title: Effect of temperature, pH, and water activity on Mucor spp. growth on synthetic medium, cheese analog and cheese.
abstract: The Mucor genus includes a large number of ubiquitous fungal species. In the dairy environment, some of them play a technological role providing typical organoleptic qualities to some cheeses while others can cause spoilage. In this study, we compared the effect of relevant abiotic factors for cheese production on the growth of six strains representative of dairy technological and contaminant species as well as of a non cheese related strain (plant endophyte). Growth kinetics were determined for each strain in function of temperature, water activity and pH on synthetic Potato Dextrose Agar (PDA), and secondary models were fitted to calculate the corresponding specific cardinal values. Using these values and growth kinetics acquired at 15 °C on cheese agar medium (CA) along with three different cheese types, optimal growth rates (μopt) were estimated and consequently used to establish a predictive model. Contrarily to contaminant strains, technological strains showed higher μopt on cheese matrices than on PDA. Interestingly, lag times of the endophyte strain were strongly extended on cheese related matrices. This study offers a relevant predictive model of growth that may be used for better cheese production control but also raises the question of adaptation of some Mucor strains to the cheese.
authors.affiliation: Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, ESIAB, Technopôle Brest Iroise, 29280 Plouzané, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Morin-Sardin
authors.affiliation: Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, ESIAB, Technopôle Brest Iroise, 29280 Plouzané, France.
authors.forename: Karim
authors.initials: K
authors.lastname: Rigalma
authors.affiliation: Université de Brest, EA3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, UMT Spore Risk, IUT Quimper, 6 Rue de l'Université, 29334 Quimper, France.
authors.forename: Louis
authors.initials: L
authors.lastname: Coroller
authors.affiliation: Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, ESIAB, Technopôle Brest Iroise, 29280 Plouzané, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Jany
authors.affiliation: Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, ESIAB, Technopôle Brest Iroise, 29280 Plouzané, France. Electronic address: emmanuel.coton@univ-brest.fr.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Coton
mesh_terms: D000222:Adaptation, Physiological; D002611:Cheese / Q000382:microbiology*; D003470:Culture Media / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D009089:Mucor / Q000145:classification / Q000254:growth & development* / Q000378:metabolism; D013696:Temperature; D014867:Water / Q000378:metabolism
chemical_list: D003470:Culture Media; D014867:Water
keywords: Abiotic factors; Adaptation; Cheese; Growth; Mucor; Predictive model