[Isolation and characterization of microorganisms with mannanase activity]

Area of Science:

• Microbiology
• Enzymology

Background:

• Mannanase enzymes are crucial for breaking down mannans, complex carbohydrates found in yeast cell walls.
• Understanding the specificities of mannanase activity is important for biotechnological applications.

Purpose of the Study:

• To isolate and characterize soil microorganisms synthesizing extracellular mannanase.
• To determine the substrate specificity of the isolated mannanases, particularly their activity against different mannan linkages.
• To assess the potential of mannanase in yeast cell wall lysis.

Main Methods:

• Isolation of soil microorganisms using baker's yeast mannan as the sole carbon source.
• Identification of active microbial strains and characterization of their mannanase-producing capabilities.
• Enzymatic assays to determine the hydrolysis activity of mannanases against various alpha- and beta-mannan linkages.

Main Results:

• Twenty-three soil microorganism strains producing extracellular mannanase were isolated.
• Ten active strains were identified, demonstrating the ability to hydrolyze mannans with alpha-1,2- and alpha-1,6-bonds.
• Five strains hydrolyzed alpha-1,3-bonds, and two strains showed activity against beta-mannane with 1,3 and 1,4 bonds.
• The tested mannanases exhibited very low lytic activity against Saccharomyces and Candida yeast cells.

Conclusions:

• Soil microorganisms are a viable source of diverse mannanase enzymes.
• Isolated mannanases exhibit specificities for different mannan glycosidic linkages.
• Mannanase enzymes alone are insufficient for the independent lysis of yeast cell walls, suggesting a need for synergistic enzymatic action.