Supercritical Fluid Disruption of Ralstonia eutropha for Poly(β‐hydroxybutyrate) Recovery

Abstract

A new method for disruption of Gram-negative bacterium Ralstonia eutropha by supercritical CO(2) for poly(beta-hydroxybutyrate) (PHB) recovery is proposed. The effects of different parameters such as exposure time, pressure, temperature, volume of methanol as a modifier, and culture history on cell disruption efficiency were investigated using Taguchi's statistical approach to determine optimum conditions. The optimum conditions for cell disruption and PHB recovery were as follows: exposure time, 100 min; pressure, 200 atm; temperature, 40 degrees C; volume of methanol, 0.2 mL. The cell culture time was less significant. At optimum conditions, the maximum efficiency of PHB recovery was found to be 89%. The proposed method is comparable with other recovery methods in terms of the percentage of PHB recovery, while it is environmentally more benign.

Recovery and purification of intracellular polyhydroxyalkanoates from recombinant Cupriavidus necator using water and ethanol

“…2). A higher recovery temperature is more suitable for cell disruption compared to the low one (Mattingly and Best 1971;Hejazi et al 2003). Therefore, effectiveness of the extraction process was improved when the temperature was increased from 4 to 30°C, since a possible mechanism of the water and ethanol extraction method for PHA recovery is through the cell wall breakage (refer to the section of ''Proposed mechanism of PHA recovery using halogen-free method'').…”

Isolation and recovery of microbial polyhydroxyalkanoates

“…Supercritical fluids (SCF) have emerged as a potential extraction technique in the areas of PHA recovery (Table 1) [49][50][51]. The unique physicochemical properties of SCF such as high density and low viscosities proposed them as suitable extraction solvents [49].…”

“…The unique physicochemical properties of SCF such as high density and low viscosities proposed them as suitable extraction solvents [49]. The advantages offered by SCF have led to its popularity (Table 3).…”

“…Supercritical-carbon dioxide (SC-CO 2 ) is the most predominantly used SCF due to its low toxicity and reactivity, moderate critical temperature and pressure (31°C and 73 atm), availability, low cost, and non-flammability [49]. By using this method, P(3HB) recovery of 89% from C. necator at 200 atm, 40°C and 0.2 ml of methanol was reported [49]. Besides, there is a patent literature which describes on the purification of biopolymers such as rubber from plant material using SCF [52].…”

Supercritical Fluid Application in Food and Bioprocess Technology

“…The effects of the main parameters such as P, T, and solvent density on solubility were determined at different T (35 -75°C) and P (12.2 -35.5) MPa. Hejazi et al (2003) reported the effects of process variables such as exposure time, P, T, volume of methanol as a modifier, and culture history on PHB recovery from suspended R. eutropha in buffer solution. In another report, Khosravi-Darani et al extended this work to obtain maximum recovery with minimum energy consumption (2004).…”