No abstract

A slurry of brewer's yeast in beer was stored in two, 200-bbl cylindroconical vessels at 1.6° C. One was maintained full, while 34% of the yeast was removed from the other vessel after 24 hr. The yeast was stored in both vessels for a total of 80 hr. Samples were removed at intervals and analyzed for glycogen, trehalose, and viability. Aliquots of each yeast sample were pitched into 2 L of wort. Yeast glycogen and trehalose declined only slightly in the full vessel, but in the other vessel, glycogen declined significantly after removal of a portion of the yeast. Viability of the yeast stored by either method remained between 90 and 96%. Fermentations of the yeast stored by either method showed no relationship between yeast fermentation performance and glycogen or trehalose content. The fermentation performance of yeast stored under these industrial conditions was independent of glycogen or trehalose content and several reasons for this are discussed.

Localization of brucella antigens, to which brucella-infected cattle make antibodies, and the surface characteristics of Brucella abortus smooth strain 19 and rough strain 45/20 were studied by the use of monospecific antisera in absorption tests, electron microscopy, and electrophoretic mobility of organisms in microelectrophoresis. Antigenic determinants of electrophoretically defined antigen A5 were present on the surface of B. abortus rough strain 45/20 organisms, and protein moieties were most probably exposed on the surface of this strain in contrast with smooth strain 19 organisms. Several antigens distinct from the smooth lipopolysaccharide complex, to which brucella-infected cattle make antibodies, were not detected on the surface of smooth organisms. Agglutinating antibodies present in anti-B. abortus strain 19 serum did not bind to all areas on the surface of the smooth cells, suggesting the presence of different antigenic moieties on their surface. It is also postulated that the surface of B. abortus rough strain 45/20 displays receptors able to strongly bind immunoglobulin molecules, as well as other serum components. 1000 on July 16, 2020 by guest http://iai.asm.org/ Downloaded from 18. Wilson, G., and A. Miles. 1932. The serological differentiation of smooth strains of the Brucella group. Br.

No abstract

A suspension of Saccharomyces ceretisiae NCYC366 in buffered 1.2 M sorbitol containing Zymolyase-5000 (a ,/-glucanase-containing preparation) showed maximum osmotic sensitivity after 30 min of incubation at 30°C. A scanning electron microscope study of spheroplast formation, using a very high resolution (4-nm) machine, revealed several new morphological features. The surface of the plug in bud scars on intact cells appeared warty. The wall, which assumed a beady appearance as digestion proceeded, ultimately sloughed off to reveal the furrowed surface of the plasma membrane. Bud scars were resistant to digestion and, as incubation proceeded, they became surrounded by an outer annulus, which may be the secondary septum. Wall material was completely removed from the majority of cells only after 60 min of digestion. The surface of spheroplasts was studded with particles, about 25 to 30 nm in diameter. Many spheroplasts had a single large indentation, which may be in that part of the plasma membrane originally underlying the birth scar.