Lactic acid bacteria isolated from Arzua cows' milk cheese

A total of 302 lactic acid bacteria (LAB) isolates were obtained from samples taken at various stages during manufacture and ripening of Arzua cheese (a traditional) raw cows' milk cheese from northwest Spain). Of the 302 isolates, 121 were identified as Lactococcus lactis subsp. lactis, 49 as Lactobacillus casei, six as Lb. plantarum, 49 as Leuconostoc mesenteroides, 22 as Ln. paramesenteroides and one as Ln. lactis. Forty-six isolates were identified as enterocci. Between the start of mnaufacture and day 15 of ripening, Lactococcus isolates were the most numerous,. towards the end of ripening, lactococci and lactobacilli isolates were about equally frequent. The majority of the lactococci isolates had weak acidifying and slow milk-coagulating activities. Most lactobacilli were weakly proteolytic, and unconventional biochemical characteristics were very frequent among these isolates. Of the leuconostocs isolates, only that identified as Ln. lactis produced acetoin from citrate.