Department of Chemical and Environmental Engineering, University of Oviedo, Faculty of Chemistry, C/Julián Clavería S/N, 33071, Oviedo, Spain.
Bioprocess Biosyst Eng. 2020 Jan;43(1):55-66. doi: 10.1007/s00449-019-02204-8. Epub 2019 Oct 30.
Pseudomonas taetrolens constitutes an efficient platform for the biosynthesis of lactobionic acid, a potentially prebiotic compound. Unfortunately, an amensalistic interaction has been demonstrated between P. taetrolens and probiotic lactic acid bacteria (LAB), characterized by the competitive exclusion of P. taetrolens, hindering the in situ production of fermented dairy products with synbiotic properties. In the present research, encapsulation was explored as a barrier to the diffusion of the antimicrobial metabolites generated by LAB. Mixed fermentations involving P. taetrolens LMG 2336 and Lactobacillus casei CECT 475 were cultivated, entrapping both microorganisms alternately. Alginate, alginate/starch and carboxymethyl cellulose/k-carrageenan were tested as encapsulating agents. The immobilization of L. casei in 2% alginate/2% starch beads was found to be the best strategy, improving the production of lactobionic acid by 182% with respect to co-cultures with free cells. This study proves the potential of LAB encapsulation for the protection of sensitive strains in mixed food fermentations.
产碱假单胞菌是合成乳糖酸的有效平台，乳糖酸是一种有潜在益生元特性的化合物。不幸的是，产碱假单胞菌和益生菌乳酸菌（LAB）之间存在一种共栖相互作用，其特征是产碱假单胞菌被竞争性排除，阻碍了具有共生特性的发酵乳制品的原位生产。在本研究中，我们探索了封装作为 LAB 产生的抗菌代谢物扩散的屏障。进行了涉及产碱假单胞菌 LMG 2336 和干酪乳杆菌 CECT 475 的混合发酵，交替包封这两种微生物。测试了藻酸盐、藻酸盐/淀粉和羧甲基纤维素/κ-卡拉胶作为包封剂。发现将干酪乳杆菌固定在 2%藻酸盐/2%淀粉珠中是最佳策略，与游离细胞的共培养相比，乳糖酸的产量提高了 182%。这项研究证明了 LAB 包封用于保护混合食品发酵中敏感菌株的潜力。
