Department of Agricultural and Forestry Science, University of Palermo, Palermo, Italy.
Food Microbiol. 2013 Dec;36(2):343-54. doi: 10.1016/j.fm.2013.07.003. Epub 2013 Jul 18.
Lactic acid bacteria (LAB) were analysed from wheat flours used in traditional bread making throughout Sicily (southern Italy). Plate counts, carried out in three different media commonly used to detect food and sourdough LAB, revealed a maximal LAB concentration of approximately 4.75 Log CFU g(-1). Colonies representing various morphological appearances were isolated and differentiated based on phenotypic characteristics and genetic analysis by randomly amplified polymorphic DNA (RAPD)-PCR. Fifty unique strains were identified. Analysis by 16S rRNA gene sequencing grouped the strains into 11 LAB species, which belonged to six genera: Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and Weissella. Weissella cibaria, Lactobacillus plantarum, Leuconostoc pseudomesenteroides and Leuconostoc citreum were the most prevalent species. The strains were not geographically related. Denaturing gradient gel electrophoresis (DGGE) analysis of total DNA of flour was used to provide a more complete understanding of the LAB population; it confirmed the presence of species identified with the culture-dependent approach, but did not reveal the presence of any additional LAB species. Finally, the technological characteristics (acidifying capacity, antimicrobial production, proteolytic activity, organic acid, and volatile organic compound generation) of the 50 LAB strains were investigated. Eleven strains were selected for future in situ applications.
研究了西西里岛（意大利南部）传统面包制作中使用的小麦粉中的乳酸菌（LAB）。在三种常用于检测食品和酸面团 LAB 的不同培养基中进行平板计数，结果显示 LAB 的最大浓度约为 4.75 Log CFU g(-1)。分离出具有各种形态外观的菌落，并根据表型特征和随机扩增多态性 DNA（RAPD）-PCR 的遗传分析进行区分。鉴定出 50 株独特的菌株。16S rRNA 基因测序分析将菌株分为 11 种 LAB 物种，属于六个属：肠球菌、乳杆菌、乳球菌、明串珠菌、肠球菌和魏斯氏菌。魏斯氏菌 cibaria、植物乳杆菌、肠膜明串珠菌和柠檬明串珠菌是最常见的物种。这些菌株与地理位置无关。面粉总 DNA 的变性梯度凝胶电泳（DGGE）分析用于更全面地了解 LAB 种群；它证实了与培养相关方法鉴定的物种的存在，但未显示存在任何其他 LAB 物种。最后，研究了 50 株 LAB 菌株的技术特性（酸化能力、抗菌产物、蛋白水解活性、有机酸和挥发性有机化合物生成）。选择了 11 株菌株用于未来的原位应用。
