Xylose is a kind of pentose; its molecular formula is C 5 H 10 O 5 and its structural formula is shown in Fig. 6.2. Hemicellulose is a polysaccharide of d-xylose in nature. The industrial production of xylose has been gradually maturing. Xylose is often used as a food sweetener and is the source of xylitol.

The name xylose (Greek ξυλον, xylon meaning wood) originates from the isolation of the sugar from wood by Koch in 1886, and xylose is also known as wood sugar. Xylose is a pentose and can thus form both pentofuranosides and pentopyranosides, with the latter being the most common configurations (Fig. 1).

Xylose is the supreme and most attractive sugar obtained from hemicellulosic fraction of lignocellulosic biomass. Biological processes that use pentose-rich biomass as the sole carbon source will help to minimise raw material prices while also ensuring process sustainability.

The xylose isomerase converts the sugar into xylulose, which can be metabolized by the yeast. Once this was accomplished, oxygen-limited and anaerobic batch enrichment in the presence of high-xylose concentrations led to the selection of mutants that grew faster on xylose and eventually they ended up with a mutant that grew anaerobically on xylose.

Xylose fermentation by native S. cerevisiae is restricted by two major metabolic bottlenecks. The first bottleneck is the lack of xylose-specific transporters that compels extracellular xylose to be transported through native hexose transporters that have substantially higher affinities for hexoses than pentoses [73]. Consequently, xylose is ...

Mar 1, 2025 · Xylose is metabolized primarily through three distinct pathways: (i) the isomerase pathway, (ii) the oxidoreductase pathway, and (iii) the oxidative pathway. The xylose metabolic network is depicted in Fig. 1 (Domingues et al., 2021). The isomerase pathway is typically utilized by prokaryotes, such as E. coli, Bacillus sp., and Lactobacillus sp ...

Jun 18, 2024 · Xylose is the second most abundant sugar which is present in the lignocellulosic biomass. Xylose often comprises over 60 % of the hemicelluloses. Pentose sugar present in lignocellulosic biomass is very difficult to ferment as most of the microbes encompass hexose fermentation pathway, while only few microbes encompass pentose fermentation pathway.

Jun 1, 2021 · A typical xylose rich hydrolysate composition, as given in Table 3, is generated from different biomass types such as corn fiber, soy hulls, and bagasse (that are rich in xylose) in either a single-stage /two-stage hydrolysis [10], [11] to first extract arabinose and then xylose. To this hydrolysate, a boron reagent (e.g., PBA – phenylboronic ...

Mar 1, 2013 · The massic energy of combustion of the α-D-xylose sample was measured by using an isoperibol static bomb calorimeter, equipped with a twin-valve combustion bomb Type 1105, Parr Instrument Company, 1 with an internal volume of 0.340 dm 3 [4], [5].

Oct 1, 2024 · Further experiments using 13 C-labeled xylose should be conducted to confirm xylose uptake and metabolization, or to understand the xylose concentration decrease within the cultivation medium. A. protothecoides was the only candidate able to metabolize the three carbon sources when provided together and efficient growth was observed, lasting 2 ...