[Consumption of volatile organic compounds by alcaliphilic microorganisms].

It has been shown that various microbial species used in bioreactors for purification of air from volatile organic compounds can grow at alkaline pH values consuming the xenobiotics as sole carbon sources. The alkali tolerance depends on the carbon source. The alkaline pH of the medium reduces the foreign microbial population restricting the potential of the bioreactor.

[Search for yeast producers of brassylic and sebacic fatty acids]. / Poisk drozhzhei-produtsentov brassilovoi n sebatsinovoi zhirnykh kislot.

Yeast cultures belonging to the genera Candida, Torulopsis, Saccharomyces, Debaryomyces, Hansenula, Pichia, and Yarrowia, capable of synthesizing brassylic and sebacic fatty acids, were screened. Overall, about 200 cultures grown in media containing decane or tridecane as a sole source of carbon were tested. On the medium with tridecane, yeasts synthesized insignificant amounts of brassylic acid. Sebacic acid was produced more intensively in the medium with n-decane. The culture Candida tropicalis, displaying the highest ability to synthesize sebacic acid, was selected.

[Analysis of kinetic parameters of gas phase bioreactors]. / Analiz kineticheskikh parametrov gazofaznykh bioreaktorov.

The dependence of toluene elimination capacity on its load was obtained in five small-scale reactors filled with glass beads carrying biocatalyst cells. With increase in operation time the calculated maximal elimination capacity was shown to increase along with biomass density in the biocatalyst bed. Fivefold increase in trickling intensity did not affect the reactor performance. A simplified mathematical model for evaluation of minimal required biocatalyst bed volume at certain loading was developed based on experimental dependence of elimination capacity vs. loading.

[Beta-galactosidase of the superthermophilic anaerobic bacteria Thermoanaerobium sp. 2905 and its immobilization]. / Beta-galaktozidaza supertermofil'noi anaérobnoi bakterii Thermoanaerobium sp. 2905 i ee immobilizatsiia.

The composition of nutrition medium for cultivating the extreme thermophilic anaerobe Thermoanaerobium sp. 2905 was optimized, which enabled the bacterial beta-galactosidase production to be substantially enhanced. Xylan and ammonium phosphate were selected as optimal carbon and nitrogen sources, respectively. The enzyme was purified fivefold by precipitation of the aqueous cell extract with alcohol (1:1, v/v), and crude preparation with a specific activity of 46 U per mg protein was obtained. Cells of the extreme thermophile were entrapped into natural or synthetic latex.

[Furane compounds formed upon heating highly-sugared fermented media]. / Furanovye soedineniia, obrazuiushchiesia pri nagrevanii vysokosakharistykh sbrozhennykh sred.

5-Methylfurfural diethyl acetal, 5-methylfuran acid ester, and 4-hydroxypentanoic acid ethyl ester were first identified in high-sacchariferous corn media subjected to alcoholic fermentation by Mucor X-I culture and in aged sweet wines by means of GLC, GLC-MS, and TLC, as well as by UV and IR spectroscopic examinations. These substances are products of enzymatic esterification of sugars followed by their dehydration by heat treatment or long seasoning of grape wines.

Structure and properties of a Cephalosporium acremonium alpha-galactosidase.

The amino acid and sugar composition of the enzyme protein, the effect of urea, sodium dodecyl sulphate and Concanavalin A on the purified alpha-galactosidase (EC 3.2.1.22) from the mold Cephalosporium acremonium has been studied. The results obtained by gas liquid chromatography indicated the presence of N-acetylglucosamine, mannose, galactose and N-acetylneuramic acid in the molar proportions 2:7:3:11. The presence of two types of Asn-linked oligosaccharide structures in the enzyme molecule is assumed. The alpha-galactosidase liberates alpha(1-3), alpha(1-4) and alpha(1-6)-linked D-galactose units from various synthetic and natural substrates which have been tested. The effects of pH, substrate concentration and temperature on the catalytic activity of the enzyme are described. The purified alpha-galactosidase also exhibited a lectin activity with an affinity towards glucose, and to some extent mannose.

Low-molecular-weight trypsin inhibitors of microbial origin.

Three hundred actinomyces cultures newly isolated from the soil of different regions of the Soviet Union were tested for their ability to produce inhibitors of trypsin-like proteases. Seven previously not known to produce trypsin inhibitors (Streptomyces bikiniensis 17-5, S. sporoclivatus 28-1, S. filamentosus 32-11, S. diastatochromogenes 20-4, S. lavendulae 29-4, S. violacens 52-8, and Streptoverticillium cinnamoneum 36-8) were found to possess high antitrypsin activity. The morphological and cultural properties of the strains and the dynamics of inhibitor production were investigated. S. bikiniensis 17-5 was studied in greatest detail. Its culture filtrate contained several inhibitors for trypsin and one for chymotrypsin. A mixture of oligopeptides with Mr of 300-500 was obtained by the described procedure which included the adsorption of the culture fluid filtrate on charcoal followed by ion-exchange chromatography on CM-cellulose. Four trypsin inhibitors (Sb-IT1, Sb-IT2, Sb-IT3, and Sb-IT4) were isolated from the mixture in a highly purified state by reversed-phase high-performance liquid chromatography. Sb-IT2 has been recognized as formylhistidylvaline with an Mr of 282. No trypsin inhibitor of this structure has been described previously.

[Actinomycetes producing trypsin inhibitors]. / Aktinomitsety, produtsiruiushchie ingibitory tripsina.

The ability to produce inhibitors of trypsin-like proteases was tested in 300 cultures of actinomycetes freshly isolated from different soils of the USSR. A high antitrypsin activity was found in seven cultures which had not been known before as those producing trypsin inhibitors: Streptomyces sporoclivatus 28 (1), S. lavendulae 29 (4), S. diastatochromogenes 20 (4), S. violascens 52 (8), S. bikiniensis 17 (5), S. filamentosus 32 (11), and Streptoverticillium cinnamoneum 86 (8). The morphological and cultural characteristics of the strains were studied as well as their production of trypsin inhibitors.

[Isolation and properties of an alpha-galactosidase preparation from Cephalosporium sp. 237]. / Poluchenie i svoistva preparata al'fa-galaktozidazy iz Cephalosporium sp. 237.

Different methods for preparing alpha-galactosidase from the culture fluid of the micromycete Cephalosporium sp. 237 were tested. They included precipitation with ethanol, isopropanol, and acetone. Precipitation with two volumes of acetone gave the best results with respect to specific activity (12 units) and yield of the enzyme (78%). Properties of alpha-galactosidase (optimum pH at 5.5, temperature optimum at 40 degrees C. thermolability, etc), when different substrates were used, were examined.

[Microbial alpha-galactosidase (a review)]. / al'fa-Galaktozidaza mikroorganizmov (obzor).

The review discusses properties, distribution and potential use of microbial alpha-galactosidase (alpha-D-galactoside galactohydrolase, EC 3.2.1.22), the enzyme catalyzing degradation of alpha-D-galactoside bonds. Recent years have witnessed many publications describing microbial alpha-galactosidase which, in contrast to the similar enzyme from higher plants, has been poorly studied. The microbial enzyme has certain specificities: a smaller substrate specificity, existence in one molecular form, etc. The present communication is an attempt to systematize the data about microbial alpha-galactosidase and to outline the most important investigations for the future.

[Amino acid composition and quaternary structure of glucosoisomerase (d-xylose-ketol-isomerase) from Actinomyces olivocinereus 154]. / Aminokislotnyi sostav i chetvertichnaia struktura gliukozoizomerazy (d-ksilozo-ketol-izomerazy) Actinomyces olivocinereus, shtamm 154.

The amino acid composition of glucosoisomerase from Actinomyces olivocinereus 154 was investigated. The content of dicarboxylic acids--aspartic and glutamic--was found to be greater than that of basic acids--lysine, arginine and histidine. Hydrophobic acids were also detected to occur on appreciable quantities. No cysteine was seen in the enzyme. The experimental data on the effect of sodium dodecyl sulfate and urea suggests that the enzyme has a quaternary structure consisting of four nonidentical subunits.

[Purification of glucosoisomerase from Lactobacillus brevis and its physico-chemical properties]. / Ochistka gliukozoizomerazy Lactobacillus brevis shtamm 74 i fiziko-khimicheskie svoistva fermenta.

Glucosoisomerase isolated from disrupted cells of Lactobacillus brevis 74 by extraction with K, Na phosphate buffer was purified by step-by-step fractionation with (NH4)2SO4 and DEAE-cellulose chromatography. The purified enzyme was examined by polyacrylamide gel electrophoresis and ultracentrifugation. The examination showed the enzyme to be homogeneous. The sedimentation constant of the enzyme was found to be 8.3 S. The molecular weight of the enzyme was estimated to be 200 000. The presence of the carbohydrate moiety in the enzyme was demonstrated by qualitative methods.

[Inhibition of glucose isomerase from Actinomyces olivocinereus 154 by polyols]. / Ingibirovanie gliukozoizomerazy iz Actinomyces olivocinerus 154 poliolami.

The inhibitory action of polyols, e. g. D-mannitol, D-glucitol, ribitol and xylitol, on the activity of glucose isomerase prepared from Actinomyces olivocinereus 154 was studied. All the polyols under study are purely reversible competitive inhibitors. The values of Ki for D-mannitol, D-sorbitol, D-arabitol, D-glucitol, ribitol and xylitol are 0.200, 0.140, 0.030, 0.024 and 0.020 M, respectively. The inhibition is to some extent decreased by increasing concentrations of the substrate and is completely abolished by increasing concentrations of Mg2+ and Co2+--up to 5.10(-2) and 5.10(-3) M, respectively.

[Conversion of D-glucose into D-fructose in a column reactor with immobilized glucose isomerase]. / Izomerizatsiia D-gliukozy v D-fruktozy v kolonochnom reaktore s immobilizovannoi gliukozoizomerazoi.

Conversion of D-glucose into D-fructose in a column reactor of a continuous type was studied using an immobilized enzyme, glucose isomerase from Actinomyces olivocinereus. The effective parameters of Km, Vmax, energy activation at various flow rates were calculated. During 32 days of continuous operation the enzyme activity fell down to 84% of the initial level. A system of recirculation was employed to use immobilized glucose isomerase with a low activity.

[Alpha-galactosidase producers among yeast cultures]. / Produtsenty al'fa-galaktozidazy spedi drozhzhevykh kul'tur.

The capacity for biosynthesis of alpha-galactosidase was examined in 89 yeast cultures belonging to 21 genera during submerged cultivation on a medium containing dry whey. This capacity was found only in one genus, namely Schwanniomyces. Optimal cultivation conditions were selected for the strain Schw. alluvius 1167 that showed the highest alpha-galactosidase activity. As a result, activity of alpha-galactosidase was increased 4.8 times as compared with the initial level.

[Highly purified glucosoisomerase from Actinomyces olivocinereus 154]. / Vysokoochishchennaia gliukozoizomeraza Actinomyces olivocinereus shtamm 154.

The paper presents a method for producing highly purified glucosoisomerase from Actinomyces olivocinereus 154. The scheme of purification includes enzyme extraction from dry biomass, acetone fractionation, ammonium sulfate precicipation, and Sephadex G-200 chromatography. The highly purified enzyme is homogeneous as shown by polyacryl amide gel electrophoresis, analytical ultracentrifugation, and gel filtration. The highly purified enzyme has been prepared in a crystalline form. The molecular weight of the enzyme has been estimated by sedimentation equilibrium to be 162 000 and by gel filtration to be 158 000. The sedimentation constant of glucosoisomerase has been found to be 8.52 S.

[Microorganisms that produce alpha-galactosidase, alpha-mannosidase, alpha-fucosidase and beta-acetylglucosaminidase]. / Mikroorganizmy, obrazuiushchie al'fa-galaktozidazu, al'fa-mannozidazu, al'fa-fukozidazue i beta-atsetilgliukozaminidazu.

The capacity to synthesize alpha-D-galactosidase (EC 3.2.1.22), alpha-D-mannosidase (EC 3.2.1.24), alpha-L-fucosidase (EC 3.2.1.51) and beta-D-acetylglucose aminidase (EC 3.2.1.30) was tested among 100 different cultures of soil microscopic fungi and actinomycetes. Two genera of micromycetes, viz. Scopulariopsis and Aposphaeria, which had not been known as producing alpha-D-galactosidase, were found, as well as several new species of the genus Penicillium: Pen. canescens, Pen. claviforme, Pen. cyclopium, Pen. daleae, Pen. frequentans, Pen. piscarum, Pen. simplicissimu, Pen. thomii.

[Glucose-isomerizing enzyme from Actinomyces olivocinereus and its immobilization on aminosilochrome]. / Gliukozonzomeraza iz Actinomyces olivocinereus 154 i ee immobilizatsiia na aminirovannom silokhrome.

Glucose-isomerizing enzyme was isolated from the culture of Actinomyces olivocinereus. It was purified by the chromatography on DEAE-cellulose. The samples of glucose-isomerasing enzyme are homogeneous according to the results of analytical electrophoresis and ultracentrifugation. Glucose-isomerase is more stable than soluble one. The pH-optima of soluble and immobilized enzymes are 8.5 and 7.5, respectively. The temperature optimum of immobilized enzyme, Km, V, and activation energy do not change during immobilization. The immobilized sample has 58% activity of soluble enzyme.