Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA, 30602-4712, USA.
Folia Microbiol (Praha). 2013 May;58(3):195-200. doi: 10.1007/s12223-012-0197-3. Epub 2012 Sep 28.
The aim of the present study was to evaluate the effect of the initial caffeine concentration (1-8 g/L) on growth and caffeine consumption by Aspergillus tamarii as well as pellet morphology, in submerged fermentation. Caffeine was used as sole nitrogen source. At 1 g/L of initial caffeine concentration, caffeine degradation was not affected, resulting in a production of 8.7 g/L of biomass. The highest biomass production (12.4-14.8 g/L) was observed within a range of 2 to 4 g/L of initial caffeine concentration. At these initial caffeine concentrations, after 96 h of fermentation, 41-51 % of the initial caffeine was degraded. Using an initial caffeine concentration of 2-3 g/L, the highest specific growth rate was observed (μ = 0.069 1/h). Biomass production decreased at 8 g/L of initial caffeine concentration. A. tamarii formed mainly pellets at all concentrations tested. The size of the pellet decreased at a caffeine concentration of 8 g/L.
本研究旨在评估初始咖啡因浓度（1-8 g/L）对土曲霉生长和咖啡因消耗的影响，以及在深层发酵中的颗粒形态。咖啡因被用作唯一的氮源。在 1 g/L 的初始咖啡因浓度下，咖啡因降解不受影响，导致产生 8.7 g/L 的生物量。在 2 到 4 g/L 的初始咖啡因浓度范围内观察到最高的生物量生产（12.4-14.8 g/L）。在这些初始咖啡因浓度下，发酵 96 小时后，初始咖啡因中有 41-51%被降解。使用 2-3 g/L 的初始咖啡因浓度，观察到最高的比生长速率（μ=0.069 1/h）。在 8 g/L 的初始咖啡因浓度下，生物量生产减少。土曲霉在所有测试浓度下主要形成颗粒。在 8 g/L 的咖啡因浓度下，颗粒的大小减小。
