Technological characterization of wild-typeLactococcus lactisstrains isolated from raw milk and traditional fermented milk products in Turkey

Abstract

The aim of this work was to detect technological characteristics of fifty strains of lactococci previously isolated in Turkey in order to use them as components of starter formulations. All the lactococcal strains were low acid producers from lactose except L. lactis subsp. lactis MBLL9. 22, 17 and 11 strains of L. lactis presented low, moderate and strong proteolytic activity, respectively. Three out of 50 strains (L. lactis subsp. lactis MBLL1, MBLL9 and MBLL57) were determined to be bacteriocin producers. The strains L. lactis subsp. lactis MBLL1 and MBLL9 were found to be lacticin 481-like producers, whereas MBLL57 was a nisin-like producer, according to their partial characterization data. L. lactis strains were tested against 61 lactic phages for their phage-resistance properties. Eleven strains exhibited a sensitive phenotype against different phages, whereas the remaining 39 strains were completely resistant to all phages. Among the L. lactis subsp. lactis biovar. diacetylactis strains, 5 strains were defined as high, 3 strains as medium and 7 strains as low-level diacetyl producers. L. lactis strains were found to have 1-10 plasmids with molecular weights from 1.9 to 29.2 kb. Lactococcus lactis / technological characteristics / plasmid / starter culture / wild strain

Optimisation of bacteriocin production of Lactococcus lactis subsp. lactis MA23, a strain isolated from Boza

“…The strain was previously isolated from Boza by the methods described in Özkalp et al. (2007) and identified as L .…”

“…The aim of this study was to characterise and determine the antimicrobial activity and conditions needed for optimal production of the bacteriocin by Lactococcus lactis subsp. lactis MA23, strain previously isolated from Boza (Özkalp et al. 2007).…”

The effects of incorporating wild-type strains of Lactococcus lactis into Turkish white-brined cheese (Beyaz peynir) on the fatty acid and volatile content

“…Raw bovine milk supplied from Harran University Dairy (Sanliurfa, Turkey) was used in cheesemaking. Lactococcus lactis strains were isolated from traditional Turkish dairy products including white‐brined cheeses, produced without using industrial starter cultures, in different regions of Turkey (Özkalp et al. 2007).…”

“…Diversity in cheese flavour has been narrowed, and the screening for new strains has become a subject of interest during the last two decades. In recent years, much effort has been made to isolate novel strains of L. lactis from natural environments and to characterise their industrial potentials (Özkalp et al. 2007).…”

“…This study investigated the role of wild strains of L. lactis (MBLL9, MBLL23 and MBL27) isolated from traditional Turkish dairy products on the development of free fatty acids (FFAs) and volatile compounds in Turkish white‐brined cheese. The wild strains used in this study were previously characterised by API ® 50 test and 16sRNA sequence analysis and published elsewhere (Özkalp et al. 2007).…”