[Isolation and characterization of lipase from Geotrichum asteroides FKM F-144]. / Vydelenie i nekotorye svoistva lipazy Geotrichum asteroides VKM F-144.

By gel chromatography on Sephadex G-75 it has been demonstrated that the culture fluid of Geotrichum asteroides VKM F-144 contains two lipolytic components, one of which, lipase 1, eluates in the free volume of the column, whereas the second component, lipase 2, eluates in the volume close to that of the egg albumin yield. The paper describes a method for lipase 2 preparation consisting of precipitation of accompanying compounds at pH 4.2, depigmentation of the supernatant on the resin PAP in the Cl-form, selective sorption of lipase on the cation exchange resin CMC and further purification of the eluate gel chromatography and Sephadex G-100 rechromatography. The molecular weight of the lipase is estimated to be 45,000 and the isoelectric point to correspond to pH 4.3. pH optimum of action of the purified enzyme, areas of its pH- and thermostability have been determined.

[Synthesis and hydrolysis lipids in microorganisms (a review)]. / Sintez i gidroliz lipidov u mikroorganizmov (obzor).

The review presents current concepts of the synthesis and hydrolysis of phospholipids and triglycerides of microorganisms. The paper discusses differences in the synthesis of phospholipids in micro- and macroorganisms as well as properties an reversal of action of lipases (triglyceride hydrolases) in microorganisms.

[Localization of the extracellular lipase in Candida paralipolytica yeasts]. / Lokalizatsiia vnekletochnoi lipazy u drozhzhei Candida paralipolytica.

The localization of lipase in the cells of Candida paralipolytica was studied for the first time by the techniques of electron cytochemistry and immunocytochemistry. Lipase is formed at the outer surface of the cytoplasmic membrane and often is confined to its invaginations. The reaction products were detected in individual parts of the periplasmic space, in the cell wall, and in its exofibrillar components. Apparently, lipase is formed on the ribosomal-membrane complex. The above pattern is observed only in the cells with a high lipase activity, but not in the control. The two techniques gave similar results. A series of electronograms are presented.

Some properties of lipase from Geotrichum asteroides.

The optimal conditions for the manifestation of the lipase activity of an enzyme preparation from the culture liquid of the fungus Geotrichum asteroides were determined. It was found that the rate of hydrolysis depends on the substrate concentration, the enzyme concentration, and the reaction time. The lipase from G. asteroids is rather stable--it loses practically no activity in a year at 4 degrees C. The temperature optimum of the enzyme preparation is 37 degrees. The lipase from G. asteroides is most active at pH 8.0; it retains its activity when kept for 3 h in a reaction medium with a pH from 3 to 10.

[Conditions of exolipase biosynthesis by the fungus Oospora fragrans]. / Usloviia biosinteza ekzolipazy gribom Oospora fragrans.

The fungal strain Oospora fragrans isolated from sunflower seeds had a high lipase activity, especially on the media containing soybean flour and various oils. The fungal lipase showed inductive characteristics, the best inducers being olive and soybean oils. The biosynthesis of lipase from O. fragrans occurred at the optimal temperature of 26-30 degrees C and strong aeration. Maximun of lipolytic activity did not coincide with maximum accumulation of biomass and developed at the log-phase of the fungal growth. With age the lipid content in the mycelium increased in parallel with the biomass accumulation. Mycelial lipids of O. fragrans contained nine fractions, among which fatty acids and triglycerides were in predominance. The study of properties of O. fragrans lipase showed a high pH value and thermal stability, the capacity to function at low temperatures, and activity towards many substrates. The enzyme readily hydrolyzed not only natural vegetable (olive, linseed and mustard) oils but also oils of microorganisms grown on petroleum hydrocarbons.

Substrate specificity of a lipase preparation from Geiotrichum asteroides as a function of the experimental conditions.

A lipase preparation obtained from the culture fluid of the fungus Geotrichum asteroides was shown to hydrolyze natural plant oils well. Tweens and triglycerides, both soluble in water and insoluble, containing saturated fatty acids (tripalmitic, tristearic, trimyristic and tributyric) are barely hydrolyzed. The nature of the emulsifier and the composition of the buffer used in the reaction mixture exert a great influence on the lipolytic activity of G. asteroides. The optimal temperature for the enzyme preparation with respect to all the oils studied was 37 degrees C.

[Lipolytic activity of microorganisms isolated from different sources]. / Lipoliticheskaia aktivnost' mikroorganizmov bydelennykh iz razlichnykh istochnikov.

From different natural sources (samples of raw and pasteurized milk, fresh and melted butter, cheese, industrial and nonindustrial sewage containing fats and surface active substances) 650 microorganisms were isolated. Measurements of their lipolytic activity on milk fat (20% cream), tristearin and olive oil indicated that 27 microorganisms had no lipolytic activity on either substrate. A hundred cultures showed the highest activity. Out of them 40 most active cultures belonging to different systematic groups (fungi, yeast, bacteria) were identified as representatives of certain genera or species. Lipolytic activity varied significantly in microorganisms belonging to the same species. The use of several substrates (cream, tristearin, olive oil) helped to discriminate microorganisms that preferentially hydrolyzed either substrate.

[Comparative study of the properties of lipase of microbial origin]. / Sravnitel'noe izuchenie svoistv lipaz mikrobnogo proiskhozhdeniia

A comparative study of properties of lipases of microbial origin has shown that the pH optimum of the enzymes from Geotrichum asteroides and Penicillium sp. is at pH 7.5 and 5.0, respectively. Lipase from Geotrichum asteroides appears more resistant to high temperatures and pH changes than the enzyme from Penicillium sp. Both enzymes split selectively vegetable oils, especially cotton and sunflower oils. Na cholate and deoxycholate at a concentration of 0.05-0.4% act as hydrolysis activators, particularly with respect to Geotrichum lipase. Na dehydrocholate does not show this effect.

[The effect of metal ions on the lipolytic activity of Mycobacterium rubrum and Actinomyces streptomycini]. / Vliianie ionov metallov na lipoliticheskuiu aktivnost' Mycobacterium rubrum i Actinomyces streptomycini

Hydrolysis of olive oil by intact cells of Mycobacterium rubrum 403 and "acetone" preparations of Actinomyces streptomycini 116 was found to be inhibited by the following ions: Ca2+, Mg2+, Mn2+, Ba2+, Co2+, Cd2+, Cu2+, Zn2+, Fe2+, Fe3+, Ni2+. Olive oil is hydrolyzed by the growing culture of Act. streptomycini 116 only in the presence of bivalent metal ions. The biosynthesis of lipase by Mycobatcerium rubrum 403 and Act. streptomycini 116 is increased twofold by magnesium ions. The biosynthesis of lipase by Act. stroptomycini 116 is stimulated also by calcium ions.

[Fatty acid makeup of the lipids in soil and epiphytic yeasts]. / Zhirnokislotnyi sostav lipidov pochvennykh i épifitnykh drozhzhei

The fatty acid composition of lipids was compared among yeast cultures belonging to the genera Rhodotorula, Lipomyces, and Cryptococcus. These lipids contain C10--C26 fatty acids, mainly with the even number of carbon atoms. Palmitic acid (C16 : 0) and oleic acid (C18 : 0) predominate. In the majority of the strains, the sum of unsaturated acids exceeds the sum of saturated acids. The content of unsaturated acids in the lipids of the epiphytic yeast Rhodotorula is higher than in the soil yeast Lipomyces. Besides C12--C18 acids, C22--C26 acids were identified by GLC at preset temperatures. Lignoceric acid (C24 : 0) was found for the first time in the cultures of Rhodotorula, Lipomyces, and Cryptococcus, and cerotinic acid (C16 : 0) was also detected in the Rhodotorula yeast. Fatty acids with a long chain are registered in the strains of Rhodotorula more often than in the strains of Lipomyces and Cryptococcus.

[Characteristics of a Mycobacterium mucosum culture oxidizing cholic acid]. / Nekotorye osobennosti kul'tury Mycobacterium mucosum, okisliaiushchei kholevuiu kislotu

Some physiologo-morphological and biochemical characteristics were studied with the culture of Mycobacterium mucosum 1210 which can assimilate cholic acid as a sole source of carbon. This culture is capable of spontaneous variability. Four variants of the culture were obtained which possessed different rates of the transformation of cholic acid. The variant which formed slimy colonies of pale-yellow colour was the most active. Some morphological modifications of the cells were investigated in the course of cultivation, such as the size, shape and formation of the capsules. Various growth media were tested, and the optimal values of pH were selected.