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.     

Ion Effects on Calcium Accumulation by Cardiac Sarcoplasmic Reticulum

The effects of monovalent cations on the active calcium-accumulating ability of cardiac sarcoplasmic reticulum were assessed. Grana prepared in an ion-free system accumulated calcium when ATP and Mg⁺⁺ were present. Sodium ion and to a lesser extent lithium but not K⁺ reduced the amount of calcium taken up. The reduction of calcium binding by Na⁺ is not due to inhibition of uptake but to a rapid release of the radiocalcium bound. The amount of calcium released by sodium does not appear to be enough to explain contraction on the basis of sodium influx into muscle, but may be significant in the regulation of tension.     

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.     

Measurement of PGE2 as the methyl oxime by radioimmunoassay using a novel iodinated label

A radioimmunoassay has been developed for prostaglandin E2 (PGE2) using methyl oxime (MOX) derivatisation and a novel 125Iodine radiolabel. PGE2-methyl oxime (PGE2-MOX) is coupled through an imide linkage to proline in a pro-gly-tyr or similar peptide rather than through the conventional amide linkage to histamine or tyrosine methyl ester. The main advantage of this method is that the imide linkage in the label does not resemble the amide link used in the original antigen and the conjugate is therefore readily displaced by the natural PGE2. This overcomes the traditional difficulty encountered in hapten RIAs where the antiserum has a higher affinity for the label than it has for the compound to be measured. The assay that has been developed using these modifications and a solid-phase second antibody separation step, is both sensitive (with a lower detection limit of 0.5 pg/tube), reliable and simple and has the advantage that methyl oximation of the sample protects the PGE from degrading prior to and during the assay.