The exopolysaccharide (EPS) production by psychrophilic Antarctic yeast Sporobolomyces salmonicolor AL₁ reached the maximum yield in medium containing sucrose (50 g/L) and diammonium sulfate (2.5 g/L) after a 5-d fermentation (5.64 g/L) at 22 °C, the dynamic viscosity of the culture broth reaching (after 5 d) 15.4 mPa s. EPS showed a mannan-like structure and high molar mass, and did not affect cellular viability and proliferation of murine macrophages. It exhibited also a protective effect against the toxic activity of Avarol.

• MeSH
• Basidiomycota isolation & purification   metabolism   MeSH
• Culture Media chemistry   MeSH
• Macrophages physiology   MeSH
• Mannans analysis   MeSH
• Molecular Weight MeSH
• Mice MeSH
• Polysaccharides chemistry   metabolism   MeSH
• Sesquiterpenes antagonists & inhibitors   MeSH
• Cell Survival drug effects   MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Antarctic Regions MeSH
• Names of Substances
• avarol MeSH Browser
• Culture Media MeSH
• Mannans MeSH
• Polysaccharides MeSH
• Sesquiterpenes MeSH

Psychrophilic Antarctic yeasts produce polysaccharides in different concentrations. According to morphological, cultural, physiological and biochemical characteristics, the best producer strain was identified as Cryptococcus flavus A(51). The highest values for viscosity (59.1 mPa s) and crude polysaccharide productivity (5.75 g/L) were obtained in a medium containing 5 % sucrose and 0.25 % (NH(4))(2)SO(4), at 24 degrees C for 6 d. The chemical composition and sugar constituents of the crude exopolysaccharide were determined (92.5 % saccharides, 3.34 % protein, and 4.16 % ash). The monosaccharide composition of the exopolysaccharide obtained from C. flavus strain AL(51) was established (55.1 % mannose, 26.1 % glucose, 9.60 % xylose, 1.90 % galactose). The microbial biopolymer has a high molar mass and homogeneity: 82 % of it had M 1.01 MDa.

• MeSH
• Yeasts chemistry   isolation & purification   metabolism   MeSH
• Polysaccharides chemistry   metabolism   MeSH
• Spheniscidae microbiology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Antarctic Regions MeSH
• Names of Substances
• Polysaccharides MeSH

The presence of phytase activity was demonstrated in 26 strains of rabbit cecal bacteria. In 25 strains a low phytase activity, 0.10-0.62 micromol phosphate released per min per mg protein, was found. High activity (2.61 micromol/min per mg protein) was found in the strain PP2 identified as Enterococcus hirae. Phytase activity was cell-associated, being higher in the cell extract than in the cell walls. Extracellular phytase activity and cell-associated phosphatase activity were not detected. Phytase activity was optimal around pH 5.0, which is below the physiological cecal pH range. The K (m) determined using the Lineweaver-Burk plot was 0.19 micromol/mL. Cations Fe(3+), Cu(2+) and Zn(2+) at 0.5 mmol/L decreased phytase activity in sonicated cells of E. hirae by 99.4, 90.7 and 96.5 %, respectively. In contrast, Mg(2+) increased activity by 11.0 %. Characteristics of E. hirae phytase (pH optimum, K (m), cation sensitivity) were similar to those of other bacterial phytases reported in the literature. Other bacteria with a high phytase activity may be present in the rabbit cecum but remain to be identified.

• MeSH
• 6-Phytase chemistry   metabolism   MeSH
• Bacteria chemistry   enzymology   isolation & purification   MeSH
• Bacterial Proteins chemistry   metabolism   MeSH
• Cecum microbiology   MeSH
• Enterococcus chemistry   genetics   isolation & purification   MeSH
• Kinetics MeSH
• Rabbits MeSH
• Enzyme Stability MeSH
• Animals MeSH
• Check Tag
• Rabbits MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• 6-Phytase MeSH
• Bacterial Proteins MeSH