Mannose production by beta-mannosidase from Micromonospora sp. TISTR 1553

Abstract

                   Beta-mannosidase (EC 3.2.1.25) is the most important enzyme for producing of mannose because it cleaves β-1,4 linkage of between mannose at non-reducing end of mannan. Mannose can be used in medical and cosmetic. The β-mannosidase enzyme is produced by plant, animal, human and microorganism. This study focused on screening of β-mannosidase from the three Micromonospora species, Micromonospora aurantionigra TISTR 1532, Micromonospora sp. TISTR 1553 and Micromonospora siamensis TISTR 1554. The screening was performed by culture the three strains in minimum medium supplemented with 0.5% locus bean gum. The enzyme activity was assayed by using 4-nitrophenyl-β-D-mannopyranoside as substrate and the absorbance 420 nm was measured. The result revealed that Micromonospora sp. TISTR 1553 produced the highest β-mannosidase activity. The optimum culture condition was at 30°C for 5 days. Thin layer chromatography (TLC) analysis showed that the degradation of manno-oligosaccharide by crude β-mannosidase yielded high amount of mannose. Further purification procedure of this enzyme in a large scale will be developed.