Характеристика продуктивности дрожжей Candida ethanolica штамма BKM Y-2300 T

Abstract

In the modern world, the applying of microorganisms as producers of various valuable compounds is relevant. Such producers are often yeast Candida, which are used to synthesize various products – proteins, enzymes, vitamins. One of the representatives of the genus, Candida ethanolica, is interesting because it uses ethanol as a carbon source. Synthetic ethanol is a convenient raw material for the biotechnological process, since it has a lower cost compared to chemically pure carbohydrates, is well water-soluble and does not contain impurities. Since the C. ethanolica is insufficiently studied as a biotechnological object, the aim of the research was the obtaining new information about the strain Candida ethanolica (BKM strain Y-2300 T). The main morphological, cultural, physiological and biochemical properties of the yeast strain were studied. Part of them turned out to be typical for most yeast of genus Candida. In addition, the strain was facultatively anaerobic with respect to oxygen. In addition, the most suitable carbon source and its optimal concentration were selected for this strain. It showed the greatest preference to ethanol when grown in the presence of various carbon sources (carbohydrates, alcohols, oils). The biggest increasing of cell number and biomass was observed if an ethanol content in the medium was of 1.5% vol. The optimal conditions for laboratory cultivation for this strain were determined: aeration degree (200 rpm); temperature 37 ° C; pH of the medium (7.0). The yeast were resistant to salt concentrations from 4.5 to 5.0%. The strain was also tested for the activity of some enzymes important in the food and processing industry: saccharolytic, proteolytic, lipolytic, amylolytic, catalase, and urease. The most active enzymes were that hydrolyze sucrose, lipids and proteins. The ability of C. ethanolica to intracellular synthesis of protein, carbohydrates and vitamins was evaluated. This strain formed a small amount of carbohydrates and vitamins, but its protein quantity was quite substantial. The maximum amount of protein in the cells accumulated after 4 hours (from the start of cultivation) and was 31.10 %. This value was at the level of some well-known producers of cell protein. Thus, the studied strain is a potentially valuable producer for the biotechnology industry as a source of cell protein, glycosidase, lipase and protease. Further studies that are more specific are required to exploit the biosynthetic potential of this strain in industry.