[Peroxidase of propionic acid bacteria]. / Peroksidaza propionovokislykh bakterii.

The peroxidase activity was found in Propionibacterium shermanii. Methods were developed to isolate and purify the enzyme. It was shown to be a heme-containing protein, specific to H2O2, stable at 20 to 30 degrees C and exerting the optimal action at pH 6.8 to 7.0. The rate of the enzyme-catalysed reaction was studied as a function of the enzyme and substrate concentrations. The Km was determined for H2O2 and o-dianisidine.

[Propionic acid cocci and their taxonomic position]. / Propionovokislye kokki i ikh sistematicheskoe polozhenie.

In order to determine the taxonomic position of propionic cocci, the authors studied their morphological, cultural and biochemical properties, the fatty acid composition of cells, and established the degree of homology for the DNAs of cocci and classical propionic bacteria using the method of molecular hybridization. The cocci were found to have the activities of catalase and superoxide dismutase which were higher than in the studied propionic bacteria. The propionic cocci and propionic bacteria were shown to be similar in terms of their fatty acid composition and to contain the C15-saturated acid in the form of anteiso isomer as the main type of fatty acids. Their fatty acid composition was most similar to that of the species Propionibacterium jensenii (P. technicum). The propionic cocci and bacteria are related in the structure of their genomes, particularly, in the case of the bacterium P. jensenii (P. raffinosaceum)--49%. On the basis of studying the phenotypic characteristics, the fatty acid composition, the nucleotide composition of DNA, and the high degree of homology between the DNAs of the cocci and the bacterial species P. jensenii (P. raffinosaceum), the authors propose to assign the cocci to the genus Propionibacterium as a new species Propionibacterium coccoides.

[Intracellular localization, isolation and characteristics of superoxide dismutase from Propionibacterium globosum]. / Vnutrikletochnaia lokalizatsiia, vydelenie i kharakteristika superoksiddismutazy iz Propionibacterium globosum.

From Propionibacterium globosum, superoxide dismutase (superoxide: superoxide dismutase, EC 1.15.1.1) has been isolated. As shown by polyacrylamide gel electrophoresis in native and denaturation conditions, the enzyme is a homogeneous protein with a specific activity of 3300 units/mg. In native conditions the enzyme molecular mass is 45,000 as measured by gel-filtration, and 22,000 as determined by Na-dodecyl sulphate electrophoresis. The enzyme is thermostable with pH optimum at 6.1-7.5. It has been found that superoxide dismutase of P. globosum is a membrane-independent cytoplasmic protein.

[Superoxide dismutase, catalase and peroxidase of propionic acid bacteria]. / [Superoksiddismutaza, katalaza i peroksidaza propionovokislykh bakterii.

The respiration of different species of propionic acid bacteria was found to be resistant to the inhibiting action of cyanide. Propionibacterium globosum, P. globosum (emm), P. vannielii, P. shermanii, P. petersonii, P. pentosaceum and P. raffinosaceum were shown to contain superoxide dismutase, catalase and peroxidase. The highest activity of catalase and superoxide dismutase was found in P. globosum and P. vannielii, the lowest one in P. shermanii and P. raffinosaceum. Peroxidase was detected in propionic bacteria for the first time.

[n-Alkane oxidation by propionic acid bacteria]. / Okislenie n-alkanov propionovokislymi bakteriiami.

Propionic acid bacteria were found for the first time to be capable of oxidizing n-alkanes. The value of QO2 is higher on a mixture of n-alkanes (C12--C20) than on individual hydrocarbons whose availability is determined by the length of a hydrocarbon chain: C15 and C16-alkanes are oxidized best of all; C14, C13 and C12-alkanes are oxidized at a lower rate; and alkanes whose chain comprises less than ten carbon atoms are not oxidized at all. Hexadecane is oxidized to CO2, cetyl alcohol and palmitic acid being intermediates; this suggests the existence of the monoterminal pathway for oxidation of n-alkanes in propionic acid bacteria.