CATALASE ACTIVITY OF TWO STREPTOCOCCUS FAECALIS STRAINS AND ITS ENHANCEMENT BY AEROBIOSIS AND ADDED CATIONS

Proton NMR Study of Oxo-Bridged Dimanganese(III) Complexes: Solution State Structures and an Isotropic Shift/Magnetic Exchange Correlation

The (1)H NMR spectra of a series of manganese-oxo aggregates have been examined, and a characteristic signature was found for each complex. For the dimanganese(III,III) complexes [Mn(2)O(OAc)(2)(HB(pz)(3))(2)], [Mn(2)O(OAc)(2)(tacn)(2)](2+), [Mn(2)O(OAc)(2)(H(2)O)(2)(bpy)(2)](2+), and [Mn(2)O(OAc)(2)(bpta)(2)](2+) (HB(pz)(3) = hydrotris(pyrazol-1-yl)borate; tacn = 1,4,7-triazacyclononane; bpy = 2,2'-bipyridine, and bpta = N,N-bis(2-pyridylmethyl)-tert-butylamine), the (1)H NMR spectra reveal a resonance associated with acetate, found downfield between 58 and 80 ppm, and a generally well resolved set of terminal ligand resonances which can be divided into two classes: those resonances associated with pyridyl or pyrazolyl ring protons and those of methylene groups. A number of the pyridine ring resonances have been unambiguously assigned by the examination of methyl-substituted derivatives. Data for these derivatives also support a coordination geometry-dependent pathway for spin delocalization. Moreover, interpretation of the (1)H NMR spectra leads to the conclusion that the solution-state structures of all members of the series are the same as the reported solid-state structures. A strong linear correlation between the magnetic coupling constant (J) and the isotropic shift of the acetate resonance was observed within this series of {Mn(2)O(OAc)(2)}(2+) core complexes. Furthermore, comparisons of the acetate proton isotropic shift ratio (DeltaH(Mn)/DeltaH(Fe)) to the ratio of the squared effective magnetic moments &mgr;(eff)(2)(Mn)/ &mgr;(eff)(2)(Fe) for complexes with the {M(2)O(OAc)(2)}(2+) core (where M = Mn(3+) or Fe(3+)) revealed excellent agreement (within 10%) between these two quantities.

Inactivation and reactivation of manganese catalase: oxidation-state assignments using X-ray absorption spectroscopy

The oxidation states of the Mn atoms in three derivatives of Mn catalase have been characterized using a combination of X-ray absorption near-edge structure (XANES) and EPR spectroscopies. The as-isolated enzyme has an average oxidation state of Mn(III) and contains a Mn(III) form, together with a reduced Mn(II) form and a variable amount (10-25%) of a Mn(III)/Mn(IV) mixed-valence derivative. Treatment with NH2OH rapidly reduces the majority of the enzyme to a Mn(II) derivative with no loss of activity. Inactivation by treatment with NH2OH + H2O2 converts all of the enzyme to a mixed-valence Mn(III)/Mn(IV) form. The inactive, mixed-valence derivative can be completely reactivated by long-term (greater than 1 h) anaerobic incubation with NH2OH, giving a reduced Mn(II)/Mn(II) derivative. These data suggest a catalytic model in which the enzyme cycles between a reduced Mn(II)/Mn(II) state and an oxidized Mn(III)/Mn(III) state.

Synthesis of catalase by "Streptococcus faecalis subsp. zymogenes"

"Streptococcus faecalis subsp. zymogenes" was grown aerobically and anaerobically with glycerol as the source of carbon, and in the presence and absence of haematin. Catalase activity was found only during aerobic growth in the presence of haematin. The rate of appearance of catalase activity was measured on (a) addition of haematin to haematin-less aerobic cultures, and (b) aeration of haematin-containing anaerobic cultures in the presence or absence of chloramphenicol. These experiments suggested that apocatalase synthesis was induced by aeration and was not dependent on the presence of haematin in the growth medium. The binding of haem to apocatalase was oxygen dependent.

Functional significance of manganese catalase in Lactobacillus plantarum

A strain of Lactobacillus plantarum which was unable to produce manganese (Mn)catalase (ATCC 8014) grew somewhat more rapidly and to a slightly higher plateau density than did an Mn catalase-positive strain (ATCC 14421), and this was the case during aerobic or anaerobic growth. However, when maintenance of viability was measured during the stationary phase of the growth cycle, the advantage provided by Mn catalase was obvious. Thus, the viability of ATCC 14431 was undiminished over 21 h of aerobic incubation, during the stationary phase, whereas that of ATCC 8014 decreased by seven orders of magnitude. Addition of catalase to the medium or growth in the presence of hemin, which allows catalase synthesis, protected ATCC 8014 against this loss of viability. Suppression of Mn catalase within ATCC 14431 by treatment with NH2OH caused the cells to lose viability when exposed to 4 mM H2O2.

Inducible catalase in Pseudomonas fluorescens

The catalase activity of a non-proliferating suspension of Pseudomonas fluorescens doubled after six hours incubation in a 50 mM phosphate buffer medium (pH 7.3). The same effect was observed in a peptone medium. The increased activity was due to induced enzyme synthesis, and not to activation of preexisting catalase. Induced catalase was separated by electrophoresis from deuterium labelled constitutive catalase. The enzyme was also induced under anaerobic conditions in phosphate buffer or in culture when nitrate was supplied as an electron acceptor. Induction was considerably increased by the addition of various nucleotides and amino acids to the incubation medium.

Factors affecting catalase level and sensitivity to hydrogen peroxide in Escherichia coli

Composition of the culture medium, growth phase, and temperature play important roles in the sensitivity of Escherichia coli to H2O2. The medium and growth phase affected the sensitivity of the cells to H2O2 by modifying the amount of catalase synthesized by them, whereas the effect of temperature was due to the thermolability of the enzyme. Since catalase is unstable in the presence of its substrate, the correlation between the catalase level in the cells and their sensitivity to H2O2 could be observed only when the H2O2 concentration was not excessive in proportion to the amount of catalase.

Oxygen metabolism of catalase-negative and catalase-positive strains of Lactobacillus plantarum

Two catalase-negative strains of Lactobacillus plantarum and a strain producing the atypical, nonheme catalase were studied to determine if the ability to produce the atypical catalase conferred any growth advantage upon the producing strain. Both catalase-negative strains grew more rapidly than the catalase-positive strain under aerobic or anaerobic conditions in a glucose-containing, complex medium. Upon exhaustion of glucose from the medium, all three strains continued growth under aerobic but not under anaerobic conditions. The continued aerobic growth was accompanied by production of acetic acid in addition to the lactic acid produced during growth on glucose. Oxygen was taken up by exponential phase-cell suspensions grown on glucose when glucose or glycerol were used as substrates. Cells harvested from glucose-exhausted medium oxidized glucose, glycerol, and pyruvate. Oxygen utilization by a catalase-negative strain increased as did the specific activity of reduced nicotinamide adenine dinucleotide peroxidase during late growth in the glucose-exhausted medium. The catalase-positive strain and the catalase-negative strain tested both possessed low but readily detectable levels of superoxide dismutase throughout growth. The growth responses are discussed in terms of the presence of enzymes which would allow the cells to remove potentially damaging reduction products of O2.

Biological Response of Lactic Streptococci and Lactobacilli to Catalase

Addition of catalase to milk cultures of lactic streptococci resulted in increased rates of acid production, although it had no effect on cultures of lactobacilli. Milk cultures of both streptococci and lactobacilli produced detectable amounts of peroxide, which reached a maximum level in the early period of acid production followed by a drastic decrease as the acid production increased. Pyruvate and reduced glutathione decreased the amount of peroxide formed, but had little effect on acid production by the streptococci. Ferrous sulfate prevented the accumulation of peroxide and stimulated the rate of acid production by the streptococci to a greater extent than did catalase.

Relation of catalase to substrate utilization by Mycoplasma pneumoniae

No catalase activity was detected in four strains of glucose-grown Mycoplasma pneumoniae at any time during the replication of the organism. Exogenous catalase dramatically increased the O(2) uptake with glycerol, presumably by releasing inhibition caused by hydrogen peroxide. The effect of added catalase on the O(2) uptake of washed organisms with glucose as substrate was moderate and variable in degree. The production of hydrogen peroxide was demonstrated by the quantitative enzymatic assay for inorganic peroxide and by the fact that added pyruvate, which is non-enzymatically oxidized by H(2)O(2) to acetic acid and CO(2) could mimic the action of catalase.

Distribution and Characteristics of the Catalases of Lactobacillaceae

Johnston , M. A. (Cornell University, Ithaca, N.Y.), and E. A. Delwiche . Distribution and characteristics of the catalases of Lactobacillaceae. J. Bacteriol. 90: 347–351. 1965.—Certain strains of lactobacilli and pediococci incorporated hematin during growth, with the concomitant formation of cyanide- and azide-sensitive catalase. Three of five strains of lactobacilli and five of 25 strains of pediococci were capable of this biosynthesis. The pediococci required the heme component of blood, whereas the lactobacilli could incorporate the heme component in the form of purified and solubilized hemin or from blood. In all cases where inhibitor-sensitive enzyme was produced, it was accompanied by the production of inhibitor-insensitive enzyme. In the absence of hematin, only insensitive enzyme was obtained. Two catalase-positive strains of Streptococcus faecalis were found incapable of the synthesis of a heme-type enzyme, as was one member of the genus Leuconostoc . Iron and manganese in the growth medium stimulated the production of the insensitive catalase, but significant quantities of these metals could not be found in a purified enzyme preparation obtained from Lactobacillus plantarum . Aeration had little or no effect on growth, but it consistently doubled the amount of cyanide- and azide-resistant catalase. By means of conventional enzyme fractionation techniques, it was possible to separate the two different enzymes present in the cell-free extract of a strain of Pediococcus homari which had been grown in the presence of blood.

Isolation and Characterization of the Cyanide-Resistant and Azide-Resistant Catalase of Lactobacillus plantarum

Johnston , M. A. (Cornell University, Ithaca, N.Y.), and E. A. Delwiche . Isolation and characterization of the cyanide-resistant and azide-resistant catalase of Lactobacillus plantarum . J. Bacteriol. 90: 352–356. 1965.— Lactobacillus plantarum T-1403-5 has been shown to possess a very active cyanide- and azide-resistant catalase. By means of fractional ammonium sulfate precipitation, removal of nucleic acids with protamine sulfate, adsorption on calcium phosphate gel, and p H gradient chromatography on diethylaminoethyl cellulose, the catalase “activity” was purified approximately 14-fold. The purified enzyme preparation was insensitive to the heme poisons cyanide and azide, the metal chelating agents ethylenediaminetetraacetate and o -phenanthroline, and the sulfhydryl binding agent p -chloromercuribenzoate. The purified enzyme moved at a uniform rate in the electrophoretic field (isoelectric point, p H 4.7). The ultraviolet-light absorption spectrum was negative for heme-iron components, and fluorescence measurements yielded negative results with regard to flavin components. Acriflavin and Atabrine had no effect on enzyme activity. The nonheme catalase displayed a much broader p H range of activity than the heme-iron catalase of a control culture of Escherichia coli and the azide-sensitive catalase developed by L. plantarum NZ48 when grown in the presence of preformed hematin. The nonheme catalase was more resistant to heat inactivation. No retention of the enzyme on a chromatographic column could be obtained with Sephadex 200, nor could the enzyme be separated from crystalline beef-liver catalase by the gel filtration technique. Sedimentation was obtained in a centrifugal field of 144,000 × g for 12 hr.