Reference 2D maps of Clostridium tyrobutyricum endospores and germinative forms isolated from cow milk used for Grana Padano production

Introduction.The change which more frequently affects production of semi-hard and hard cheeses such as Grana Padano is known as “late swelling” or “blowing”.This phenomenon, if marked, may affect the structure of the cheese and can be accompanied by unpleasant taste and odour due to the production of butyric acid and acetic aldehyde.The late appearance of the swelling is related to the number of spores, in particular from Clostridium tyrobutyricum, initially present in milk[1].Little is known about proteins that enhance germination and metabolic changes in C. tyrobutyricum[2]. Thus, proteomic understanding of the initial stages of germination may help to prevent the late blowing phenomenon. Aim of this study is the definition of a 2D reference map for endospores and germinative forms of C. tyrobutyricum.Methods. Bacterialsamples isolated from milk were subjected to 1-DE and 2-DE and all proteins separated from each experimental condition were identified by mass spectrometry. Results. The effects of germination on protein expression were studied with two-dimensional protein electrophoresis (2DE). There were about 400 protein spots on the 2-DE maps obtained for both the endospore and germinative form. These 2-DE protein maps were analyzed with the ProgenesisSameSpot 3.3 software (Nonlinear Dynamics), which compared and identified proteins with changed expression levels between experimental conditions Conclusion.Proteomic data obtained from this study, may provide a reference 2D map of C. tyrobutyricum endospores and germinative forms and additional information for elucidating proteins involved in early germination of C. tyrobutyricum endospores.