Effectiveness of xylose utilization for high yield production of lactate-enriched P(lactate-co-3-hydroxybutyrate) using a lactate-overproducing strain of Escherichia coli and an evolved lactate-polymerizing enzyme

Abstract

produced a copolymer having a higher LA fraction (34 mol%) than that grown on 6 glucose (26 mol%). This benefit of xylose was further enhanced by combining it with 7 an evolved LPE (ST/FS/QK), achieving a copolymer production having 60 mol% LA 8 from xylose, while glucose gave a 47 mol% LA under the same condition. The overall 9 carbon yields from the sugars to the polymer were similar for xylose and glucose, but

Simultaneous utilization of glucose and xylose via novel mechanisms in engineered Escherichia coli

“…This indicates that constitutive expression might not always be sufficient, and that additional optimization steps maybe required to engineer new metabolic pathways. Based on this and many other studies (Nduko et al, 2013;Utrilla et al, 2012;Zhou et al, 2012), one such step is evolutionary engineering. Genome sequencing is another, it being a powerful tool to characterize desirable phenotypes and provide a template for reverse engineering.…”

Biosynthesis, Properties, and Biodegradation of Lactate-Based Polymers

“…In a 2013 study, the application of xylose for the production of P(LA-co-3HB) was reported for the first time (35). The advantage of using of xylose for the production of P(LA-co-3HB) was justified by the higher cellular polymer content and LA fraction of the copolymer compared to the utilization of glucose.…”

“…In earlier studies using glucose, copolymers with LA fraction greater than 50 mol% were characterized with low polymer yields (less than 1 g/L) from 20 g/L glucose, limiting exploration of polymer properties (25). However, when using xylose, 7.3 g/L of P(60 mol% LA-co-3HB) was obtained, demonstrating the dual advantage of using xylose (35). To exploit the advantage of xylose, two distinct strategies were explored to improve LA fractions and polymer yields (36).…”

“…The use of glucose for the production of PHAs has been demonstrated to be efficient whereas, the use of xylose is known to be inefficient. In this report, methods for the efficient utilization of xylose were developed and enhanced to obtain high productivities of P(LA-co-3HB) with high LA fractions, which is critical in reducing the cost of producing LA-based polymers (35). Xylose utilization presented a new platform for the production of P(LA-co-3HB)s with LA fractions >50 mol% at high productivities, which will facilitate future exploration of material properties of LA-enriched P(LA-co-3HB)s, which was impossible with the use of glucose.…”

Rapid ethanol production at elevated temperatures by engineered thermotolerant Kluyveromyces marxianus via the NADP(H)-preferring xylose reductase-xylitol dehydrogenase pathway

“…D-Xylose is one of the main hydrolysis products of lignocellulosic biomass and is the second most abundant fermentable material. In contrast to the efficient glucose fermentation in yeast, xylose fermentation is challenging because only a few ethanolproducing microorganisms can readily ferment xylose, even though many microorganisms utilize xylose as a carbon source (Hu et al, 2011;Nduko et al, 2013;Zhang et al, 2013).…”