L. acidophilus cells at low pH. Based on the results, a 1.8-fold increase in bacterial viability was observed by decorating cells with 360 µg/mL IONs.
益生菌，尤其是乳酸菌（LAB），在食品和制药行业中被广泛用作发酵剂。乳酸菌的存在有助于生产和保存各种食品，对人体胃肠道有积极影响，并能预防多种疾病的发展。然而，乳酸菌应用的主要限制因素是它们在酸性条件下很难存活，包括人体消化系统。这一因素抑制了乳酸菌维持其功能并将健康益处传递给宿主。为此，进行了用氧化铁纳米颗粒（IONs）对乳酸菌进行磁性固定化的实验，以评估IONs对细菌生长及其在低pH值下生存能力的影响。本研究选用了革兰氏阳性嗜酸乳杆菌，这是一种著名的乳酸菌。成功合成了平均尺寸为7纳米的IONs，并用于在低pH值下修饰嗜酸乳杆菌细胞。结果表明，用360微克/毫升的IONs修饰细胞后，细菌的生存能力提高了1.8倍。
