1998 Fiscal Year Final Research Report Summary
Study on The Development of Functional Aqueous Two-Phase Systems for Separation and Recovery of Bio-Products
| Project/Area Number |
08455364
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
反応・分離工学
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
KAJIUCHI Toshio Tokyo Institute of Technology, Graduate School of Science and Engineering, Professor (30016555)
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| Project Period (FY) |
1996 – 1998
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| Keywords | Aqueous two-phase system / coarse separation / temperature dependency / pH dependency / Two-step partition / reactive ATPS / functional ATPS / PAOMA |
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| Research Abstract |
Aqueous two-phase system(ATPS) is expected as one of coarse separation technology of macromolecules like as proteins from fermentation broth in mild conditions. In this study, development of new functional aqueous two-phase system was investigated focusing following three points ; 1) pH dependency, 2) temperature dependency and 3) reactivity. The new two-phase system was composed of polyalkyleneoxide-maleic acid copolymer(PAOMA) and potassium phosphate(PK). PAOMA, a poly-electrolyte, has better compatibility with enzymes and greater pH-sensibility than polyethylene glycol which is a traditional ATPS composed polymer.
Through the partitioning experiments of proteins, mainly enzymes, the following results are given.
1) Selectivity for objective materials : Maleic acid groups of the copolymer are dissociated in aqueous condition, while around pH 8 and temperature under 4℃ maleic acid groups are reacted with amino groups on the protein surface. Using this reaction, the protein which has tendency to be portioned to salt phase is able to be partitioned to the polymer rich phase.
2) Sensibility of partitioning behavior to pH condition : Because of polyelectrolytic characteristic of the copolymer and the amphoteric property of proteins, the new ATPS has very sensitive property to pH condition than the traditional PEG/DEX systems.
3) Temperature dependency on partitioning behavior : Cloud point phenomenon of the polymer is applied for protein recovery as two step extraction ; protein is partitioned in the polymer rich phase in 4℃ condition and polymer rich phase is withdrawing and heating at 25℃. Then protein is recovered from new water rich phase.
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