The accumulation dynamics of cellulolytic enzymes in culture media of the basidiomycete fungi Panus tigrinus, Pleurotus ostreatus, Fomes fomentarus, and the micromycete Aspergillus terreus were studied during a long incubation period. It was found that A. terreus was the most active producer of cellulolytic enzymes among the studied fungi. Two protein fractions with cellulase activity were isolated using gel filtration and ion-exchange chromatography. PAAG electrophoresis showed that fraction-I consisted of four components; fraction-II, an electrophoretically homogeneous protein.It is known that cellulolytic enzymes are produced by various microorganisms belonging to various taxonomic groups [1,2]. Cellulases have broad applications and are used mainly in food, textile, chemical, medical, pharmaceutical, paper, and wood processing industries. They are also added to animal feed and to agricultural process wastes [3][4][5][6].The goal of our work was to study the ability of wood-destroying fungi to produce highly active cellulases and to produce active preparations of cellulolytic enzymes.The accumulation dynamics of cellulolytic enzymes in culture media of the fungi Panus tigrinus, Pleurotus ostreatus, Fomes fomentarus, and Aspergillus terreus were determined during different periods of the growth and development, from 7 to 14 days.The results show that A. terreus was the best producer of cellulase compared with the other fungi. The maximum endoglucanase activity was observed 10 days from the start of growth. Therefore, 10-day culture liquid of A. terreus was first filtered through glass wool and then through a millipore filter (0.2 µm pore size) to separate the supernatant from the cell culture in order to isolate enzyme components of the cellulase complex. Cellulase activity in solution was determined by the Wood and Bhat method [7] using Na-CMC (1%) as substrate. The solution (220 mL) contained 106.1 units of total cellulase activity ( Table 1).The protein concentration determined by the Lowry method [8] indicated 154 mg of protein in the collected culture medium from A. terreus. The specific activity of the cellulolytic enzyme in the culture medium was 0.688 U/mg of protein.Then the culture medium was concentrated in a rotary evaporator to 17 mL. The total cellulase activity and protein concentration in the concentrated enzyme solution was 83.38 U and 108.56 mg, respectively. Analysis of the proteins by SDS-PAAG electrophoresis showed nine protein bands with molecular weights from 17 to 120 kDa in the concentrated enzyme solution.
The chemical composition of bufadienolides isolated from the venom of Bufo viridis green toad occurring in Central Asia was determined and their biological properties were studied. Six individual bufadienolides were isolated by reverse-phase chromatography on a Lichrosorb RP-8 (10 m) column in amounts sufficient for qualitative analysis. Two of these were previously identified as arenobufagin and gamabufotalin by NMR spectroscopy and x-ray diffraction methods. The chemical structures of four other bufadienolides are now established by NMR spectroscopy and HPLC. These compounds have been identified as telocinobufagin (3b,5b,14b-trihydroxybufa-20,22-dienolide), marinobufagin (3b,5b-hydroxy-14,15b-epoxybufa-20,22-dienolide), bufarenogin (3b,12b,14b-hydroxybufa-20,22-dienolide), and bufalin (3b,14b-hydroxybufa-20,22-dienolide).
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