Abstract:Using three representative compounds in tea (caffeine, theobromine and theophylline) as substates to construct a liquid fermentation system of Eurotium cristatum (E.C), the fermentation characteristics of E. C. were preliminarily investigated. Results indicated that the addition of caffeine (0.2 mg/mL) could stimulate the growth of E.C to a certain extent. The content of glucose in the fermentation liquor decreased rapidly, and the pH value progressively declined with the increase of fermentation time until the ninth day, while the content of soluble protein increased first and then decreased. During the fermentation, E.C could not consume the soluble protein as carbon or nitrogen source to maintain its growth, and metabolize caffeine. Similar to caffeine, the theobromine and theophylline (0.08 mg/mL) could also stimulate the growth of Eurotium cristatum to some extent, but could not be consumed as a carbon source. However, the caffeine with concentrations of 0.00091 and 0.00109 mg/mL was detected respectively in the fermentation broth of theobromine and the theophylline, implying that Eurotium cristatum had the ability to synthesize caffeine with precursor of theobromine and theophylline.
