细菌素
乳酸
植物乳杆菌
食品科学
细菌
微生物学
益生菌
乳酸菌
短乳杆菌
基因
发酵
鼠李糖乳杆菌
乳球菌
作者
Stamatia Asimakoula,Katerina Giaka,Christos Fanitsios,Athanasia Kakouri,Elpiniki Vandera,John Samelis,Anna-Irini Koukkou
出处
期刊:Journal of Food Protection
[International Association for Food Protection]
日期:2021-03-01
卷期号:84 (3): 509-520
被引量:2
摘要
ABSTRACT When developing protective starter cultures for application in cheese technologies, monitoring growth interactions between starter and adjunct lactic acid bacterial (LAB) species and in situ expression of bacteriocin genes in the mixtures is crucial. This study first aimed to monitor the growth of mixed LAB strain populations during milk model fermentations by microbial counts and real-time quantitative PCR. The primary starter strains, Streptococcus thermophilus ST1 and costarter Lactococcus lactis subsp. cremoris M78, served as the basic starter composite coinoculated in all milk treatments. Adjunct bacteriocinogenic Enterococcus faecium strains KE82 and GL31 and the ripening Lactiplantibacillus plantarum H25 strain were added separately to the starter composite, resulting in four LAB combination treatments. The second aim was to quantify gene transcripts of nisin and enterocins B and A synthesized by strains M78, KE82, and GL31, respectively, by reverse transcription-real-time quantitative PCR and to detect the in situ antilisterial effects of the cocultures. Adjunct LAB strains showed growth compatibility with the starter, since all of them exhibited 2- to 3-log-unit increases in their population levels compared to their initial inoculation levels, with ST1 prevailing in all treatments. KE82 grew more competitively than GL31, whereas cocultures with KE82 displayed the strongest in situ antilisterial activity. Nisin gene expression levels were higher at the exponential phase of microbial growth in all treatments. Finally, the expression levels of nisin and enterocin A and B genes were interrelated, indicating an antagonistic activity. HIGHLIGHTS
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