Cellobiose Octaacetate Research Articles

Effect of Nutrients and Cellobiose Octaacetate on Cellulolytic Enzyme Productions by <i>Streptomyces albolongus</i>

The cellulolytic mesophilic isolate Streptomyces albolongus (A5) was used to determine the effect of nitrogen and carbon sources on the production of cellulolytic enzymes using cellobiose octaacetate (COA) as an inducer. The isolate was able to degrade various cellulosic carbon sources. However, the rate of degradation, production of extracellular protein, reducing sugar, saccharification and production of enzyme were enhanced when 0.6% COA was used as an inducer in addition to the main substrate. Among the nitrogen sources tested, beef extract showed maximum production of the enzyme (136.7 U/ml CMCase) in Winstead's medium. The enzyme production was further enhanced in the medium supplemented with 0.6% COA, which corresponded to 154.69 U/ml CMCase activity. Among the carbon sources, carboxymethylcellulose (CMC) was found to be the best carbon source and again supplementation of the medium with 0.6% COA enhances CMCase production. Other than CMCase activity, the organism also produced appreciable levels of filter paper cellulase (FPase), avicelase and â-glucosidase activities.Keywords: Streptomyces albolongus, Carboxymethylcellulose (CMC), Cellobiose octaacetate (COA), InductionDOI: http://dx.doi.org/10.3329/bjm.v24i1.1243 Bangladesh J Microbiol, Volume 24, Number 1, June 2007, pp 70-72

Induction of Cellulase Biosynthesis by Cellobiose Octaacetate in <i>Aspergillus humicola</i>

Aspergillus humicola, one of the major cellulase-producing fungi, was used in this study for carboxymethylcellulase (CMCase) production using Winstead's basal broth supplanted with cellobiose octaacetate (COA), a synthetic carbon source. Under all conditions, the enzyme biosynthesis was remarkably increased when the inducer COA was added to the production medium containing carboxymethylcellulose (CMC). Maximum enzyme production (1.62 U/ml) was achieved in COA-containing at 37°C. The enzyme production was highest at initial pH 5.5 and after 7 days incubation. The enzyme exhibited maximum activity at 40°C with a reaction pH 5.5. CMCase activity was inhibited by its own substrate CMC at concentration higher than 1.0%. The study clearly demonstrated that COA is a good inducer for extracellular CMCase production by the fungus. Keywords: Aspergillus humicola, Carboxymethylcellulase (CMCase), Carboxymethylcellulose (CMC), Cellobiose octaacetate (COA)DOI: http://dx.doi.org/10.3329/bjm.v23i2.889 Bangladesh J Microbiol, Volume 23, Number 2, December 2006, pp 174-176

Conversion of Cellobiose into Lactose

Benzyl 2, 3, 6-tri-O-acetyl-4-O-(2,3-di-O-acetyl-4,6-di-O-methylsulfonyl-β-d-glucopyranosyl)-β-d-glucopyranoside (VI) was prepared from α-cellobiose octaacetate. Displacement of the sulfonyl esters of VI with acyloxy-groups in N, N-dimethyl formamide in the presence of sodium benzoate gave 4-O-β-d-galactopyranosyl-d-glucopyranose derivative (lactose derivative). Elimination of blocking groups of the derivative yielded lactose hydrate (IX), though the overall yield of lactose from cellobiose octaacetate was less than 2%.

The Existence of the Cellobiose Residue in Cellulose

THE chemical evidence for the view that cellobiose is preformed in cellulose is considerably strengthened by some observations we have made on the acetolysis of trimethyl cellulose. Under mild conditions of treatment at low temperatures fully methylated cellulose suffers cleavage to give a diacetyl-hexa-methyl cellobiose, which is readily transformed into crystalline heptamethyl β-methylcellobioside. The experimental conditions under which this derivative of cellobiose is isolated preclude its occurrence as a reversion product of the reaction. Moreover, the yield of the crystalline β-cellobioside is equal to that of cellobiose octa-acetate obtained by the direct acetolysis of cellulose.