BIOCHEMICAL AND IMMUNOCHEMICAL CHARACTERIZATION OF PROTEIN PREPARATIONS OBTAINED BY DIFFERENT METHODS FROM GROUP-B NEISSERIA-MENINGITIDIS BIOMASS

Protein preparations containing group B N. meningitidis outer membrane peptides of classes 1 (44-47 kD), 2 (40-42 kD) and 5 (26-30 kD) have been obtained from the biomass of group B N. meningitidis, grown in a fermenter in a synthetic medium under the conditions of controlled cul tivation with regulated oxygen content and the intermittent drainage a nd filling of the fermenter and with the use of different extraction m ethods (lithium chloride extraction by the method of C. E. Frasch et a l.; sodium deoxycholate and potassium thiocyanate extraction). The che mical composition of these preparations and their peptide content have been shown to depend on the method of extraction; the preparation con taining the least amount of contaminating substances is obtained by ex traction with potassium thiocyanate. High-molecular fractions of these protein preparations, studied by the method of immunoblotting, contai n antigens cross-reacting with meningococcal sera, groups A and C.