ENZYMATIC UPCYCLING OF BACTERIAL CELLULOSE FROM KOMBUCHA TO OBTAIN CELLOBIOSE

The production of kombucha generates bacterial cellulose (BC) as a by-product, which is usually discarded. However, BC can be a source of cellobiose, a disaccharide with prebiotic benefits. In this study, the yield of cellobiose released from BC collected from a medium-sized kombucha producer was evaluated by enzymatic hydrolysis using the commercial cocktail Celluclast 1.5 L. The BC was hydrolyzed at solid contents of 2, 3 and 4% (m/v), enzyme dosage of 2.2 U/ g cellulose, pH 5, 50 degrees C, and 150 rpm for 72 h. Industrial BC was characterized by FTIR and XRD to confirm the presence of common BC characteristics. The same analyses were performed after enzymatic hydrolysis, resulting in a change in crystallinity. The maximum cellobiose production (10-11 g/L) was obtained with 4% BC (w/v) in 48 h of hydrolysis; there was no significant difference when the time was extended to 72 h. The maximum glucose production under the same conditions was 3 g/L, showing that Celluclast 1.5 L has high cellobiose selectivity (78%). However, the cellobiose yield only ranged from 35 to 26%, indicating that cellobiose accumulation in the medium caused enzyme inhibition.