Brevibacterium aurantiacum 8(6) and Hafnia alvei GB001, monocultures and cocultures Transcriptome

Iron is an essential micronutrient for most microorganisms, participating in numerous metabolic pathways. In cheese, iron is present in limited concentrations, making it an important point for microbial interactions. Some bacteria produce high affinity iron-scavenging molecules called siderophores to sequester iron from the environment. Brevibacterium aurantiacum and Hafnia alvei are two important ripening bacteria that contribute to the organoleptic characteristics of cheese. B. aurantiacum cannot synthesize its own siderophores, but relies on those produced by H . alvei. In turn, H. alvei which has low proteolytic activity, depends on the proteases of B. aurantiacum to access nitrogen sources. To investigate this mutualistic relationship, we cultivated the two species in a cheese-like synthetic medium under both low-iron and iron-sufficient conditions, in mono- and co-culture.