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Extractive Cultivation of Recombinant Escherichia coli using Aqueous Two‐Phase Systems for Production and Separation of Intracellular Heat Shock Proteins
Author(s) -
Umakoshi Hiroshi,
Yano Koji,
Kuboi Ryoichi,
Komasawa Isao
Publication year - 1996
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp9500472
Subject(s) - escherichia coli , potassium phosphate , groes , groel , ethylene glycol , peg ratio , heat shock protein , recombinant dna , chromatography , chemistry , lysis , aqueous solution , biology , biochemistry , organic chemistry , finance , economics , gene
The extractive cultivation of recombinant Escherichia coli cells to produce, release, and separate heat shock proteins (HSPs; GroEL and GroES) using poly(ethylene glycol) (PEG)/dextran (Dex) aqueous two‐phase systems was developed. The growth rate of E . coli OW10/pND5 cells in the PEG/Dex two‐phase media was almost the same value as that in the control media. The addition of 0.1 M potassium phosphate salts (KPi) increased the productivity of HSPs with keeping the growth rate of E . coli cells relatively high. The partition coefficients of HSPs were improved to greater values when phosphate salts were added at a concentration of more than 0.1 M. As a result, PEG/Dex systems supplemented with 0.1 M KPi were found to be the optimized two‐phase systems for the extractive cultivation of E . coli cells. In the systems, the HSPs were selectively partitioned to the top phase while cells occupied the bottom phase and the interface between the two phases. This integrated process was extended to a semicontinuous operating mode, where the top phase containing the HSPs was recovered following intermittent heating and ultrasonic irradiation. The bottom phase containing cells and cell debris was recycled together with new top phase solution to repeat production and recovery of HSPs.