Intensified expression and purification of a recombinant biosurfactant protein

Dwyer, Mirjana Dimitrijev, Brech, Michael, Yu, Lei and Middelberg, Anton P.J. (2014) Intensified expression and purification of a recombinant biosurfactant protein. Chemical Engineering Science, 105 12-21. doi:10.1016/j.ces.2013.10.024

Author Dwyer, Mirjana Dimitrijev
Brech, Michael
Yu, Lei
Middelberg, Anton P.J.
Title Intensified expression and purification of a recombinant biosurfactant protein
Journal name Chemical Engineering Science   Check publisher's open access policy
ISSN 0009-2509
Publication date 2014-02-24
Year available 2013
Sub-type Article (original research)
DOI 10.1016/j.ces.2013.10.024
Open Access Status
Volume 105
Start page 12
End page 21
Total pages 10
Place of publication Kidlington, Oxford, United Kingdom
Publisher Pergamon
Collection year 2014
Language eng
Subject 1500 Chemical Engineering
1600 Chemistry
2604 Applied Mathematics
2209 Industrial and Manufacturing Engineering
Abstract Proteins and peptides are emerging as components for novel materials that are switchable in response to their environment, and have enhanced sustainability over traditional materials. Proteins and peptides are known to be surface active and are widely used to stabilise foams and emulsions. However, designed surfactant proteins and peptides are presently produced using non-industrial processes based, for example, on costly chromatographic approaches developed for biopharmaceuticals. Here we report an intensified chromatography-free process for protein and peptide surfactant manufacture, for a recently-reported helix-bundle class of biosurfactants. The helix bundle structure is shown to remain stable and soluble under temperature and salt conditions that disrupt cells and precipitate cellular proteins. This finding opens a process route which simply involves heating cells, in fermentation media, to high temperature (e.g. 95°C), leading to release of soluble biosurfactant with simultaneous precipitation of contaminants. This "bake-to-break and precipitate" (BPP) process allows recovery of purified biosurfactant through simple thermal treatment followed by solid-liquid separation. Experiments were conducted with the four-helix bundle protein DAMP4, which was expressed intracellularly at a level of 15mgL-1 OD600 -1 in fully synthetic minimal media. Thermal treatment of 100mL of E. coli suspension at OD600=4 produced 4.8mg of functional protein surfactant at a yield of 84% following simple microfiltration. Further polishing by precipitation and filtration gave 2.4mg of highly-pure biosurfactant. This work demonstrates that co-considered molecular and intensified process design can be used to progress the development of new biological products into low-cost industrial sectors such as those based on surfactants.
Keyword Biosurfactant
Process intensification
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2014 Collection
Australian Institute for Bioengineering and Nanotechnology Publications
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Citation counts: TR Web of Science Citation Count  Cited 7 times in Thomson Reuters Web of Science Article | Citations
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