Sugars production from biomass

Luterbacher, J.S., Rand, J.M., Alonso, D.M., Han, J. et al. (2014) Nonen-zymatic sugar production from biomass using biomass-derived gamma-valerolactone. Science, 343, 277 -280. 

Within the framework of nonalimentary preparation of products from biomass, Loupy et al. prepared acetals of L-galactono-1,4-lactone (an important byproduct from the sugar beet industry) in excellent yields [32] by adsorbing the lactone and a long-chain aldehyde on montmorillonite KIO or KSF clay then exposing the reaction mixture to MW irradiation (Scheme 8.1). Improvements over the conventional method are substantial (DMF, H2SO4, 24 h at 40 °C, yields less than 20-25%). 

Rollin, J.A., Martin del Campo, J., Myung, S., Sun, F. et al. (2015) High-yield hydrogen production from biomass by in vitro metabolic engineering mixed sugars coutilization and kinetic modeling. 

In this process, sugars, obtained from biomass, are fermented at low pH into cis-muconic acid. The process of microbial muconic adic formation was already described by Frost and coworkers, who developed E. coli WNl/pWN2.248 that synthesized 36.8 g/L of c/s,ci>muconic acid in 22% (mol/mol) yield from glucose after 48 h of culturing under fed-batch fermentation conditions [147]. This strain did not possess the aroE encoded shikamate dehydrogenase preventing the cells to convert 3-dehydroshikimic acid into shikimic acid which is available for production of cis,cis-muconic acid. Optimization of microbial cis.m-muconic acid synthesis required expression of three enzymes not typically found in E. coli. A recent patent application by Bui et al. describes a productivity of 59 g/L cis muconic acid from 248 g/L glucose by a modified E. coli. in a 20 L fermenter in 88 h. 

The production of ethanol from sugar derived from starch and sucrose has been commercially dominated by the yeast S. cerevisiae (31). However, the sugar obtained from biomass is a mixture of hexoses and pentoses. Now, most wild-t5 e strains of S. cerevisiae do not metabolize xylose (13). 

From an ideal perspective, the application of biotechnology to chemicals production begins with biomass as a feedstock instead of petroleum. Glucose and other sugars derived from biomass serve as the chemical starting material in the fermentation of microbes that have been metabolically engineered, or otherwise selected to produce a desired chemical substance. Biochemical engineering techniques are then used to separate the chemical from the fermentation stream. For specific, limited chemical transformation steps, purified enzymes may take the place of microbes as biocatalysts. 

An early source of glycols was from hydrogenation of sugars obtained from formaldehyde condensation (18,19). Selectivities to ethylene glycol were low with a number of other glycols and polyols produced. Biomass continues to be evaluated as a feedstock for glycol production (20). 

The reliance of fossil fuels has been challenged by lower cost and renewable sources that are more environmentally friendly. The traditional chemical plant has met serious competition from green plants. Many monomers are now made via fermentation, using low-cost sugars as feedstock. Some of the commodity monomers are under siege by chemicals extracted from biomass. Monomer production has been expanded to include many more monomers from nature. 

Currently, ethanol is produced from sugar beets and from molasses. A typical yield is 72.5 liters of ethanol per ton of sugar cane. Modem crops yield 60 tons of sugar cane per hector of land. Production of ethanol from biomass is one way to reduce both the consumption of erode oil and environmental pollution. Domestic production and use of ethanol for fuel can decrease dependence on foreign oil, reduce trade deficits, create jobs in rural areas, reduce air pollution, and reduce global climate change carbon dioxide build-up. 

Spano, L.A., "Enzymatic Hydrolysis of Cellulosic Wastes to Fermentable Sugars for Alcohol Production", in "Symposium on Clean Fuels from Biomass, Sewage, Urban Refuse, Agricultural Wastes", 325-348, Inst, of Gas Technology, Chicago (1976). Wilke, C.R., Stockar, V. and Yang, R.D., AIChE Symposium Series No. 158, (1976) 104. 

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