Gokulakrishnan S, Chandraraj K, Gummadi Sathyanarayana N
Department of Biotechnology, Indian Institute of Technology-Madras, Chennai 600 036, India.
Int J Food Microbiol. 2007 Feb 15;113(3):346-50. doi: 10.1016/j.ijfoodmicro.2006.07.005. Epub 2006 Sep 25.
Several microorganisms isolated from soil were tested for their ability to utilize caffeine as the sole carbon and nitrogen source. The isolate identified as Pseudomonas sp. GSC 1182 showed 80% degradation of caffeine in 48 h when caffeine was used as the sole carbon and nitrogen source. In the presence of sucrose (5 g/l), 100% degradation of caffeine was achieved within 36-40 h. The degradation rate was also found to increase when fructose, lactose and galactose were used as carbon source. The isolate showed decreased level (<10%) of caffeine degradation in the presence of glucose. At an initial pH of 6.0, the complete degradation of caffeine was attained in 24 h. The addition of urea and ammonium sulfate as external nitrogen source decreased the caffeine degradation to 35% and 70% respectively.
对从土壤中分离出的几种微生物进行了测试,以考察它们利用咖啡因作为唯一碳源和氮源的能力。鉴定为假单胞菌属GSC 1182的分离株,当咖啡因用作唯一碳源和氮源时,在48小时内可使咖啡因降解80%。在蔗糖(5克/升)存在的情况下,36至40小时内可实现咖啡因100%的降解。当果糖、乳糖和半乳糖用作碳源时,降解率也会提高。在葡萄糖存在的情况下,该分离株的咖啡因降解水平降低(<10%)。在初始pH值为6.0时,24小时内可实现咖啡因的完全降解。添加尿素和硫酸铵作为外部氮源,咖啡因降解率分别降至35%和70%。