BB-kb@ldeleger:BB-kb-F-23224222-002 JSONTXT

During the initial ripening period, yeasts (primarily Debaryomyces hansenii for semi-soft cheeses and additionally Geotrichum candidum for soft cheeses) and coagulase-negative staphylococci (Staphylococcus equorum) are present [3, 21, 26]. Generally, D. hansenii and staphylococci on cheese surface are assumed to originate from the cheese brine, which often is not changed or pasteurised between salting of different batches [2, 3, 42]. For D. hansenii, Petersen et al. [46] showed that the dominating D. hansenii strain on cheeses of the Danish Danbo type did not originate from the added ripening culture, but from the dairy housemicrobiota present in the ripening room. D. hansenii is important during cheese ripening as it assimilates lactate and produces alkaline metabolites such as ammonia thereby increasing pH of the cheese surface [23, 46], which enables the growth of the less acid tolerant bacterial microbiota, primarily Gram-positive coryneforms (Brevibacterium spp., Corynebacterium spp. and Microbacterium spp.) [4]. In addition, subpopulations of bacteria such as Gram-positive Marinilactibacillus spp. and Gram-negative Halomonas spp., Vibrio spp. and Proteus spp., and bacteria of the Enterobacteriaceae family have been reported to occur on cheese surfaces [14, 15, 25, 34, 35, 41, 50]. The presence of Gram-negative bacteria was first hypothesised to be indicative of hygienic problems. However, more recent results have shown that they produce important cheese flavour compounds and thus might contribute positively to the cheese ripening process [11].