PDF(Pubmed)
Abstract：
Staka is a traditional Greek sour cream made mostly from spontaneously fermented sheep milk or a mixture of sheep and goat milk. At the industrial scale, cream separators and starter cultures may also be used. Staka is sometimes cooked with flour to absorb most of the fat. In this study, we employed culture-based techniques, amplicon sequencing, and shotgun metagenomics to analyze the Staka microbiome for the first time. The samples were dominated by Lactococcus or Leuconostoc spp. Most other bacteria were lactic acid bacteria (LAB) from the Streptococcus and Enterococcus genera or Gram-negative bacteria from the Buttiauxella, Pseudomonas, Enterobacter, Escherichia-Shigella, and Hafnia genera. Debaryomyces, Kluyveromyces, or Alternaria were the most prevalent genera in the samples, followed by other yeasts and molds like Saccharomyces, Penicillium, Aspergillus, Stemphylium, Coniospotium, or Cladosporium spp. Shotgun metagenomics allowed the species-level identification of Lactococcus lactis, Lactococcus raffinolactis, Streptococcus thermophilus, Streptococcus gallolyticus, Escherichia coli, Hafnia alvei, Streptococcus parauberis, and Enterococcus durans. Binning of assembled shotgun reads followed by recruitment plot analysis of single reads could determine near-complete metagenome assembled genomes (MAGs). Culture-dependent and culture-independent analyses were in overall agreement with some distinct differences. For example, lactococci could not be isolated, presumably because they had entered a viable but not culturable (VBNC) state or because they were dead. Finally, several LAB, Hafnia paralvei, and Pseudomonas spp. isolates exhibited antimicrobial activities against oral or other pathogenic streptococci, and certain spoilage and pathogenic bacteria establishing their potential role in food bio-protection or new biomedical applications. Our study may pave the way for additional studies concerning artisanal sour creams to better understand the factors affecting their production and the quality.
摘要：
Staka是一种传统的希腊酸奶油，主要由自发发酵的羊奶或羊奶和羊奶的混合物制成。在工业规模上,也可以使用奶油分离器和发酵剂培养物。Staka有时用面粉煮熟以吸收大部分脂肪。在这项研究中,我们采用了基于文化的技术，扩增子测序，和猎枪宏基因组学首次分析了Staka微生物组。样品以乳球菌或明串珠菌属为主。大多数其他细菌是来自链球菌和肠球菌属的乳酸菌（LAB）或来自Buttiauxella的革兰氏阴性细菌，假单胞菌,肠杆菌,大肠杆菌志贺氏菌,和哈夫尼亚属。去细菌,克鲁维酵母,或者链格孢是样本中最普遍的属，其次是其他酵母和霉菌，如酵母，青霉,曲霉菌,茎phylium,孢子孢子,或枝孢菌属。shot弹枪宏基因组学允许对乳酸乳球菌进行物种级鉴定，棉子乳球菌,嗜热链球菌,溶胆链球菌,大肠杆菌,哈夫尼亚肺泡，副链球菌,和durans肠球菌.组装的shot弹枪读段的合并，然后是单个读段的招募图分析，可以确定接近完整的宏基因组组装的基因组（MAG）。文化依赖和文化独立分析总体上是一致的，有一些明显的差异。例如,不能分离乳球菌,大概是因为他们进入了可行但不可培养的（VBNC）状态，或者是因为他们已经死亡。最后,几个实验室,Hafniaparalgivi,和假单胞菌属。分离株对口腔或其他致病性链球菌表现出抗菌活性，以及某些腐败和致病菌在食品生物保护或新的生物医学应用中确立了潜在的作用。我们的研究可能为有关手工酸液的其他研究铺平道路，以更好地了解影响其生产和质量的因素。
