Synthesis and techno-economic assessment of microbial-based processes for terpenes production

Abstract

BackgroundRecent advances in metabolic engineering enable the production of chemicals from sugars through microbial bio-conversion. Terpenes have attracted substantial attention due to their relatively high prices and wide applications in different industries. To this end, we synthesize and assess processes for microbial production of terpenes.ResultsTo explain a counterintuitive experimental phenomenon where terpenes such as limonene (normal boiling point 176 °C) are often found to be 100% present in the vapor phase after bio-conversion (operating at only ~ 30 °C), we first analyze the vapor–liquid equilibrium for systems containing terpenes. Then, we propose alternative production configurations, which are further studied, using limonene as an example, in several case studies. Next, we perform economic assessment of the alternative processes and identify the major cost components. Finally, we extend the assessment to account for different process parameters, terpene products, ways to address terpene toxicity (microbial engineering vs. solvent use), and cellulosic biomass as a feedstock. We identify the key cost drivers to be (1) feed glucose concentration (wt%), (2) product yield (% of maximum theoretical yield) and (3) VVM (Volume of air per Volume of broth liquid per Minute, i.e., aeration rate in min−1). The production of limonene, based on current experimental data, is found to be economically infeasible (production cost ~ 465 $/kg vs. market selling price ~ 7 $/kg), but higher glucose concentration and yield can lower the cost. Among 12 terpenes studied, limonene appears to be the most reasonable short-term target because of its large market size (~ 160 million $/year in the US) and the relatively easier to achieve break-even yield (~ 30%, assuming a 14 wt% feed glucose concentration and 0.1 min−1 VVM).ConclusionsThe methods proposed in this work are applicable to a range of terpenes as well as other extracellular insoluble chemicals with density lower than that of water, such as fatty acids. The results provide guidance for future research in metabolic engineering toward terpenes production in terms of setting targets for key design parameters.Electronic supplementary materialThe online version of this article (10.1186/s13068-018-1285-7) contains supplementary material, which is available to authorized users.

The Potential Production of the Bioactive Compound Pinene Using Whey Permeate

“…If the 10% of annual lactose produced from cheese production (860,000 metric tons) can be utilized in a similar manner as glucose, this would equate to 22,446 metric tons of pinene that could be produced a year. This represents approximately half of the current market for pinene [13]. The 2018 market size for αand β -pinene was approximately $56 and $102 million/year, respectively [13].…”

“…For dimerized pinene to be an economically viable fuel, a sustainable production method must be developed. The combined annual production volume of α and β-pinene is approximately 49 million liters [13]. This is several orders of magnitude less than what would be needed to make a tangible contribution to the jet fuel market, considering that U.S. airline carriers consumed 67 billion liters of jet fuel in 2016 [14].…”

“…A recent techno-economic assessment of microbial terpenoid production indicated that 80%-95% of the costs can be attributed to the cost of the feedstock [13]. Cane syrup is often utilized as the industrial feedstock for S. cerevisiae β-farnesene synthesis [25,45], but its cost is a current limitation to commercializing the microbial production of pinene due to lower titers [13]. Thus, the identification of an alternative low-cost feedstock for microbial pinene production could significantly improve the cost-effectiveness.…”

“…This represents approximately half of the current market for pinene [13]. The 2018 market size for αand β -pinene was approximately $56 and $102 million/year, respectively [13]. If the challenges of monoterpenoid production can be overcome and microbial production yields are similar to those of the microbially produced sesquiterpene, β-farnesene (17.3% g β-farnesene/g glucose) then this could equate to the production of 148,780 metric tons of pinene [25].…”

SILVER SULFATE (Ag2SO4): MOLECULAR ANALYSIS AND ION TRANSPORT

“…Densitas (146)(147)(148)(149) 2,61 g/cm 3(150) Titik didih (151)(152)(153)(154) Titik leleh (155)(156)(157)(158) 1.085 °C; 1.985 °F; 1.358 K (dekomposisi) 652 °C; 1.206 °F; 925 K Kelarutan dalam air (159-161) Dalam pelarut lain 0,79 gr/100 mL (20 °C) 1,30 gr/100 mL (80 °C) Larut dalam asam nitrat Tidak larut dalam etanol Struktur kristal (123,162,163) Ortorombik…”