Nucleotide composition of nucleic acids of fungi. II. Deoxyribonucleic acids

Storck, Roger (The University of Texas, Austin). Nucleotide composition of nucleic acids from fungi. II. Deoxyribonucleic acids. J. Bacteriol. 91:227-230. 1966.-The nucleotide composition of the deoxyribonucleic acids (DNA) present in extracts of 30 species of fungi was determined. The results were analyzed, together with those in the literature. It was found that the content, in moles per cent of guanine plus cytosine (GC content), varied from 38 to 63% in a distribution composed of 9 species of zygomycetes, 14 of ascomycetes, and 9 each of deuteromycetes and basidiomycetes. The GC content ranges were: 38 to 48% for the zygomycetes, 38 to 54% for the ascomycetes, 47 to 62% for the deuteromycetes, and 44 to 63% for the basidiomycetes. The GC content ranged from 38 to 40% for four Mucor species. The base composition of fungal DNA appears, therefore, to have a taxonomic and phylogenetic significance.     

Effect of mineral acids on iron bacteria.

The oxidative ability of Thiobacillus ferroxidans in the presence of different concentrations of H2SO4, HC1, HNO3, and their mixtures was investigated. Bacteriological oxidation of FeSO4 is expressed as a function of time and acid concentration. For each acid and for their mixtures lethal concentrations for T. ferroxidans were found experimentally. On the basis of the lethal concentration for each acid separately the lethal concentrations of their mixtures were computed and it was found that they are in good agreement with the experimental data.     

Nucleotide composition of nucleic acids of fungi. I. Ribonucleic acids

Storck, Roger (The University of Texas, Austin). Nucleotide composition of nucleic acids from fungi. I. Ribonucleic acids. J. Bacteriol. 90:1260-1264. 1965.-The nucleotide composition of the ribonucleic acids (RNA) present in extracts of 26 species of fungi was determined. The results were analyzed, together with those in the literature. It was found that the content in moles per cent of guanine plus cytosine (GC content) varied from 44.1 to 60.5 in a distribution composed of 8 species of zygomycetes, 10 of ascomycetes, 11 of deuteromycetes, and 8 of basidiomycetes. The GC-content range and average were, respectively, 44.1 to 49.3 and 46.4 for the zygomycetes, 47.4 to 54.4 and 50.2 for the ascomycetes, 48.2 to 54.5 and 51.6 for the deuteromycetes, and 50.4 to 60.5 and 52.4 for the basidiomycetes. The GC content averaged 45.6 and ranged from 44.1 to 46.3 for four Mucor species. In addition, GC contents significantly lower than 50 were also encountered in some species of Hemiascomycetidae, suggesting that AT type RNA is not uncommon in fungi. It was proposed that the base composition of fungal RNA might have a taxonomic and phylogenetic significance.     

Effects of amino acids on sister-chromatid exchanges.

The effects of 10 amino acids on sister-chromatid exchange (SCE) frequency in human peripheral blood lymphocytes (PBL) and six amino acids on the SCE frequency in root tip cells of Hordeum vulgare were studied. Alanine (Ala), glycine (Gly), phenylalanine (Phe), valine (Val), histidine (His) and serine (Ser) induced a significant increase in SCE in PBL but threonine (Thr), isoleucine (Ile), lysine (Lys) and arginine (Arg) did not. Ala, Gly, Thr, Ile and Val induced a significant increase in SCE in root tip cells of Hordeum vulgare but Lys did not. The effect of Lys and bromodeoxyuridine (BrdU) on SCE levels in PBL and the interaction between them were also studied. The results show that Lys can inhibit the SCE induced by BrdU.     

Interaction of nucleic acids. VI. Interaction of purine with nucleic acids

The interaction of purine with DNA, tRNA, poly A, poly C, and poly A. poly U complex was investigated. In the presence of purine, the nucleic acids in coil form (such as denatured DNA, poly A and poly C in neutral solutions, or tRNA) have lower optical rotations. In addition, hydrodynamic studies indicate that in purine solutions the denatured DNA has a higher viscosity and a decreased sedimentation coefficient. These findings indicate that through interaction with purine, the bases along the poly-nucleotide chain are unstacked and are separated farther from each other, resulting in increased assymmetry (and possibly volume) of the whole polymer. Thus, the de-naturation effect of purine reported previously can be explained by this preferential interaction of purine with the bases of nucleic acids in coil form through a hydrophobic-costacking mechanism. Results from studies on optical rotation and helix-coil transition show that the interaction of purine is greater with poly A than with poly C. The influence of temperature, Mg⁺⁺ concentration, ionic strength, and purine concentration on the effect of purine on nucleic acid conformation has also been investigated. In all these situations the unraveling of nucleic acid conformation occurs at much lower temperatures (20–40°C lower) in the presence of purine (0.2–0.6M).     

Microbial desulfonation of substituted naphthalenesulfonic acids and benzenesulfonic acids.

Sulfur-limited batch enrichment cultures containing one of nine multisubstituted naphthalenesulfonates and an inoculum from sewage yielded several taxa of bacteria which could quantitatively utilize 19 sulfonated aromatic compounds as the sole sulfur source for growth. Growth yields were about 4 kg of protein per mol of sulfur. Specific degradation rates were about 4 to 14 mu kat/kg of protein. A Pseudomonas sp., an Arthrobacter sp., and an unidentified bacterium were examined. Each desulfonated at least 16 aromatic compounds, none of which served as a carbon source. Pseudomonas sp. strain S-313 converted 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 5-amino-1-naphthalenesulfonic acid, benzenesulfonic acid, and 3-aminobenzenesulfonic acid to 1-naphthol, 2-naphthol, 5-amino-1-naphthol, phenol, and 3-aminophenol, respectively. Experiments with 18O2 showed that the hydroxyl group was derived from molecular oxygen.     

Synthesis of teichoic acids. VII. Synthesis of teichoic acids during spore germination

The synthesis of teichoic acids has been examined during germination in Bacillus licheniformis ATCC 9945 and in B. subtilis W-23. Teichoic acids are absent from the spores of both organisms. B. licheniformis spores lack the enzymes responsible for teichoic acid synthesis. The appearance of these enzymes during germination is correlated with the appearance of teichoic acids in the cell. The appearance of teichoic acid-synthesizing enzymes and of teichoic acids in the cell are inhibited by the addition of chloramphenicol to the germination medium. In B. subtilis W-23 the situation is similar for the synthesis of polyribitolphosphate. The synthesis of glucosyl polyribitolphosphate is only partially inhibited by chloramphenicol, puromycin, and penicillin, and uridine diphosphate-d-glucose polyribitol-phosphate glucosyl transferase can be demonstrated in spores. The possible implications of some of these observations are discussed.     

Effects of free fatty acids on fibrinolytic activity.

A novel method for the estimation of fibrinolytic activity is proposed. In this method, a fibrin clot suspension is used as a substrate (fibrin is known to be a physiological substrate of plasmin). The fibrin clot suspension was prepared by homogenization of human fibrin clots. With this method, we found that free fatty acids inhibited the plasmin activity, and long-chain, unsaturated free fatty acids had a particularly strong inhibitory action on plasmin. As regards the mechanism of the inhibitory action, free fatty acids may not inhibit complex formation between plasmin and fibirin, but may make it impossible for plasmin to act on fibrin due to deformation of the surface of the fibrin clot.     

Inhibitory effect of hydroxycinnamic acids on Dekkera spp.

Simple phenolic components of wine, hydroxycinnamic acids (HCAs) are known to have antimicrobial properties. This study sought to determine the potential of ferulic acid as an antifungal agent for the control of Dekkera. Growth was inhibited by all HCAs examined in this study, with ferulic acid being the most potent at all concentrations. In the presence of ethanol, the inhibitory effects of ferulic acid were amplified. Scanning electron microscopy images reveal cellular damage upon exposure to ferulic acid. Thus, manipulation of ferulic acid concentrations could be of industrial significance for control of Dekkera and may be the basis for differences in susceptibility of wines to Dekkera spoilage.     

Chemical properties of bile acids. IV. Acidity constants of glycine-conjugated bile acids

The dissociation constants for the carboxyl group of a series of glycine (N-acyl)-conjugated and unconjugated bile acids were determined by potentiometric titration using dimethylsulfoxide-water and methanol-water mixtures of varying proportions. The pKa values in water were calculated by extrapolating the experimental values determined in different mole fractions of the organic solvent mixtures. The following values were obtained: 3.9 +/- 0.1 for glycine-conjugated bile acids and 5.0 +/- 0.1 for unconjugated bile acids, as general pKa values for the two classes of bile acids, respectively. The amidation of bile acids with glycine lowers the pKa value because of the proximity of the amide bond to the terminal carboxyl group. Bile acid dissociation constants are independent of the substituents in the steroid nucleus, since inductive effects of the hydroxyl groups on the steroid nucleus are too distant from the acidic group at the end of the side chain to influence its ionization.