Presence of halophilic and alkaliphilic lactic acid bacteria in various cheeses


    loading  Checking for direct PDF access through Ovid

Abstract

AimWe sought to confirm the presence of halophilic and alkaliphilic lactic acid bacteria (HALAB) of marine origin in cheeses and thus contribute to the understanding of the roles of LAB flora in cheese ripening.Methods and ResultsWe used 7% NaCl glucose–yeast extract–peptone–fish extract broth and agar media (pH 9·5) for pour-plating and enrichment culture for 16 cheese samples produced in six European countries. HALAB were present in 9 of the 16 samples at <20–>107 CFU g−1. In three mould-ripened soft cheeses, HALAB counts ranged from 106 to 107 CFU g−1 and were one order (two samples) and six orders (one sample) of magnitude greater than that of nonhaloalkaliphilic, common LAB, as enumerated on lactobacilli MRS agar. The 16S rRNA gene sequences (500 bp) of 51 of the 55 isolates examined were identical or similar to that of Marinilactibacillus psychrotolerans or Alkalibacterium olivapovliticus and related species, all of which are HALAB.ConclusionsHALAB of possible marine origin were present in various soft, semi-hard and semi-soft cheeses and were highly predominant in some mould-ripened cheeses.Significance and Impact of the StudyHALAB of possible marine origin are members of the microflora of various cheeses and, when dominant, may play a role in the ripening of cheeses. Microbial analysis of LAB flora in cheeses should take into consideration the presence of HALAB.

    loading  Loading Related Articles