Biosynthesis of a novel polysaccharide by Acetobacter xylinum

Shirai, Atsushi; Takahashi, Mikio; Kaneko, Hiroaki; Nishimura, Shin Ichiro; Ogawa, Masato; Nishi, Norio; Tokura, Seiichi

doi:10.1016/0141-8130(94)90059-0

Cited by 48 publications

(13 citation statements)

References 8 publications

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“…Therefore, cellulose with controllable crystallinity and degradability (in the human body) could be a next generation polymer for tissue engineering applications. Nonetheless the widespread presence of lysozyme in human body warrants its exploitation to degrade a biopolymer containing GlcNAc as one of its constituent [41], [42]. Since the cellulose synthase of G. xylinus can utilize both UDP-glucose and UDP-GlcNAc as substrate further genetic alteration can be carried out in G. xylinus to elevate the UDP-GlcNAc pool.…”

Section: Discussionmentioning

confidence: 99%

N-acetylglucosamine 6-Phosphate Deacetylase (nagA) Is Required for N-acetyl Glucosamine Assimilation in Gluconacetobacter xylinus

et al. 2011

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Metabolic pathways for amino sugars (N-acetylglucosamine; GlcNAc and glucosamine; Gln) are essential and remain largely conserved in all three kingdoms of life, i.e., microbes, plants and animals. Upon uptake, in the cytoplasm these amino sugars undergo phosphorylation by phosphokinases and subsequently deacetylation by the enzyme N-acetylglucosamine 6-phosphate deacetylase (nagA) to yield glucosamine-6-phosphate and acetate, the first committed step for both GlcNAc assimilation and amino-sugar-nucleotides biosynthesis. Here we report the cloning of a DNA fragment encoding a partial nagA gene and its implications with regard to amino sugar metabolism in the cellulose producing bacterium Glucoacetobacter xylinus (formally known as Acetobacter xylinum). For this purpose, nagA was disrupted by inserting tetracycline resistant gene (nagA::tetr; named as ΔnagA) via homologous recombination. When compared to glucose fed conditions, the UDP-GlcNAc synthesis and bacterial growth (due to lack of GlcNAc utilization) was completely inhibited in nagA mutants. Interestingly, that inhibition occured without compromising cellulose production efficiency and its molecular composition under GlcNAc fed conditions. We conclude that nagA plays an essential role for GlcNAc assimilation by G. xylinus thus is required for the growth and survival for the bacterium in presence of GlcNAc as carbon source. Additionally, G. xylinus appears to possess the same molecular machinery for UDP-GlcNAc biosynthesis from GlcNAc precursors as other related bacterial species.

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Section: Discussionmentioning

confidence: 99%

N-acetylglucosamine 6-Phosphate Deacetylase (nagA) Is Required for N-acetyl Glucosamine Assimilation in Gluconacetobacter xylinus

et al. 2011

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“…All of these known basic polysaccharides are homosaccharides. Microbial production of ␤-1,4-linked glucosaminoglucan by incorporating GlcNAc into cellulose has been attempted in expectation that the basic heteropolysaccharide should be as flexible as cellulose and as biocompatible as chitin/chitosan [35][36][37][38]. Gluconacetobacter xylinus, which is superior in cellulose secretion, was used by feeding N-acetylglucosamine to cells.…”

Section: Discussionmentioning

confidence: 99%

Presence of alternating glucosaminoglucan in the sheath of Thiothrix nivea

Takeda

Kondo

Yamada

et al. 2012

International Journal of Biological Macromolecules

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“…While the UDP-GlcNAc synthesis machinery already exists in this bacterium, it does not produce excess UDP-GlcNAc that would be accessible to the cellulose synthase. As a result, cellulose synthase of G. xylinus does not generally utilize UDP-GlcNAc as a substrate even though it has the potential to recognize this substrate (16,27).…”

Section: Discussionmentioning

confidence: 99%

“…To address the challenges associated with BC, prior efforts were made to modify the polymer based on chemical modifications or on feeding strategies, with limited success (16,27). It is our hypothesis that the most likely cause of the limitations to these studies was related to insufficient levels of UDP-charged nonglucose monomers available to the cellulose synthase.…”

mentioning

confidence: 99%

Novel In Vivo -Degradable Cellulose-Chitin Copolymer from Metabolically Engineered Gluconacetobacter xylinus

Yadav

Paniliatis

Shi

et al. 2010

Appl Environ Microbiol

113

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Despite excellent biocompatibility and mechanical properties, the poor in vitro and in vivo degradability of cellulose has limited its biomedical and biomass conversion applications. To address this issue, we report a metabolic engineering-based approach to the rational redesign of cellular metabolites to introduce N-acetylglucosamine (GlcNAc) residues into cellulosic biopolymers during de novo synthesis from Gluconacetobacter xylinus. The cellulose produced from these engineered cells (modified bacterial cellulose [MBC]) was evaluated and compared with cellulose produced from normal cells (bacterial cellulose [BC]). High GlcNAc content and lower crystallinity in MBC compared to BC make this a multifunctional bioengineered polymer susceptible to lysozyme, an enzyme widespread in the human body, and to rapid hydrolysis by cellulase, an enzyme commonly used in biomass conversion. Degradability in vivo was demonstrated in subcutaneous implants in mice, where modified cellulose was completely degraded within 20 days. We provide a new route toward the production of a family of tailorable modified cellulosic biopolymers that overcome the longstanding limitation associated with the poor degradability of cellulose for a wide range of potential applications.

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Biosynthesis of a novel polysaccharide by Acetobacter xylinum

Cited by 48 publications

References 8 publications

N-acetylglucosamine 6-Phosphate Deacetylase (nagA) Is Required for N-acetyl Glucosamine Assimilation in Gluconacetobacter xylinus

N-acetylglucosamine 6-Phosphate Deacetylase (nagA) Is Required for N-acetyl Glucosamine Assimilation in Gluconacetobacter xylinus

Presence of alternating glucosaminoglucan in the sheath of Thiothrix nivea

Novel In Vivo -Degradable Cellulose-Chitin Copolymer from Metabolically Engineered Gluconacetobacter xylinus

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