Three-dimensional fluorescence as a tool for investigating the dynamics of dissolved organic matter in the Lake Biwa watershed

Limnology ◽  
2005 ◽  
Vol 6 (2) ◽  
pp. 101-115 ◽  
Author(s):  
Khan M. G. Mostofa ◽  
Takahito Yoshioka ◽  
Eiichi Konohira ◽  
Eiichiro Tanoue ◽  
Kazuhide Hayakawa ◽  
...  
2008 ◽  
Vol 58 (8) ◽  
pp. 1609-1614
Author(s):  
T. Kusakabe ◽  
K. Ikeda ◽  
Y. Shimizu ◽  
S. Higashi ◽  
Y. Kawabata ◽  
...  

The objectives of this research were to investigate seasonal and spatial variations in (1) sorption of pyrene and its derivatives onto dissolved organic matter (DOM) and (2) fluorescence properties of DOM in Lake Biwa, Japan. In the case of pyrene, sorption coefficient (Kdoc) of Lake Biwa DOM seasonally changed from 1,200 to 3,800 L/kgC. Vertical distribution of Kdoc was affected by thermocline formation in summer, while it was uniformly distributed as a result of vertical mixing in winter. Functional groups affected sorption of pyrene onto Lake Biwa DOM in different manner from that onto Suwannee River fulvic acid. Three-dimensional excitation emission matrices (3D-EEMs) fluorescence spectroscopy was applied to characterize Lake Biwa DOMs and indicated the existence of at least two fluorophores. The two major peaks at Ex230/Em300 and Ex230/Em425 originated from protein-like and fulvic/humic-like substances, respectively. The peak at Ex230/Em300 showed the maximum fluorescence intensity at a depth of 5 m and could be affected by stratification of the water column in summer. On the other hand, the peak at Ex230/Em425 showed similar profiles both in summer and in winter. These results demonstrably showed that sorption of micropollutants and fluorescence properties of Lake Biwa DOMs were seasonally and spatially varied.


2012 ◽  
Vol 28 (7) ◽  
pp. 675-681 ◽  
Author(s):  
Etsu YAMADA ◽  
Shinya OHARA ◽  
Takashi UEHARA ◽  
Takaaki HIROTA ◽  
Naoko HATORI ◽  
...  

2016 ◽  
Vol 42 (3) ◽  
pp. 571-579 ◽  
Author(s):  
Kazuhide Hayakawa ◽  
Reiji Kojima ◽  
Chizuru Wada ◽  
Tomoyo Suzuki ◽  
Yuko Sugiyama ◽  
...  

Water ◽  
2017 ◽  
Vol 9 (4) ◽  
pp. 266 ◽  
Author(s):  
Weifang Qiao ◽  
Xinyi Wang ◽  
Xiaoman Liu ◽  
Xiaoge Zhen ◽  
Jianwei Guo ◽  
...  

2009 ◽  
Vol 58 (4) ◽  
pp. 231-240 ◽  
Author(s):  
Shinya Ohara ◽  
Takashi Uehara ◽  
Keiichiro Kimura ◽  
Tetsuro Yoshida ◽  
Shohei Fujiwara ◽  
...  

BioResources ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. 8937-8952
Author(s):  
Peng Zhan ◽  
Jingjing Sun ◽  
Fang Wang ◽  
Lin Zhang ◽  
Jienan Chen

Enzymatic saccharification is a key step in the green conversion of lignocellulose to biofuels and other products. A key deficiency in common biocatalytic systems, such as Trichoderma reesei, is the insufficient presence of β-glucosidase (BGL). This study intended to develop an efficient process of BGL production as an enhancement to the T. reesei system. The authors investigated the process optimization of BGL by the mutant strain Aspergillus niger C112, which was previously developed in the authors’ laboratory. The culture medium and process (carbon, nitrogen, temperature, and pH) were optimized for cost-effective BGL production, which led to a maximum BGL activity of 8.91 ± 0.35 U/mL. In addition, the dynamics of the physio-chemical parameters (zeta potential and dissolved organic matter) of the process were studied and showed good correlations to the yield of BGL. Furthermore, a three-dimensional excitation-emission matrix fluorescence spectroscopy was successfully applied for analyzing the component, origin, and dynamics of dissolved organic matter, which contributed to a further understanding and optimization of BGL production.


2005 ◽  
Vol 54 (9) ◽  
pp. 923-928 ◽  
Author(s):  
Kenichi NAGAI ◽  
Sinichi AOKI ◽  
Yasuro FUSE ◽  
Etsu YAMADA

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