The overall composition of the Clostridium tyrobutyricum cell envelope did not vary significantly during cell growth and was characterized by a high protein content (about 40% dry weight). Teichoic ...and teichuronic acids were absent and the neutral sugar content low. Insoluble peptidoglycan represented only 10-12% of the cell envelope (dry weight basis); it contained glucosamine, muramic acid, alanine, diaminopimelic acid and glutamic acid (molecular ratio 1/1/2/1/1). SDS-PAGE revealed the presence of about 50 proteins in this cell envelope; however, one high molecular weight protein was largely predominant. They were not covalently bound to the peptidoglycan and their relative amounts were practically constant through cell growth and with various extraction treatments. A brief heat treatment of whole cells in PBS caused selective release of the major cell envelope proteins together with flagellin; this method was used to characterize these proteins in 37 strains of C. tyrobutyricum and some other clostridia. The major envelope proteins had molecular weights ranging from 96 to 145 Kd and the flagellins from 32 to 72 Kd.
The bacteria responsible of Mozzarella cheese discolorations and causing blowing of melted cheeses were identified and are here described. They are, respectively, Pantoea agglomerans, P. gessardii ...(yellow-violet discoloration), Plantibacter flavus and Plantibacter agrosticola (pink discoloration) and C. tyrobutyricum (blowing of melted cheese)
Sono stati identificati e vengono descritti i batteri responsabili delle chiazzature di mozzarelle e del rigonfiamento di formaggi fusi. I germi identificati sono stati, per la formazione di macchie colorate a danno di mozzarelle, Pantoea agglomerans e P. gessardii, Plantibacter flavus e Plantibacter agrosticola e, causa del rigonfiamento di formaggi fusi, C. tyrobutyricum
