Three-dimensional fluorescence characteristics of dissolved organic matter produced by Prorocentrum donghaiense Lu  

作　　者：赵卫红 王江涛 陈玫玫 

机构地区：[1]Key Laboratory of Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences [2]Key Laboratory of Marine Chemistry Theory and Technology,Ministry of Education,Ocean University of China

出　　处：《Chinese Journal of Oceanology and Limnology》2009年第3期564-569,共6页中国海洋湖沼学报（英文版）

基　　金：Supported by the High Technology Research and Development Program of China (863 Program) (Nos 2006AA09Z180 and 2004AA639790);the National Natural Science Foundation of China (No 40106013);the National Basic Research Program of China (973 Program) (No 2001CB409703)

摘　　要：Filtration and cross-flow ultrafiltration techniques were used to separate culture media of Prorocentrurn donghaiense at the exponential growth, stationary and decline stages into 〈0.45 μm filtrate, 100 kDa-0.45 μm, 1%100 kDa and 1-10 kDa retentate and 〈1 kDa ultrafiltrate fractions. The fluorescence properties of different molecular weights of dissolved organic matter （DOM） were measured by excitation-emission matrix spectra. Protein-like and humic-like fluorophores were observed in the DOM produced by P. donghaiense. The central positions of protein-like fluorophores showed a red shift with prolonged growth duration, shifting from tyrosine-like properties at the exponential growth stage to tryptophan-like properties at the stationary and decline stages. The excitation wavelengths of protein-like fluorophores exhibited some change in the exponential growth and stationary stages with increased molecular size, but showed little change in the decline stage. However, the emission wavelengths in the decline stage exhibited a blue shift. Very distinct C type and A type peaks in humic-like fluorophores were observed. With a prolonged culture time, the intensities of both of the peaks became strong and the excitation wavelengths of peak A showed a red shift, while the A：C ratios fell. More than 94% of fluorescent DOM was in the lower than 1 kDa molecular weight fraction.Filtration and cross-flow ultrafiltration techniques were used to separate culture media of Prorocentrum donghaiense at the exponential growth,stationary and decline stages into <0.45 μm filtrate,100 kDa-0.45 μm,10-100 kDa and 1-10 kDa retentate and <1 kDa ultrafiltrate fractions.The fluorescence properties of different molecular weights of dissolved organic matter(DOM) were measured by excitation-emission matrix spectra.Protein-like and humic-like fluorophores were observed in the DOM produced by P.donghaiense.The central positions of protein-like fluorophores showed a red shift with prolonged growth duration,shifting from tyrosine-like properties at the exponential growth stage to tryptophan-like properties at the stationary and decline stages.The excitation wavelengths of protein-like fluorophores exhibited some change in the exponential growth and stationary stages with increased molecular size,but showed little change in the decline stage.However,the emission wavelengths in the decline stage exhibited a blue shift.Very distinct C type and A type peaks in humic-like fluorophores were observed.With a prolonged culture time,the intensities of both of the peaks became strong and the excitation wavelengths of peak A showed a red shift,while the A:C ratios fell.More than 94% of fluorescent DOM was in the lower than 1 kDa molecular weight fraction.

关 键 词：dissolved organic matter FLUORESCENCE excitation-emission matrix spectrum Prorocentrum donghaiense Lu 

分 类 号：Q945[生物学—植物学]