TY - JOUR
T1 - Amylase partitioning and extractive bioconversion of starch using thermoseparating aqueous two-phase systems
AU - Li, M.
AU - Kim, J. W.
AU - Peeples, T. L.
N1 - Funding Information:
This work was supported in part by NSF Career grant BES 9702588 and by NASA NAG8-1593.
PY - 2002/1/31
Y1 - 2002/1/31
N2 - The effectiveness of thermoseparating polymer-based aqueous two-phase systems (ATPS) in the enzymatic hydrolysis of starch was investigated. In this work, the phase diagrams of PEO-PPO-2500/ammonium sulfate and PEO-PPO-2500/magnesium sulfate systems were determined at 25°C. The partition behavior of pure α-amylase and amyloglucosidase in four ATPS, namely, PEO-PPO/(NH4)2SO4, PEO-PPO/MgSO4, polyethylene glycol (PEG)/(NH4)2SO4, and PEG/MgSO4, was evaluated. The effects of phase-forming component concentrations on the enzyme activity and partitioning were assessed. Partitioning of a recombinant, thermostable α-amylase (MJA1) from the hyperthermophile, Methanococcus jannaschii was also investigated. All of the studied enzymes partitioned unevenly in these polymer/salt systems. The PEO-PPO-2500/MgSO4 system was extremely attractive for starch hydrolysis. Polymer-based starch hydrolysis experiments containing PEO-PPO-2500/MgSO4 indicated that the use of ATPS had a significant effect on soluble starch hydrolysis. Batch starch hydrolysis experiments with PEO-PPO/salt two-phase systems resulted in higher production of maltose or glucose and exhibited remarkably faster hydrolysis. A 22% gain in maltose yield was obtained as a result of the increased productivity. This work is the first reported application of thermoseparating polymer ATPS in the processing of starches. These results reveal the potential for thermoseparating polymer-enhanced extractive bioconversion of starch as a practical technology.
AB - The effectiveness of thermoseparating polymer-based aqueous two-phase systems (ATPS) in the enzymatic hydrolysis of starch was investigated. In this work, the phase diagrams of PEO-PPO-2500/ammonium sulfate and PEO-PPO-2500/magnesium sulfate systems were determined at 25°C. The partition behavior of pure α-amylase and amyloglucosidase in four ATPS, namely, PEO-PPO/(NH4)2SO4, PEO-PPO/MgSO4, polyethylene glycol (PEG)/(NH4)2SO4, and PEG/MgSO4, was evaluated. The effects of phase-forming component concentrations on the enzyme activity and partitioning were assessed. Partitioning of a recombinant, thermostable α-amylase (MJA1) from the hyperthermophile, Methanococcus jannaschii was also investigated. All of the studied enzymes partitioned unevenly in these polymer/salt systems. The PEO-PPO-2500/MgSO4 system was extremely attractive for starch hydrolysis. Polymer-based starch hydrolysis experiments containing PEO-PPO-2500/MgSO4 indicated that the use of ATPS had a significant effect on soluble starch hydrolysis. Batch starch hydrolysis experiments with PEO-PPO/salt two-phase systems resulted in higher production of maltose or glucose and exhibited remarkably faster hydrolysis. A 22% gain in maltose yield was obtained as a result of the increased productivity. This work is the first reported application of thermoseparating polymer ATPS in the processing of starches. These results reveal the potential for thermoseparating polymer-enhanced extractive bioconversion of starch as a practical technology.
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U2 - 10.1016/S0168-1656(01)00382-0
DO - 10.1016/S0168-1656(01)00382-0
M3 - Article
C2 - 11690691
AN - SCOPUS:0037203568
SN - 0168-1656
VL - 93
SP - 15
EP - 26
JO - Journal of Biotechnology
JF - Journal of Biotechnology
IS - 1
ER -