Production of Microbial Cellulose and Acids in Kombucha

Abstract

Factors affecting the production of bacterial cellulose, organic acids in Kombucha fermentation were investigated. Kombucha was obtained by the fermentation (for 12 days at 30℃) of the green/black tea extract, supplemented with 10% white sugar, using an Oriental tea fungus as starter. Higher initial pH increased acid production with decreased cellulose production. With a cellulose pellicle or tea fungus broth as a starter, a 1～3 mm thick cellulose layer developed as a top layer every four days,, was removed subsequently while continuing fermentation. Addition of 30 mL tea fungus broth (13%, v/v) in Kombucha fermentation resulted in maximum production of a cellulose pellicle, indicating weak acid production. Yield of cellulose production at an early stage of fermentation was also higher when Kombucha was inoculated with a cellulose pellicle. In fact, addition of 1% (v/v) alcoholic beverage in the Kombucha fermentation activated the cellulose production, coupled with four times higher acid production.