Applied and Industrial Microbiology Laboratory, Department of Biotechnology, Indian Institute of Technology-Madras, Chennai-36, India.
Appl Microbiol Biotechnol. 2011 Aug;91(4):1007-17. doi: 10.1007/s00253-011-3319-y. Epub 2011 May 14.
The growth of Pseudomonas sp. was studied in fed-batch process with an aim to improve the caffeine degradation rate and caffeine demethylase activity. The effects of varying initial caffeine concentrations in the batch mode, increase in the number of feeds, varying feed flow rates, and added nutrients to the feed on the fed-batch process were investigated. A maximum caffeine degradation rate of 0.82 g/L h and maximum caffeine demethylase activity of 2.6 U/mg were achieved using manual intermittent pulse feeds of caffeine with substrate concentration as feedback parameter for the fed batch started with an initial caffeine concentration of 3 g/L. A slight increase in the caffeine degradation rate (0.85 g/L h) and caffeine demethylase activity (3.4 U/mg) was observed when the additional nutrients were added along with caffeine in the feed. This is the first report showing complete degradation of large magnitudes of caffeine amounting to 237 g in 75 h. These results show that the fed-batch conditions achieved in this study using Pseudomonas sp. facilitate the development of a sustainable bioprocess to degrade the high concentrations of caffeine in industrial effluents.
研究了分批补料培养过程中假单胞菌的生长情况，目的是提高咖啡因的降解率和咖啡因脱甲基酶的活性。考察了分批模式下初始咖啡因浓度、补料次数、补料流速和补料中添加营养物质的变化对补料过程的影响。以初始咖啡因浓度为 3 g/L 开始的补料分批培养，采用基于底物浓度的手动间歇脉冲补加咖啡因作为反馈参数，可获得最大的咖啡因降解率（0.82 g/L·h）和最大的咖啡因脱甲基酶活性（2.6 U/mg）。当在补料中添加咖啡因和额外的营养物质时，咖啡因的降解率（0.85 g/L·h）和咖啡因脱甲基酶活性（3.4 U/mg）略有增加。这是首次报道在 75 h 内完全降解了高达 237 g 的咖啡因。这些结果表明，本研究中使用假单胞菌在分批补料条件下可促进开发可持续的生物处理工艺，用于降解工业废水中的高浓度咖啡因。
