Mikrobiol. Z. 2019; 81(1):72-83. Russian.
β−Mannanase and α−Galactosidase Activity of Micromycetes
Borzova N.V., Brovarskaya O.S., Varbanets L.D., Nakonechna L.T., Kurchenko I.N.
Zabolotny Institute of Microbiology and Virology, NAS of Ukraine
154 Akad. Zabolotny Str., Kyiv, 03143, Ukraine
The aim of research was to study the mannan-degrading activity of isolated micromycete cultures. Methods. The identification of cultures was carried out on a complex of cultural and morphological characteristics. β-Mannanase activity was determined by the dinitrosalicylic method, synthetic nitrophenyl substrates were used to assay other glycosidase activities. Results. From the plant substrates and bodies of bees nine strains of micromycetes were isolated. As a result the identification of the culture was attributed to the species Rhizopus oryzae Went & Prins. Geerl. (3 strains), Penicillium cyclopium Westling (2 strains), Aspergillus sp. (1 strain), Penicillium expansum Lk (3 strains). For the first time β-mannanase and α-galactosidase activity have been demonstrated in representatives of the species R. oryzae, P. cyclopium, P. expansum. It was found that galactomannan guar (0.5%) provides high β-mannanase (1.5–8.5 U/ml) and α-galactosidase (1.1–2.4 U/ml) activity in the culture fluid of the micromycetes. The best sources of nitrogen for culture growth and enzyme synthesis were peptone, yeast autolysate and ammonium sulfate (at a concentration of 5.0, 1.0, and 1.0 g/l respectively). The maximum mannan-degrading activity of micromycetes was observed at 25°C on the 5th day of cultivation. Conclusions. New strains with high β-mannanase and α-galactosidase activity were obtained, promising for use in biotechnological processes of degradation of plant raw materials with a high content of mannans.
Keywords: Rhizopus oryzae, Penicillium cyclopium, Penicillium expansum, β-mannanase activity, α-galactosidase activity, guar galactomannan.
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