Laboratory of Microorganisms and Active Biomolecules (LMBA), Faculty of Sciences of Tunis, University of Tunis El-Manar, Tunisia; Research Laboratory of Environmental Science and Technology (RLEST), ISSTE, Technopole de Borj Cedria, Tunisia.
Institute of Sciences of Food Production, Italian National Research Council (CNR ISPA), Milan, Italy.
Microb Pathog. 2018 Apr;117:109-117. doi: 10.1016/j.micpath.2018.02.021. Epub 2018 Feb 10.
The aims of this study are to isolate new bacteriocinogenic lactic acid bacterial strains from white (Penaeus vannamei) and pink (Palaemon serratus) raw shrimps and evaluate their technological and probiotic potentialities. Seven strains were selected, among fifty active isolates, as producing interesting antimicrobial activity. Identified as Enterococcus lactis, these isolates were able to produce enterocins A, B and/or P. The safety aspect, assessed by microbiological and molecular tests, demonstrated that the strains were susceptible to relevant antibiotics such as vancomycin, negative for haemolysin and gelatinase activities, and did not harbour virulence and antibiotic resistance genes. The assessment of potential probiotic and technological properties showed a low or no lipolytic activity, moderate milk-acidifying ability, high reducing power, proteolytic activity and tolerance to bile (P < 0.05) and good autoaggregation and coaggregation capacities. Two strains designated as CQ and C43 exhibiting high enzymatic activities and bile salt hydrolase activity were found to display high survival under simulated in vitro oral cavity and gastrointestinal tract conditions caused by presence of lysozyme, pepsin, pancreatin, bile salts and acidic pH. This study highlights safe Enterococcus lactis strains with great technological and probiotic potentials for future application as new starter, adjunct, protective or probiotic cultures in food industry.
本研究的目的是从白对虾（Penaeus vannamei）和粉对虾（Palaemon serratus）生虾中分离新的产细菌素乳酸菌菌株，并评估它们的技术和益生菌潜力。从五十个活性分离株中选择了 7 株，这些分离株具有有趣的抗菌活性。这些被鉴定为肠球菌的分离株能够产生肠球菌 A、B 和/或 P。通过微生物学和分子测试评估的安全性表明，这些菌株对相关抗生素（如万古霉素）敏感，不具有溶血和明胶酶活性，也不携带毒力和抗生素耐药基因。对潜在益生菌和技术特性的评估表明，这些菌株具有低或无脂肪酶活性、中等的产酸能力、高还原力、蛋白酶活性和耐胆汁（P < 0.05）的特性，并且具有良好的自动聚集和共聚能力。发现被指定为 CQ 和 C43 的两个菌株具有较高的酶活性和胆汁盐水解酶活性，在存在溶菌酶、胃蛋白酶、胰酶、胆汁盐和酸性 pH 值的模拟体外口腔和胃肠道条件下具有较高的存活率。本研究突出了具有巨大技术和益生菌潜力的安全肠球菌菌株，可作为未来食品工业中新型发酵剂、添加剂、保护剂或益生菌的应用。
