Selenium (Se), which is present as SeCys in seleno-proteins, is involved in cancer prevention, thyroid functioning, and pathogen inhibition. Se is incorporated in the diet through Se-containing foods. Some lactic acid bacteria (LAB) can biotransform selenite (toxic) into Se-nanoparticles (SeNPs) and Se-amino acids. To exert their beneficial properties in the host, bacteria should survive the harsh conditions of the gastrointestinal tract and during food storage. We evaluated whether selenization of LAB influenced bacterial growth and survival during gastrointestinal digestion and after storage when present in a fermented fruit juice-milk (FJM) beverage. Lactobacillus brevis CRL 2051 and Fructobacillus tropaeoli CRL 2034 were grown in MRS with and without selenite, and used to inoculate the FJM matrix. Selenization had no effect on LAB growth (9.54-9.9 log CFU/mL) in the FJM drink. The presence of SeNPs was confirmed for both selenized strains in the FJM beverage; however, the highest Se concentration (100 μg/L) was detected for the fermented beverage with selenized L. brevis. Under storage conditions 1.1 log CFU/ml decrease in cell count of selenized cells of L. brevis was observed, while no effect on cell viability was detected for non-selenized L. brevis or both selenized and control cells of F. tropaeoli. Resistance of L. brevis during digestion of the fermented FJM beverage was not affected by selenization. Contrarily, an increase (1 log CFU/mL) in the resistance of F. tropaeoli was observed when cells were selenized. After digestion, Se was detected in the soluble fraction of the beverage fermented by both strains, being higher for L. brevis (23.6 μg/L). Although selenization did not exert a drastic effect on strains´ survival during storage and digestion, microbial selenization previous to food fermentation could be an interesting tool for Se enrichment avoiding thus the addition of toxic Se salts.

中文翻译：

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富含硒的乳酸菌在发酵饮料中的储存和模拟肠胃消化的存活率。

硒（Se）以硒蛋白形式存在于硒蛋白中，参与癌症预防，甲状腺功能和病原体抑制。硒是通过含硒食物掺入饮食中的。一些乳酸菌（LAB）可以将亚硒酸盐（有毒）生物转化为硒纳米颗粒（SeNPs）和硒氨基酸。为了在宿主中发挥其有益的特性，细菌应在胃肠道的恶劣条件下和食品储存过程中幸存下来。我们评估了LAB的硒化是否影响胃肠道消化过程中以及发酵果汁牛奶（FJM）饮料中储存后细菌的生长和存活。短乳杆菌CRL 2051和tropeubacoli tropaeoli CRL 2034在含或不含亚硒酸盐的MRS中生长，并用于接种FJM基质。硒化对LAB的生长没有影响（9。FJM饮料中的含量为54-9.9 log CFU / mL）。在FJM饮料中，两种硒化菌株均证实了SeNPs的存在。但是，硒化短乳杆菌的发酵饮料检测到最高的硒浓度（100μg/ L）。在储存条件下，观察到短乳杆菌的硒细胞的细胞计数降低1.1log CFU / ml，而未硒化的短乳杆菌或对虾F. tropaeoli的硒细胞和对照细胞均未检测到对细胞活力的影响。发酵的FJM饮料在消化过程中的短乳杆菌抵抗力不受硒化的影响。相反地​​，当细胞被硒化时，观察到对白对虾的抗性增加（1log CFU / mL）。消化后，在两种菌株发酵的饮料的可溶级分中均检测到硒，对于短乳杆菌（L. brevis）更高（23.6μg/ L）。