Öztürk Hüseyin, Geniş Burak, Özden Tuncer Banu, Tuncer Yasin
Department of Food Technology, Manavgat Vocational School, Akdeniz University, 07600, Antalya, Turkey.
Faculty of Engineering, Department of Food Engineering, Süleyman Demirel University, 32260, Isparta, Turkey.
Vet Res Commun. 2023 Sep;47(3):1321-1345. doi: 10.1007/s11259-023-10080-7. Epub 2023 Feb 4.
Enterococci are lactic acid bacteria (LAB) that play a role in the aroma formation, maturation, and sensory development of fermented foods such as meat and dairy products. They also contribute to the improvement of the extended shelf life of fermented foods by producing bacteriocin. The aim of this study was to isolate bacteriocin-producing LAB from sheep and goat colostrum, to characterize the bacteriocin-producing strains, and determine the technological properties of the strains. A total of 13 bacteriocin-producing LAB was isolated and identified as 11 Enterococcus mundtii and two Enterococcus faecium. The strains were found to be genetically different from each other by phylogenetic analysis of 16S rRNA gene sequences and random amplified polymorphic-DNA (RAPD-PCR). It has been determined that bacteriocins show activity in a wide pH range and are resistant to heat, lose their activity with proteolytic enzymes and α-amylase, but are resistant to detergents. While the presence of the munKS gene was detected in all of the strains, it was determined that E. faecium HC121.4, HC161.1, E. mundtii HC147.1, HC166.5, and HC166.8 strains contained multiple enterocin genes. Trisin-SDS-PAGE analysis revealed two active protein bands of approximately 5.1 and 5.5 kDa in E. faecium HC121.4 and one active protein band with a weight of approximately 4.96 kDa in other strains. E. mundtii strains and E. faecium HC161.1 were identified as mundticin KS producers, and E. faecium HC121.4 was defined as an enterocin A and B producer. Except for E. mundtii HC166.8, acid production of strains was found to be slow at 6 h and moderate at 24 h. None of them showed extracellular proteolytic and lipolytic activities. It was found that the strains had esterase, esterase lipase, leucine arylamidase, acid phosphatase, and naphthol-AS-Bl-phosphohydrolase activities, while protease activities were low and peptidase activities were high. In conclusion, bacteriocin producer 13 Enterococcus strains isolated from sheep and goat colostrum were found to have the potential to be included in starter culture combinations.
肠球菌是乳酸菌，在肉类和乳制品等发酵食品的香气形成、成熟和感官发展中发挥作用。它们还通过产生细菌素有助于延长发酵食品的货架期。本研究的目的是从绵羊和山羊初乳中分离产细菌素的乳酸菌，鉴定产细菌素的菌株，并确定这些菌株的工艺特性。共分离出13株产细菌素的乳酸菌，鉴定为11株蒙氏肠球菌和2株粪肠球菌。通过16S rRNA基因序列的系统发育分析和随机扩增多态性DNA（RAPD-PCR）发现这些菌株在基因上彼此不同。已确定细菌素在很宽的pH范围内具有活性，耐热，在蛋白水解酶和α-淀粉酶作用下失去活性，但对洗涤剂有抗性。虽然在所有菌株中都检测到munKS基因，但确定粪肠球菌HC121.4、HC161.1、蒙氏肠球菌HC147.1、HC166.5和HC166.8菌株含有多个肠球菌素基因。Trisin-SDS-PAGE分析显示，粪肠球菌HC121.4中有两条活性蛋白带，分子量约为5.1和5.5 kDa，其他菌株中有一条活性蛋白带，分子量约为4.96 kDa。蒙氏肠球菌菌株和粪肠球菌HC161.1被鉴定为蒙地菌素KS生产者，粪肠球菌HC121.4被定义为肠球菌素A和B生产者。除蒙氏肠球菌HC166.8外，菌株在6小时产酸缓慢，在24小时产酸适中。它们均未表现出细胞外蛋白水解和脂肪分解活性。发现这些菌株具有酯酶、酯酶脂肪酶、亮氨酸芳基酰胺酶、酸性磷酸酶和萘酚-AS-Bl-磷酸水解酶活性，而蛋白酶活性低，肽酶活性高。总之，从绵羊和山羊初乳中分离出的13株产细菌素的肠球菌菌株有潜力被纳入发酵剂组合中。
