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L G Loginova

Publications and source records attributed to L G Loginova.

At least 19 recordsLinked to original sources
PubMed1982

Comparison of growth rates of two clones of Bacillus subtilis, producer of alpha-amylase.

In a population of the productive Bacillus subtilis strain the production of alpha-amylase differentiates at the cell level. Individual cells in the population were analyzed and the production of isolates was tested. The mean specific activity of alpha-amylase in the productive group after the isolation was 5.0 U/mg dry substance and in the nonproductive group 1.5 U/mg dry substance. This ratio remained unchanged during long-term observations and after repeated transfers. In selected strains of both groups the specific growth rate was determined in a synthetic medium containing various amounts of casein hydrolyzate. The detected differences in the growth rate between the productive and the nonproductive clones are determined by amino acid concentration.

Amylases↗
PubMed1981

Transport properties of two extremely thermophilic species of Thermus.

Thermus flavus and T. ruber grew optimally at 75 and 60 degrees C, respectively, but transport of monosaccharides (D-quinovose) and amino acids (2-aminoisobutyric acid) had optima about 20 degree C lower. Both transports were active, inhibited by 2,4-dinitrophenol but hardly at all by uranyl(2+) ions. Several transport systems are apparently involved with each class of compounds. Preincubation with glucose curtailed subsequent transport severely. Practical cessation of transport below 35 degrees C may be associated with the rather uniform composition of membrane lipids where iso- and anteiso-C15 and C17 acids are practically the only components.

Amino Acids↗
PubMed1976

Properties of proteolytic enzymes isolated from a thermophilic strain of Micromonospora vulgaris 42.

Two proteolytic enzymes, protease A and protease B, were isolated in homogeneous state from the cultural broth of the thermophilic actinomycete Micromonospora vulgaris 42. Their physicochemical properties were studied, i.e., molecular weight (50 000 for protease A and 30 000 for protease B), amino acid composition, N-terminal amino acids (phenylalanine for protease A and alanine for protease B). The specificity of the action of these enzymes was assayed by splitting the B chain of oxidized insulin. Both enzymes are neutral proteases of the thermolysine type.

Alanine↗
PubMedDate not supplied

[Production of protease during continuous cultivation of the thermophilic bacterium Bacillus brevis].

Conditions for continuous cultivation of the thermophilic strain of Bacillus brevis prodlcing protease are substantiated. The culture was cultivated in order to obtain proteolytic enzymes taking into consideration data concerning kinetics of the bacterial growth and enzyme synthesis, as well as results of studying accumulation of the pool of mRNA specific of protease synthesis, The rates of dilution and flow (approximately 0.4 hr-1) have been found which provide a high specific productivity of the culture.

Bacillus↗
PubMedDate not supplied

[Localization of cellulase in the Aspergillus terreus mycelial cells].

Localization of cellulase was studied in the cells of Aspergillus terreus 17P, a thermotolerant fungus. The activity of Cx-enzyme was found in the supernatant and to be of a protein nature, as was established by means of differential centrifugation of a homogenate of the mycelium cells. Ultrathin sections of the mycelium were fixed according to Somogi and studied by electron microscopy. The cellulase was found to be located on the surface of the cell wall to which it was bound but not very firmly, and was therefore detected in the supernatant.

Aspergillus↗
PubMedDate not supplied

[Thermophilic bacteria from hot springs of Kamchatka].

Spore-forming bacteria with the optimum growth temperature from 40 to 65 degrees C were isolated from hot springs of Kamchatka with the temperature 50-93 degrees C and pH 6.3-7.3: Bacillus stearothermophilus, B. brevis, B. subtilis, B. cereus, B. megaterium, and B. licheniformis. The bacterial have a high biochemical activity and play therefore an important role in decomposition of organic substances.

Amylases↗
PubMedDate not supplied

[Biosynthesis of cellulolytic enzymes and xylanase during submerged cultivation of the fungus Aspergillus terreus 17P].

The fungus Aspergillus terreus 17P--producer of cellulolytic enzymes--was cultivated in the Biotec 10 l fermenter on the medium containing minced and heated (at 200 degrees) wheat straw aerated with a different rate. At the mixing rate of 350 rpm and aeration rate of 0.7 r/rpm on the fourth day the culture liquid was obtained whose filtrate contained an active complex of cellulolytic enzymes and xylanase: CI--3.4; APB--1.1, Cx--35.7, cellobiase--0.23, xylanase--73.8 units/ml. The fractionation of the culture liquid filtrate with ammonium sulphate showed that the fraction precipitated at an interval of saturation of 0.3--0.7 contained the largest portion of cellulolytic enzymes and xylanase. The isolated enzymic preparations had a cellulolytic and xylanase activity and contained lipase, pectinase, laminarinase. They also contained low quantities of amylase, protease, beta-1,4- and beta-1,6-glucanase. Enzymic hylrolysis by the Asp. terreus 17P preparation of straw yielded glucose and xylose, of cotton, Na-KMC, cellobiose--glucose, Xylane hydrolyzate contained xylose and arabinose.

Amylases↗
PubMedDate not supplied

[Ecology of the obligate thermophilic bacteria].

The obligate thermophilic non-sporeforming bacterium Thermus ruber, isolated from the thermal springs of Kamchatka at temperatures of 60 to 90 degrees C (Loginova et al.,1974), has a high lytic activity towards the living and dead cells of Escherichia coli and Micrococcus lysodeikticus.

Bacteria↗
PubMedDate not supplied

[Regularities in the synthesis of neutral protease from Bacillus subtilis].

Experiments were carried out to study the formation of extracellular protease by the suspension from Bacillus subtilis str. 103 washed cells selected at the growth stages characterized by the highest rate of the enzyme synthesis (after 12 and 35 hours). In relation to the protein and RNA synthesis as measured by 14C-valine and 14C-uracyl the cells of that age showed a high metabolic activity. The enzyme synthesis by the cells of the log-phase was inhibited completely with chloramphenicol and by the cells of the stationary phase--almost completely. The experiments demonstrated the protease synthesis insensitive to riphampycin for a long time. This may be indicative of a certain pool of long-lived mRNA responsible for the biosynthesis.

Bacillus subtilis↗
PubMedDate not supplied

[Thermus ruber obligate thermophilic bacteria in the thermal springs of Kamchatka].

The new species of the obligate-thermophilic bacterium Thermus ruber is widely distributed in hot springs of Kamchatka with the temperature of water from 57 to 90 degrees C. The bacterium does not oxidize sulphur. It contains a red carotenoid pigment similar to neuro-sporaxanthine and retrodehydro-gamma-carotene.

Carotenoids↗
PubMedDate not supplied

[New species of thermophilic bacilli--Bacillus thermocatenulatus nov. sp].

Detailed study of the obligate-thermophilic aerobic spore-forming bacterium, indentified earlier as Bacillus megaterium, allowed to describe it as a new species--Bacillus thermocatenulatus nov. sp. This organism is characterized by a high content of GC in DNA (69 mole percent).

Bacillus↗
PubMedDate not supplied

[Several cytologic features of the thermophilic bacteria Thermus flavus and Thermus ruber].

The extreme thermophilic bacterium Thermus flavus 71 and the obligate thermophilic bacterium Thermus ruber 40 have been isolated from hot springs of Kamchatka and Tadjikistan, and their fine structure has been studied. This cells are similar in structure to gram-negative bacteria, they do not form spores or flagella, and their cell walls and cytoplasmic membrane are clearly visible under the electron microscope since the cells of T . flavus contain a yellow carotenoid pigment and the cells of T. rubber contain a bright-red carotenoid pigment. The Thermus genus is characterized by a wavy structure of the outer layer of the cell wall caused by numerous invaginations which ensure a close contact between the outer and inner layers of the cell wall.

Bacteria↗
PubMedDate not supplied

[Acidophilic obligate thermophilic bacteria, Bacillus acidocal-darius, isolated from the hot springs and soil of Kunashir Island].

Obligate thermophilic acidophilic cultures of Bacillus acidocaldarius were isolated from hot springs and soil of the Kunashir Island (the Kuril Islands) and Southern Sakhalin; their optimum temperature of growth is 65 degrees C and pH is 3.3--4.0. It has been shown for the first time that these organisms can be isolated from springs with either acidic or neutral and weakly alkaline pH values.

Bacillus↗