Isolation and partial characterization of yeast mannan hydrolysing enzymes from bacterial isolates

A range of aerobic, mesophilic bacterial strains capable of producing extracellular alpha-mannanase and alpha-mannosidase enzymes were isolated from various natural habitats using yeast cell wall material as the selective medium. Five of them were capable of producing extracellular alpha-mannosidase and alpha-mannanase on yeast mannan as the sole carbon substrate, and they were tentatively identified to the genus level as Arthrobacter, Streptomyces, Pseudomonas, Bacillus and Acinetobacter. Among these strains, Arthrobacter M-02 showed the highest biosynthetic activity of the enzymes. The crude enzyme preparations from the strains were active at pH 4 to 9, reaching a maximum activity between 5.5 and 6.8. The crude Arthrobacter M-02 alpha-mannosidase was more thermostable than that of the other strains, but the alpha-mannanase of the strain was thermolabile.