Federal University of San Francisco Valley, Rod. BR 407, Km 12 - Lote 543 - Projeto de Irrigação Senador Nilo Coelho, s/nº - C1, 56.300-990, Petrolina, Pernambuco, Brazil.
Federal University of Lavras, Biology Department, 37.200-000, Lavras, Minas Gerais, Brazil.
Food Microbiol. 2016 Dec;60:29-38. doi: 10.1016/j.fm.2016.06.014. Epub 2016 Jun 24.
This study aimed to select autochthonous lactic acid bacteria (LAB) with probiotic and functional properties from goat dairies and test their addition to artisanal cheese for the inhibition of Salmonella typhi. In vitro tests, including survival in the gastrointestinal tract (GIT), auto- and co-aggregation, the hemolytic test, DNase activity, antimicrobial susceptibility, antibacterial activity, tolerance to NaCl and exopolysaccharide (EPS), gas and diacetyl production were conducted for sixty isolates. Based on these tests, four LAB isolates (UNIVASF CAP 16, 45, 84 and 279) were selected and identified. Additional tests, such as production of lactic and citric acids by UNIVASF CAP isolates were performed in addition to assays of bile salt hydrolase (BSH), β-galactosidase and decarboxylase activity. The four selected LAB produced high lactic acid (>17 g/L) and low citric acid (0.2 g/L) concentrations. All selected strains showed BSH and β-galactosidase activity and none showed decarboxylase activity. Three goat cheeses (1, 2 and control) were produced and evaluated for the inhibitory action of selected LAB against Salmonella typhi. The cheese inoculated with LAB (cheese 2) decreased 0.38 log10 CFU/g of S. Typhy population while in the cheese without LAB inoculation (cheese 1) the pathogen population increased by 0.29 log units. Further, the pH value increased linearly over time, by 0.004 units per day in cheese 1. In the cheese 2, the pH value decreased linearly over time, by 0.066 units per day. The cocktail containing selected Lactobacillus strains with potential probiotic and technological properties showed antibacterial activity against S. typhi in vitro and in artisanal goat cheese. Thus, goat milk is important source of potential probiotic LAB which may be used to inhibit the growth of Salmonella population in cheese goat, contributing to safety and functional value of the product.
本研究旨在从山羊乳中筛选具有益生菌和功能特性的本土乳酸菌（LAB），并将其添加到手工奶酪中，以抑制伤寒沙门氏菌。进行了包括在胃肠道（GIT）中的生存能力、自聚集和共聚集、溶血试验、DNase 活性、抗菌敏感性、抗菌活性、耐盐和胞外多糖（EPS）、气体和二乙酰生产在内的 60 株分离株的体外测试。基于这些测试，选择并鉴定了四种 LAB 分离株（UNIVASF CAP16、45、84 和 279）。此外，还进行了 UNIVASF CAP 分离株产生乳酸和柠檬酸的生产测试，以及胆汁盐水解酶（BSH）、β-半乳糖苷酶和脱羧酶活性的测定。四种选定的 LAB 产生了高浓度的乳酸（>17g/L）和低浓度的柠檬酸（0.2g/L）。所有选定的菌株均表现出 BSH 和 β-半乳糖苷酶活性，且均无脱羧酶活性。制作了三种山羊奶酪（1、2 和对照），并评估了所选 LAB 对伤寒沙门氏菌的抑制作用。接种 LAB 的奶酪（奶酪 2）使 S. Typhi 种群减少了 0.38log10CFU/g，而未接种 LAB 的奶酪（奶酪 1）中病原体种群增加了 0.29log 单位。此外，奶酪 1 的 pH 值随时间呈线性增加，每天增加 0.004 个单位。在奶酪 2 中，pH 值随时间呈线性下降，每天下降 0.066 个单位。含有潜在益生菌和技术特性的选定乳杆菌菌株的鸡尾酒在体外和山羊乳奶酪中均表现出对 S.typhi 的抗菌活性。因此，山羊奶是潜在益生菌 LAB 的重要来源，可用于抑制奶酪山羊中沙门氏菌种群的生长，从而提高产品的安全性和功能性价值。
