This report describes a new group of anaerobic bacteria that degrade oxalic acid. The new genus and species, Oxalobacter formigenes, are inhabitants of the rumen and also of the large bowel of man and other animals where their actions in destruction of oxalic acid may be of considerable importance to the host. Isolates from the rumen of a sheep, the cecum of a pig, and from human feces were all similar Gram-negative, obligately anaerobic rods, but differences between isolates in cellular fatty acid composition and in serologic reaction were noted. Measurements made with type strain OxB indicated that 1 mol of protons was consumed per mol of oxalate degraded to produce approximately 1 mol of CO2 and 0.9 mol of formate. Substances that replaced oxalate as a growth substrate were not found.

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NOTES 491were found to be monomeric and both exhibited normal magnetic moments. The visible spectrum of the anhydrous material in carbon tetrachloride, Figure 1, shows a well-separated shoulder on the high-energy side of the visible band; the spectrum of the dihydrate in the same solvent shows a less pronounced shoulder much closer to the main band. Since a well-separated shoulder is present on the high-energy side of the main band in the spectra of all other 6-dicarbonyl complexes of copper(II), this shoulder probably results from further splitting of the d orbitals as the symmetry is decreased from octahedral to square-planar; such an assignment has been discussed for bis(acety1acetonato)copper(II).' The position of this band, nearer the main band, in the dihydrate spectrum is probably due to a less pronounced tetragonal distortion and, thus, suggests that the waters are coordinated to the copper to give a distorted octahedron.Magnetic circular dichroism (MCD) has been observed for solutions of K2PtC14 in dilute HC1 which provides information relevant to the assignment of energy levels of the square-planar PtC14-2 ion. The energy level scheme of this ion has recently been discussed on the basis of polarized single-crystal spectra recorded a t 15°K.2 The experimental arrangement for the determination of circular dichroism was described earlier.3 Modifications have included : (1) a 30-fold electrical expansion of the recorder scale which does not appreciably alter the signal-to-noise ratio, (2) the replacement of the Jouan monochromator by an Applied Physics Corp. Model 15 monochromator, (3) the use of a 500-w xenon arc light source, (4) a change of the crystal modulation frequency in the dichrograph from 60 to 82 cps, (5) the use of an electromagnet to provide a magnetic field of 12,000 gauss in which the light beam travels from the south toward the north pole. A clockwise rotation for an observation toward the light source is called positive. Under

Several years ago it was reported that poly-a,L-glutamic acid (PGA) would form complexes with several symmetrical dyes, among them acridine orange (A0).'v2 Although the dye binds to either the helical or random coil conformations in water solution, the very interesting observation was made that A 0 exhibits optical activity only when bound to helical polymer. Similar observations have been made with AO: DNA complexes3; only the native, helical DNA solutions yield optical activity in the absorption bands of the bound dye. Largely on the basis of these results, others4-6 have recently begun to infer that some type of helical order might well exist in various polysaccharides, such as heparin and chondroitin sulfate. These polymers also yield optically active complexes with a number of symmetrical dyes. We have been investigating the optical properties of the AO: PGA system in some detail, and wish to give a preliminary report, on the observation of an optically active complex between A 0 and PGA in the random coil pH region.A given A 0 : PGA complex solution can be conveniently described by specifying the total dye molarity [D], theratioof glutamyl residues to dye molecules, RID, and the usual solution parameters, pH, ionic strength, etc. Spectroscopic titrations of A 0 solutions with PGA reveal that, at R/D values greater than 5, essentially all the available dye has been bound to the PGA throughout the pH range reported here.7 No further changes in the dye absorption spectrum take place until an extreme excess of PGA is added (RID