摘要:

AbstractThe oxidative ability ofThiobacillus ferrooxidansin the presence of different concentrations of H2SO4, HCl, HNO3, and their mixtures was investigated. Bacteriological oxidation of FeSO4is expressed as a function of time and acid concentration. For each acid and for their mixtures lethal concentrations forT. ferrooxidanswere 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.

ISSN:0044-2208    

DOI:10.1002/jobm.19750150502

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractKinetische Untersuchungen haben gezeigt, daß der Phage 187 irreversibel, der Phage 54 über‐wiegend irreversibel und der Phage 83A reversibel an ausgewählte Mureinpräparationen spezifisch gebunden wird. Es liegen Rezeptormechanisme

ISSN:0044-2208    

DOI:10.1002/jobm.19750150503

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe photochemical stability of anomalous nucleic acid bases of the azatype, 5‐azacytosine (I), 5‐azacytidine (II), 6‐azacytosine (III), 6‐azacytidine (IV), 6‐azathymine (V), 6‐azauracil (VI), and 8‐aza‐adenine (VII) to U. V. light of the wavelength 254 nm differs from the U. V. stability of the normal constituents. Changes of the U. V. inactivation ofEscherichia coliK12 C600,E. coliB,Bacillus cereus, as well asE. coliphages λ cb2and λ b2b5supplemented with azaderivatives prior to irradiation were investigated. It was found that I, II, III, IV, and VII are more, V and VI less sensitive to U. V. light compared with corresponding natural nucleic acid bases. Their changed U. V. sensitivities are reflected in the survival curves after U. V.‐irradiation in as far as azabases are incorporated into the nucleic acidsin vivo.This explains the increase in U. V. sensitivity ofE. coliK12 C600,E. coliB, andB. cereussupplemented with I, II, III, IV, and VII and the decrease in U. V. sensitivity ofStreptococcus faecalissupplemented with V (the latter information was taken from GÜNTHER and PRUSOFF 1967). The lack of any significant influence on inactivation curves ofE. coliK12 C600 by V and VI, and onE. coliphages λ cb2and λ c2b5by II, is discussed in terms of too small incorporation rates. No discrimination was put forward with respect to DNA

ISSN:0044-2208    

DOI:10.1002/jobm.19750150504

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractTwo unicellular algae, viz.,Anacystis nidulansandChlorella vulgaris, growing in polluted effluents, were isolated in unialgal and bacteria free culture. They were mutagenically exposed to ultraviolet radiation and variant strains endowed with differing capacities for growth and nutrient‐gleaning were successfully isolated as distinct clones on agar plates. One such clone each of the two species was tested further and found stable. While these variant strains grew more slowly than untreated controls, statistically significant differences with respect to phosphate and nitrate uptake were found between treated and control strains of the two specie

ISSN:0044-2208    

DOI:10.1002/jobm.19750150505

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe mouldAspergillus nigerwas grown in a carefully established culture medium containing one of the following test substrates: cyclopentanone, ‐hexanone, ‐heptanone, and their 2‐substituted methyl derivatives. Growth curves, glucose consumption curves and curves showing the course of the oxido‐reduction reaction ar

ISSN:0044-2208    

DOI:10.1002/jobm.19750150506

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractHigher concentrations of terrazol inhibit the growth of a large number of fungi, but oomycetes are most sensitive. At medium concentrations (ED50= 10 ppm) inMucor mucedoseveral alterations of ultrastructure are recognizable even after short incubation periods. Significant observations are vacuolization of the mitochondrial cristae, invagination of the cytoplasmic membrane, and thickening of the cell wall. Later on, numerous vacuoles in the cytoplasm are visible. Primary effects on the cell membrane (destructive effect), on O2‐consumption, on fermentation, or on nucleic acid synthesis could not be demonstrated. Lipid synthesis under the influence of terrazol showed characteristic changes. The synthesis of triglycerides and sterolesters was inhibited while the synthesis of free fatty acids and phospholipids was stimulated. Addition of lipids, vitamines, amino acids, or nucleic acids did not counteract the effect of terrazol. Further investigations are necessary to elucidate the primary mechanism of actio

ISSN:0044-2208    

DOI:10.1002/jobm.19750150507

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractProteus mirabilisstrain 1095/67 has been cultivated in surface culture on different minimal media, which were composed either of single amino acids or combinations of several amino acids without or with stepwise addition of other C‐sources up to the complete medium. We found a direct dependence of the formation of the various antigens (moving to the cathode, to the anode, or not moving) on the composition of the medium.Certain amino acids (Ala, Glu, Asp, Ser) elicit only parts of the antigenic spectrum formed in complete medium, but enrich special antigens. With only 2 amino acids (Ala and Glu) and the vitamins thiamine, pyridoxal, and niacine in the anorganic basic medium the complete antigenic spectrum can be formed. We have shown that the composition of the cell wall varies with the composition of the culture medium.In shaked cultures we found serine to be essential for the production of the antigen moving to the cathode and the thermolabile antigene moving to the anode (ATA), niacine to be of fundamental importance in the biosynthesis of all antigens. Already under very limited supply of nutrients ATA, common to all gram‐negative bacteria, is formed and, therefore, it seems to be a very basic cell wall compon

ISSN:0044-2208    

DOI:10.1002/jobm.19750150508

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe regulation of the synthesis of the enzyme urease (urea amido hydrolase E.C. 3.5.1.5.) inNeurospora crassawas investigated. The biosynthesis of urease is repressed by ammonium ions. Under ammonium excess conditions the specific activity of urease decreases from 0.980 to 0.180 μmoles NH3/min/mg protein.By addition of cycloheximide it was shown that ammonia influences the synthesis of this enzyme. Enzyme induction by the substrate could be excluded.Even under the conditions of highest repression a specific activity of urease of 0.180 μmoles NH3/min/mg protein was measured. Possible causes of this constitutive enzyme level are discusse

ISSN:0044-2208    

DOI:10.1002/jobm.19750150509

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19750150510

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19750150511

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY