Production of natural and rare pentoses using microorganisms and their enzymes

Ahmed, Zakaria

doi:10.2225/vol4-issue2-fulltext-7

Cited by 64 publications

(40 citation statements)

References 39 publications

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“…For example, d-lyxose, d-arabinose, and d-talose can be used as startingm aterials for the synthesis of antitumor agents. [9] The d epimers of saccharides dominate in nature with the exception of l-arabinose, which is available from hemicelluloses. Consequently, l-arabinose can be used as as ubstrate for the synthesis of rare l-monosaccharides.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Isomerization of Biomass‐Derived Aldoses: A Review

Delidovich

Palkovits

2016

ChemSusChem

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Invited for this month's cover are Irina Delidovich and Regina Palkovits from RWTH Aachen University. The mini‐installation of sugar cubes and granulated sugar with chemical equations of isomerization reactions written on it represents a renewable feedstock for producing a broad range of valuable products. Our Review summarizes recent advances on chemocatalytic isomerization. The Review itself is available at 10.1002/cssc.201501577.

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Section: Introductionmentioning

confidence: 99%

Catalytic Isomerization of Biomass‐Derived Aldoses: A Review

Delidovich

Palkovits

2016

ChemSusChem

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“…This ketopentose has therefore been classified as a rare sugar (3). The markets and interest for rare and unnatural sugars have been growing, especially in the sweetener and pharmaceutical industries (40).…”

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confidence: 99%

“…The markets and interest for rare and unnatural sugars have been growing, especially in the sweetener and pharmaceutical industries (40). Microbial and enzymatic reactions are very suitable for converting D sugars to various L sugars (3).…”

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confidence: 99%

Metabolic Engineering of Lactobacillus plantarum for Production of l -Ribulose

Helanto¹,

Kiviharju²,

Leisola³

et al. 2007

Appl Environ Microbiol

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L-Ribulose is a rare and expensive sugar that can be used as a precursor for the production of other rare sugars of high market value such as L-ribose. In this work we describe a production process for L-ribulose using L-arabinose, a common component of polymers of lignocellulosic materials, as the starting material. A ribulokinase-deficient mutant of the heterofermentative lactic acid bacterium Lactobacillus plantarum NCIMB8826 was constructed. Expression of araA, which encodes the critical enzyme L-arabinose isomerase, was repressed by high glucose concentrations in batch cultivations. A fed-batch cultivation strategy was therefore used to maximize L-arabinose isomerase production during growth. Resting cells of the ribulokinasedeficient mutant were used for the production of L-ribulose. The isomerization of L-arabinose to L-ribulose was very unfavorable for L-ribulose formation. However, high L-ribulose yields were obtained by complexing the produced L-ribulose with borate. The process for L-ribulose production in borate buffer by resting cells was optimized using central composite designs. The experiment design suggested that the process has an optimal operation point around an L-arabinose concentration of 100 g liter ؊1 , a borate concentration of 500 mM, and a temperature of 48°C, where the statistical software predicted an initial L-ribulose production rate of 29.1 g liter ؊1 h ؊1 , a best-achievable process productivity of 14.8 g liter ؊1 h ؊1 , and a conversion of L-arabinose to L-ribulose of 0.70 mol mol ؊1 .Despite being a common metabolic intermediate in different organisms, L-ribulose is scarce in nature. This ketopentose has therefore been classified as a rare sugar (3). The markets and interest for rare and unnatural sugars have been growing, especially in the sweetener and pharmaceutical industries (40). Microbial and enzymatic reactions are very suitable for converting D sugars to various L sugars (3).Biotechnological L-ribulose production has been mainly investigated by using ribitol as the raw material. Most efficient L-ribulose production has been obtained by incubating ribitol in the presence of resting cells of acetic acid bacteria (4,14,29). The enzyme catalyzing the oxidation of ribitol to L-ribulose in these bacteria has been shown to be a membrane-bound NAD(P)-independent oxygenase (2). However, the volumes of production of ribitol are small, and it is expensive in pure form.Unlike other L sugars, L-arabinose is fairly abundant in nature. It is a common component of polymers of lignocellulosic materials (20). For example, sugar beet pulp, which is a byproduct of the sugar industry, has been reported to contain considerable amounts of L-arabinose (20%, wt/wt, of the deproteinated mass). L-Arabinose can easily be isolated from the pulp by acid or enzymatic hydrolysis, filtration, and acetone fractionation (41).The L form of ribulose is an intermediate in the pathway for L-arabinose utilization in many bacteria. The L-arabinose taken up by the cells is first isomerized to L-ribulose, which...

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“…The use of inexpensive raw substrates for the production of rare sugars is now attracting considerable attention. Previous studies confirmed the validity of this approach; for example, L-xylulose, D-tagatose, D-sorbose, Dpsicose, D-talitol, and allitol were successfully produced using microorganisms [7][8][9][10][11]. Among these, allitol is a rare hexitol that is synthesised by the reduction of D-psicose [12].…”

Section: Introductionmentioning

confidence: 62%