![]() InĪddition, fungi tend to rapidly invade agar surfaces, covering small yeast colonies and resulting in an underestimation of One limitation of enumerating yeasts and molds on traditionalĪgar media is that hyphae are multicellular structures, and colonies on a petri dish rarely develop from single cells. The fungal microbiota of bloomy-rind cheeses, such as Camembert, forms a complex ecosystem that has not been well studied,Īnd its monitoring during the ripening period remains a challenge. These data provide further advances in our knowledge about the biological activities of the dominant ripening microflora of Camembert cheese and will help select biological markers to improve cheese quality assessment. Relative expression data showed that these functions occurred mostly in the first two weeks of the ripening period. According to the functional annotation performed, the predominant processes during Camembert ripening include gene expression, energy-, carbohydrate-, organic acid-, lipid- and protein- metabolic processes, cell growth, and response to different stresses. Sequence analysis revealed that 57% of the contigs could be affiliated to molds, 16% originated from yeasts, and 27% could not be identified. A database called CamemBank01was generated, containing a total of 1,060,019 sequence tags (reads) assembled in 7916 contigs. The metatranscriptome of an industrial Canadian Camembert-type cheese was studied at seven different sampling days over 77 days of ripening. #PUR SUBMERGE CODE#However, very little is known about the genetic determinants that code for these activities and their expression profile over time during the ripening process. camemberti is responsible for the white and bloomy aspect of the rind, and produces enzymes involved in proteolysis and lipolysis activities. candidum reduces bitterness, enhances sulphur flavors through amino acid catabolism and has an impact on rind texture, firmness and thickness, while P. These species are major contributors to the texture and flavour of typical bloomy rind cheeses. camembertii (3.7 and 5.5 g/l, respectively), for which continuous proteolysis and assimilation of peptides were shown.Ĭamembert-type cheese ripening is driven mainly by fungal microflora including Geotrichum candidum and Penicillium camemberti. camembertii (0.19 and 0.08 g/l/h, respectively) by assimilating the most readily utilizable peptides and amino acids however, owing to its lower proteolytic activity, the maximum biomass was lower than that of P. candidum preferred peptides and amino acids to lactate as energy sources, in addition to being assimilated as carbon and nitrogen sources. camembertii growth, since throughout growth, lactate was only dissimilated, viz., used for energy supply by oxidation into CO2, whereas peptides and amino acids from peptones were used for carbon (and nitrogen) assimilation. Similar to the behavior previously recorded on a simple substrate (glutamate), a clear differentiation between the carbon source and the energy source was also shown on peptones and lactate during P. The behavior of Penicillium camembertii and Geotrichum candidum growing in submerged pure cultures on simple (glutamate) or complex (peptones) substrates as nitrogen and carbon sources and an lactate as a second carbon source was examined. ![]()
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