Process analysis and economic evaluation for Poly(3-hydroxybutyrate) production by fermentation

Abstract

Several processes for the production and recovery of poly(3-hydroxybutyrate) (PHB) by Alcaligenes eutrophus, Alcaligenes latus, Methylobacterium organophilum, and recombinant Escherichia coli were designed based on the previously reported data and analyzed by computer-aided bioprocess design. PHB productivity, content, and yield signi®cantly affected the ®nal price of PHB. For the annual production of 2,850 tonnes of puri®ed PHB, the process employing A. eutrophus with the recovery method of surfactant-hypochlorite digestion resulted in lowest price of PHB, $ 5.58/kg. As the production scale increased to one million tonnes per year, the price of PHB dropped to $ 4.75/kg. The cost of carbon substrate signi®cantly affected the overall economics in large production scale. Therefore, the production cost can be considerably lowered when agricultural wastes, such as whey and molasses, are used.

Kinetic Analysis on Cell Growth and Biosynthesis of Poly (3-Hydroxybutyrate) (PHB) in Cupriavidus Necator H16

“…The highest CDW of 11.6 g/L was obtained at 55hr followed by highest PHB concentration of 8.6 g/L at 61.5hr. Based on the results obtained, the kinetic model for the experimental data was determined by using equations (1) to (6). The linear plot of equation (3) gives the values of µ m and x 0 which are presented in Table I.…”

“…2. From the calculated constants, the values for A(t) and B(t) in equation (6) can be calculated to give the theoretical PHB concentration values (Fig. 2).…”

“…Previous researches have proven that using substrate from pure glucose or sucrose can be rather expensive for large scale production. At USD 16/kg, the production cost of bioplastics from glucose would be 18 times higher than the conventional polypropylene plastics [6]. Since approximately 50% of PHA net production cost comes from the cost of its raw material [7], utilizing plant oil as the carbon source for PHA synthesis might reduce the PHA production cost and thus making large-scale PHA production a more feasible approach.…”

Hypochlorite digestion method for efficient recovery of PHB from Alcaligenes faecalis

“…1:1 mixture of ethanol and acetone give effi cient and high recovery yield of PHB over the earlier reported methods. Chloroform extraction method 0.63 [8] Dispersion method 1.1 [9] Hexane propanol method 1.92…”

“…The potential of PHB as biodegradable thermoplastic has been long recognized but the less effi cient recovery processes has hampered their commercialization for wide range of applications [7][8][9]. Time of extraction is equally important for the recovery of PHA, because during prolonged incubation under nutrient limiting conditions, PHB is utilized as a stored carbon and energy in presence of PHB depolymerase [10][11][12].…”