Liquid–liquid extraction of an extracellular alkaline protease from fermentation broth using aqueous two-phase and reversed micelles systems

Abstract

The study of recovery of an extracellular alkaline protease from fermentation broth produced by Norcadiopsis sp. was carried out with liquid-liquid extraction through sodium di-(2-ethylhexyl) sulphosuccinate/isooctane reversed micelles systems and aqueous two-phase systems (polyethylene glycol/potassium phosphate). The best conditions for extraction and back-extraction with the reversed micelles system was obtained at pH 9.0 and pH 5.0, respectively, showing a yield of protein of 6.16%, a specific activity of 4.10 U/ml and a purification factor of 1.80. The studies using aqueous two-phase systems of polyethylene glycol/potassium phosphate at pH 10.0 showed purification factors of 2 and 5, and protein yield of 11 and 4%, respectively, for polyethylene glycol 550/potassium phosphate and polyethylene glycol 8000/potassium phosphate. The results indicate that the aqueous two-phase systems are more attractive as a first step in the isolation and purification processes.

In situ recovery of 2,3-butanediol from fermentation by liquid–liquid extraction

“…In general, it was concluded from the experiments that liquid-liquid extraction can successfully be used for in situ recovery, which is in agreement with literature [2,[19][20][21]. Our Wnding conWrmed that increased productivity and no longer acetoin production.…”

Optimized extraction of a lectin from Crataeva tapia bark using AOT in isooctane reversed micelles

“…These results suggest that the increased percentage of protein transferred into a new aqueous phase when pH was increased from 5.5 to 7.0 was not due to higher lectin content but to other contaminant proteins. Similar purification factors of protein, 1.8 and 1.5, using micellar systems have been reported for an extracellular alkaline protease from fermentation broth [22] and for a xylanase from fermentation broth [24], respectively. The presence of butanol in the system permitted the back-extraction of lectin from a reversed micellar phase to an aqueous phase, as a consequence of a structural factor change of the micelles, corroborated by Liu et al [9], and Lee et al [21].…”

“…A small amount of alcohol added to an organic solution can improve the back-extraction behaviour of proteins depending on the concentration and alcohol species used [21]. For example, the presence of butanol in the system may change the water properties inside reversed micelles [22] and may affect protein-micelle interactions in a fundamental manner [23]. For this reason 5% butanol was used during back-extraction.…”

Extraction of fibrinolytic proteases from Streptomyces sp. DPUA1576 using PEG-phosphate aqueous two-phase systems

“…Several promising alternatives for purification of industrial enzymes, including precipitation, liquid-liquid extraction (e.g. aqueous two-phase extraction) and crystallization [49,50] have emerged to replace conventional methods like ammonium sulphate precipitation, chromatography, gel filtration and affinity chromatography or a combination of these techniques [51].…”