Enzymes for Modification of Chitin and Chitosan

Vaaje‐Kolstad, Gustav; Tuveng, Tina Rise; Mekasha, Sophanit; Eijsink, Vincent G. H.

doi:10.1002/9781119450467.ch8

Cited by 7 publications

(6 citation statements)

References 208 publications

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“…The biotechnological approach makes use of the increasing number of well-characterised, regio-selective chitin deacetylases and sequence-dependent chitosan hydrolases [ 49 – 55 ]. The latter can yield mixtures of chitosan oligomers with partially defined acetylation patterns, as the subsite preferences of the hydrolases determine the residues at and near the reducing and non-reducing ends of the oligomeric products.…”

Section: Three Advances Of Research In the Last Decadementioning

confidence: 99%

Deciphering the ChitoCode: fungal chitins and chitosans as functional biopolymers

Cord‐Landwehr

Moerschbacher

2021

Fungal Biol Biotechnol

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Chitins and chitosans are among the most widespread and versatile functional biopolymers, with interesting biological activities and superior material properties. While chitins are evolutionary ancient and present in many eukaryotes except for higher plants and mammals, the natural distribution of chitosans, i.e. extensively deacetylated derivatives of chitin, is more limited. Unequivocal evidence for its presence is only available for fungi where chitosans are produced from chitin by the action of chitin deacetylases. However, neither the structural details such as fraction and pattern of acetylation nor the physiological roles of natural chitosans are known at present. We hypothesise that the chitin deacetylases are generating chitins and chitosans with specific acetylation patterns and that these provide information for the interaction with specific chitin- and chitosan-binding proteins. These may be structural proteins involved in the assembly of the complex chitin- and chitosan-containing matrices such as fungal cell walls and insect cuticles, chitin- and chitosan-modifying and -degrading enzymes such as chitin deacetylases, chitinases, and chitosanases, but also chitin- and chitosan-recognising receptors of the innate immune systems of plants, animals, and humans. The acetylation pattern, thus, may constitute a kind of ‘ChitoCode’, and we are convinced that new in silico, in vitro, and in situ analytical tools as well as new synthetic methods of enzyme biotechnology and organic synthesis are currently offering an unprecedented opportunity to decipher this code. We anticipate a deeper understanding of the biology of chitin- and chitosan-containing matrices, including their synthesis, assembly, mineralisation, degradation, and perception. This in turn will improve chitin and chitosan biotechnology and the development of reliable chitin- and chitosan-based products and applications, e.g. in medicine and agriculture, food and feed sciences, as well as cosmetics and material sciences.

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Section: Three Advances Of Research In the Last Decadementioning

confidence: 99%

Deciphering the ChitoCode: fungal chitins and chitosans as functional biopolymers

Cord‐Landwehr

Moerschbacher

2021

Fungal Biol Biotechnol

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“…Enzymatic chitin degradation involves a synergistic interplay between different chitinolytic enzymes, such as lytic polysaccharide monooxygenases (LPMOs), chitinases, and β-Nacetylglucosaminidases. 9,[13][14][15] Streptomyces, the largest genus in the phylum Actinobacteria, is gram-positive and can degrade complex polysaccharides, including chitin and thus play a key role in the nature's carbon cycle. 16,17 In general, Streptomyces harbours genomes of larger size (>5 Mb), which encode a plethora of carbohydrate-active enzymes (CAZymes) for degradation of complex polysaccharides.…”

Section: Introductionmentioning

confidence: 99%

Improving efficiency and sustainability of chitin bioconversion through a combination of Streptomyces secretomes and mechanical-milling

Duhsaki

Mukherjee

Madhuprakash

2023

Preprint

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Chitin, particularly α-chitin, is the most abundant and highly recalcitrant form, fortified by an intricate network of hydrogen bonds. Efficient valorization of α-chitin requires a mild pre-treatment and enzymatic hydrolysis. Streptomyces spp. secrete chitin-active CAZymes that can efficiently tackle the recalcitrant problem of chitin biomass. To better understand the potential of Streptomyces spp., a comparative analysis was performed between the novel isolate, Streptomyces sp. UH6 and the well-known chitin degraders, S. coelicolor and S. griseus. Growth studies and FE-SEM analysis revealed that all three Streptomyces spp. could utilize and degrade both α- and β-chitin. Zymogram analysis showed expression of 5-7 chitinases in the secretomes of Streptomyces strains. The chitin-active-secretomes produced by Streptomyces sp. UH6 and S. griseus were optimally active at acidic pH (pH 4.0 and 5.0) and 50°C. Time-course degradation of α- and β-chitin with the secretomes generated N-acetyl-D-glucosamine (GlcNAc) and N,N-diacetylchitobiose [(GlcNAc)2] as the predominant products. Further, the highly crystalline α-chitin was subjected to pre-treatment by ball-milling, which reduced the crystallinity from 88% to 56.6% and increased the BET surface area by 3-folds. Of note, the activity of all three Streptomyces secretomes was improved by a mild pre-treatment, while Streptomyces sp. UH6 secretome displayed improved GlcNAc and (GlcNAc)2 yields by 14.4 and 9.6-folds, respectively. Overall, our results suggest that the Streptomyces chitin-active-secretomes, particularly Streptomyces sp. UH6, can be deployed for efficient valorization of chitin biomass and to establish an economically feasible and eco-friendly process for valorizing highly recalcitrant α-chitin.

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“…Enzymatic chitin degradation involves a synergistic interplay between different chiti-nolytic enzymes, such as lytic polysaccharide monooxygenases (LPMOs), chitinases, and β-N-acetylhexosaminidases. 13,[17][18][19] Streptomyces, the largest genus in the phylum actinobacteria, is Gram-positive and can degrade complex polysaccharides, including chitin and thus play a key role in the nature's carbon cycle. 20,21 In general, Streptomyces harbours genomes of larger size (>5 Mb), which encode a plethora of carbohydrate-active enzymes (CAZymes) for degradation of complex polysaccharides.…”

Section: Introductionmentioning

confidence: 99%

Improving the efficiency and sustainability of chitin bioconversion through a combination of Streptomyces chitin-active-secretomes and mechanical-milling

2023

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Enzymes for Modification of Chitin and Chitosan

Cited by 7 publications

References 208 publications

Deciphering the ChitoCode: fungal chitins and chitosans as functional biopolymers

Deciphering the ChitoCode: fungal chitins and chitosans as functional biopolymers

Improving efficiency and sustainability of chitin bioconversion through a combination of Streptomyces secretomes and mechanical-milling

Improving the efficiency and sustainability of chitin bioconversion through a combination of Streptomyces chitin-active-secretomes and mechanical-milling

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