Huang Song, Gaucher Floriane, Cauty Chantal, Jardin Julien, Le Loir Yves, Jeantet Romain, Chen Xiao Dong, Jan Gwénaël
Suzhou Key Laboratory of Green Chemical Engineering, School of Chemical and Environmental Engineering, College of Chemistry, Chemical Engineering and Material Science, Soochow University, Jiangsu, China.
UMR1253 STLO, Agrocampus Ouest, INRA, Rennes, France.
Front Microbiol. 2018 Oct 22;9:2548. doi: 10.3389/fmicb.2018.02548. eCollection 2018.
BL23 has a recognized probiotic potential, which includes immune modulation, protection toward induced colitis, toward induced colon cancer and toward dissemination of pathogens. In , as well as in other probiotics, both probiotic and technological abilities are highly dependent (1) on the substrate used to grow bacteria and (2) on the process used to dry and store this biomass. Production and storage of probiotics, at a reasonable financial and environmental cost, becomes a crucial challenge. Food-grade media must be used, and minimal process is preferred. In this context, we have developed a "2-in-1" medium used both to grow and to dry BL23, considered a fragile probiotic strain. This medium consists in hyper-concentrated sweet whey (HCSW). BL23 grows in HCSW up to 30% dry matter, which is 6 times-concentrated sweet whey. Compared to isotonic sweet whey (5% dry matter), these growth conditions enhanced tolerance of BL23 toward heat, acid and bile salts stress. HCSW also triggered intracellular accumulation of polyphosphate, of glycogen and of trehalose. A gel-free global proteomic differential analysis further evidenced overexpression of proteins involved in pathways known to participate in stress adaptation, including environmental signal transduction, oxidative and metal defense, DNA repair, protein turnover and repair, carbohydrate, phosphate and amino acid metabolism, and in osmoadaptation. Accordingly, HCSW cultures of BL23 exhibited enhanced survival upon spray drying, a process known to drastically affect bacterial viability. This work opens new perspectives for sustainable production of dried probiotic lactobacilli, using food industry by-products and lowering energy costs.
BL23具有公认的益生菌潜力，包括免疫调节、对诱导性结肠炎、诱导性结肠癌以及病原体传播的保护作用。与其他益生菌一样，BL23的益生菌和技术能力高度依赖于：（1）用于培养细菌的底物；（2）用于干燥和储存这种生物质的过程。以合理的财务和环境成本生产和储存益生菌成为一项关键挑战。必须使用食品级培养基，并且优选最少的加工过程。在此背景下，我们开发了一种“二合一”培养基，用于培养和干燥被认为是脆弱益生菌菌株的BL23。这种培养基由超浓缩甜乳清（HCSW）组成。BL23在HCSW中生长至干物质含量达30%，即6倍浓缩甜乳清。与等渗甜乳清（干物质含量5%）相比，这些生长条件增强了BL23对热、酸和胆盐胁迫的耐受性。HCSW还引发了多磷酸盐、糖原和海藻糖在细胞内的积累。一项无凝胶的全局蛋白质组差异分析进一步证明，参与已知参与应激适应途径的蛋白质过表达，这些途径包括环境信号转导、氧化和金属防御、DNA修复、蛋白质周转和修复、碳水化合物、磷酸盐和氨基酸代谢以及渗透适应。因此，BL23的HCSW培养物在喷雾干燥后表现出更高的存活率，喷雾干燥是一个已知会严重影响细菌活力的过程。这项工作为利用食品工业副产品和降低能源成本可持续生产干燥益生菌乳酸菌开辟了新的前景。
