Lakshmi V, Das Nilanjana
J Environ Biol. 2013 Jul;34(4):701-8.
Caffeine (1,3,7-trimethylxanthine), a natural alkaloid present mainly in tea and coffee products has been suggested as an environmental pollutant. Decaffeination is an important process for the removal of caffeine from coffee industrial wastes. In the present study, caffeine removal (through degradation) by yeast isolate, Trichosporon asahii immobilized on various conventional matrices (sodium alginate, carboxymethyl cellulose, chitosan, agar and agarose) was investigated using the method of entrapment. The biofilm forming ability of T. asahii was monitored by atomic force microscopy and scanning electron microscopy. Exopolysaccharide produced by T asahii biofilm was characterized by FT-IR spectroscopy and HPLC analysis. Caffeine removal from coffee processing industrial effluent was found to be 75 and 80 % by alginate immobilized yeast and yeast biofilm formed on gravels over a period of 48 hr in batch mode. Effectiveness of the process was also tested involving the continuous--flow column studies.
咖啡因（1,3,7 - 三甲基黄嘌呤）是一种主要存在于茶和咖啡制品中的天然生物碱，被认为是一种环境污染物。脱咖啡因是从咖啡工业废料中去除咖啡因的重要过程。在本研究中，采用包埋法研究了固定在各种传统基质（海藻酸钠、羧甲基纤维素、壳聚糖、琼脂和琼脂糖）上的酵母菌株浅黄金色单孢菌对咖啡因的去除（通过降解）情况。通过原子力显微镜和扫描电子显微镜监测浅黄金色单孢菌的生物膜形成能力。通过傅里叶变换红外光谱和高效液相色谱分析对浅黄金色单孢菌生物膜产生的胞外多糖进行了表征。在分批模式下，经48小时，发现海藻酸钠固定化酵母和在砾石上形成的酵母生物膜对咖啡加工工业废水中咖啡因的去除率分别为75%和80%。还通过连续流柱研究测试了该过程的有效性。
