Advances in application of aqueous two-phase system in separation and purification of active constituents from Chinese materia medica / 中草药

Aqueous two-phase system (ATPS) is a new liquid-liquid fractionation technique that has been extensively applied in the separation and purification of natural products including proteins, genetic material, bionanoparticles, cells, and secondary metabolites. Advantages of the technique include scale-up potential, continuous operation, ease of process integration, low toxicity, etc. This paper reviewed the applications in separation and purification of the active constituents from Chinese materia medica (CMM) in recent five years, so as to promote the development of separation of the active constituents in CMM.

Extraction of lipase from Burkholderia cepacia by PEG/Phosphate ATPS and its biochemical characterization

This work aimed to study the partitioning of a lipase produced by Burkholderia cepacia in PEG/Phosphate aqueous two phase system (ATPS) and its characterization. Lipase was produced by B. cepacia strains in a fermenter. Enzyme partitioning occurred at pH 6.0 and 8.0, using PEG 1500 and 6000 on two tie lines. Metal ions, pH and temperature effects on enzyme activity were evaluated. Five milliliter of 7.5% olive oil emulsion with 2.5% gumarabic in 0.1M sodium phosphate buffer at pH 8.0 and 37ºC were used for the activity determinations. Results showed that crude stratum from B. cepacia was partitioned by PEG1500/phosphate ATPS at pH 6.0 or 8.0 for, which the partitioning coefficients were 108-and 209-folds. Lipase presented optimal activity conditions at 37ºC and pH 8.0; it showed pH-stability for 4 h of incubation at different pH values at 37ºC. Metal ions such as Mn2+ , Co2+, I-and Ca2+ sustained enzymatic activities; however, it was inhibited by the presence of Fe2+, Hg2+ and Al3+ . Km and Vmax values were 0.258 U/mg and 43.90 g/L, respectively. A molecular weight of 33 kDa and an isoelectric point at pH 5.0 were determined by SDS-PAGE and IFS electrophoresis, respectively.

Produção e extração de ácido clavulânico de Streptomyces spp. por fermentação extrativa utilizando sistemas de duas fases aquo / Production and extraction of clavulanic acid from Streptomyces spp. by extractive fermentation using aqueous two-phase system

O ácido clavulânico (AC) é um potente inibidor de β-lactamases utilizado na área médica. Métodos alternativos, econômicos e simples para sua purificação são de grande interesse. Este trabalho objetivou produzir e extrair AC de Streptomyces spp. por fermentação extrativa utilizando sistema de duas fases aquosas (SDFA) - polietileno glicol (PEG)/sais fosfato. Foi selecionado o melhor produtor de AC entre sete linhagens de Streptomyces spp. Avaliou-se a influência de cinco fatores no cultivo do melhor produtor em frascos agitados (pH, temperatura, velocidade de agitação, concentrações das fontes de nitrogênio e de carbono), utilizando planejamento experimental estatístico. Definidas as melhores condições de cultivo, foram estudadas a produção e a extração do AC em fermentação extrativa utilizando SDFA em frascos agitados e em sistema descontínuo utilizando biorreator. Em biorreator também foram realizados o estudo termodinâmico do processo de fermentação nas condições ótimas obtidas nas etapas anteriores e a determinação do coeficiente volumétrico de transferência de massa (kLa), comparando os sistemas de fermentação no meio de cultivo simples (SF) e fermentação extrativa utilizando sistema SDFA PEG/sais fosfato (SFE) sem e com crescimento microbiano. A linhagem de Streptomyces selecionada como a melhor produtora de AC foi a DAUFPE 3060, a qual apresentou a maior produção desse inibidor, 494 mg/L em 48h, em frascos agitados nas condições: pH 6,0, 32ºC, 150 rpm, 5 g/L de glicerol e 20 g/L de farinha de soja. Após a etapa de otimização realizada para o estudo da temperatura e da concentração de farinha de soja, variáveis mais significativas no estudo de seleção, a temperatura e a concentração de farinha de soja ótimas, foram 32ºC e 40 g/L, respectivamente, com produção de 629 mg/L de AC em 48h. O estudo termodinâmico confirmou que a temperatura de 32ºC é a máxima de produção do AC; após esse valor, inicia-se, gradualmente, a degradação do AC...

Clavulanic acid (CA) is a potent inhibitor of β-lactamases used in the medical field. Alternative methods, economic and simple purification are of great interest. This PhD project aims to produce and extract clavulanic acid of Streptomyces spp. By extractive fermentation using aqueous two-phase system (ATPS) - Polyethylene glycol (PEG)/phosphate salts. The best producer of clavulanic acid among seven strains of Streptomyces spp was selected. The influence of five factors in the cultivation of the best producer in flasks (pH, temperature, agitation velocity, concentrations of nitrogen and carbon sources) using statistical experimental design was evaluated. Defined the best cultivation conditions, the production and extraction of clavulanic acid by extractive fermentation using ATPS in flasks and in a batch system using a bioreactor was analyzed. In batch system using a bioreactor were also carried out the thermodynamic study of the fermentation process in optimum conditions determined in previous steps and also determined the volumetric mass transfer coefficient (kLa) comparing the fermentation systems in simple culture medium (SF) and in a extractive fermentation using aqueous two-phase system (ATPS) PEG/phosphate salts (SEF) medium with and without microbial growth. A strain of Streptomyces spp. selected as the best producer of AC was DAUFPE 3060, which showed the highest production of this inhibitor, 494 mg/L at 48h, in flasks under the conditions of pH 6.0, 32 ºC, 150 rpm, 5 g/L of glycerol and 20 g/L of soybean flour. After the optimization step, the most significant variables in the study selection, temperature and concentration of soybean flour, were studied. The optimal values were 32 ºC and 40 g/L of temperature and soybean flour concentration, respectively, with production of 629 mg/L of CA after 48h of cultivation. The thermodynamic study confirmed that 32 ºC is the maximum temperature production of CA, after this value, starts…

The Application of Countercurrent Chromatography with Aqueous Two Phase System in the Separation of Proteins / 中国生物工程杂志

Aqueous two phase system(ATPS) provides a gentle, non-denaturing separation environment for proteins, enzymes. While high-speed countercurrent chromatography (HSCCC) is a liquid-liquid partition chromatography which uses centrifugal force to hold the stationary phase and facilities the mobile phase partitioning through the stationary phase, it can produce high separation efficiency with large sample loading capacity. However, the ordinary HSCCC apparatus (Type J ) fails to retention a satisfactory stationary phase of ATPS because of its high viscosity and low interfacial tension. Nevertheless, the later designed cross-axis planetary centrifuge system(X-CPC) can produce a greater lateral force field and enhances significantly the retention of the ATPS stationary phase. A review of the application of these CCC techniques with ATPS in the separation of proteins was given. Meanwhile, new techniques such as pH-peak focusing CCC and dye-ligand affinity CCC and some new CCC column design for improvement of separation efficiency and retention of ATPS stationary phase are introduced.