Streptococcus faecium var. casselifavus, nov. var

Streptococcus faecium var. casseliflavus is a gram-positive, spherical cell. The cells occur chiefly as pairs within chains and elongate to ogive-shaped cells during growth. Growth is good on 5% bile salts-agar and in broth at 10 C, and in broth adjusted to pH 9.6 or containing 6.5% NaCl, but many strains fail to grow at 45 C. Litmus is reduced rapidly prior to formation of an acid curd. Few strains release ammonia from arginine or serine. The organism is not proteolytic and does not produce H(2)S or acetylmethylcarbinol, reduce nitrate, decarboxylate tyrosine, or produce slime on sucrose-agar. Most strains survive heating to 60 C for 30 min. It produces gray colonies on potassium tellurite agar, reduces 2,3,5-triphenyltetrazolium-HCl to a pink color, and ferments cellobiose, dextrin, maltose, mannose, and sorbitol, thus resembling S. faecalis. Like S. faecium, it produces peroxidase but not catalase on heated blood media, dissimilates malate, and ferments arabinose, melibiose, and salicin, but not melezitose. Like both species, it ferments dextrose, galactose, lactose, mannitol, sucrose, trehalose, and citrate. Properties peculiar to the variant include the high pH limiting initiation and termination of growth; the fermentation of alpha-methyl-d-glucoside, raffinose, and xylose; motility; and growth without blue button formation in ethyl violet broth. The water-soluble, pale lemon-yellow pigment is released into the aqueous phase only after the cell envelope is altered by fat solvents. The bacterium thrives as an epiphyte on plants.     

Selective Inhibition of Reovirus Ribonucleic Acid Synthesis by Cycloheximide

Cycloheximide, at a concentration of 10 mug/ml, rapidly blocked protein synthesis in L cells infected with reovirus. When the drug was added before 5 hr postinfection, synthesis of both single- and double-stranded varieties of virus-specific ribonucleic acid (RNA), which normally commences between 6 and 7 hr after infection, was blocked. When the cycloheximide was added at 9 hr after infection, uptake of uridine-H(3) into RNA, for the succeeding 6 hr at least, was similar to that of an infected culture without the drug. This latter uptake of uridine-H(3) in the presence of cycloheximide was largely into single-stranded RNA, since double-stranded RNA synthesis was rapidly and markedly inhibited by the cycloheximide. Single-stranded RNA formed in the presence of cycloheximide was found not to be a precursor of viral progeny, double-stranded RNA. Synthesis of double-stranded RNA in the infected cell probably requires prior synthesis of a new protein, which has a rapid rate of turnover. The possibility that formation of single-stranded RNA is preceded by synthesis of a second new protein is discussed.     

Extracellular polysaccharides of the genusRhizobium

This paper reports an investigation of the extracellular polysaccharides produced by 26 strains ofRhizobium andAgrobacterium. Strains ofRhizobium leguminosarum andR. phaseoli produced a water-soluble polysaccharide containing glucose, glucuronic acid and 4-0-methylglucuronic acid. These substances were also identified in the polysaccharide of a single strain fromLotus uliginosus. Glucose was the only detectable component in the polysaccharide produced by strains ofAgrobacterium radiobacter andA. tumefaciens. The polysaccharides obtained from slow-growing rhizobia were not freely water-soluble. Glucose, mannose, rhamnose, galactose and 4-0-methylglucuronic acid were identified as components of this extracellular material.These results are related to previous studies on rhizobial taxonomy and to the infection process in legumes.     

A computer programme for the calculation of the results of amino acid analysis

1. An ALGOL computer programme is presented for the calculation of the results of amino acid analysis. 2. The suggestion is made that a similar approach could be made to other tedious and repetitive biochemical calculations.