scholarly journals Basidiomycotic Yeast Cryptococcus diffluens Converts l-Galactonic Acid to the Compound on the Similar Metabolic Pathway in Ascomycetes

Fermentation ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 73
Author(s):  
Matsubara ◽  
Kataoka ◽  
Kishida
Keyword(s):  
Galacturonic Acid ◽  
High Performance ◽  
Chemical Properties ◽  
Value Added ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Conversion Process ◽  
Nuclear Magnetic Resonance Analysis ◽  
Resonance Analysis ◽  
Similar Chemical

(1) Background: It has been shown that d-galacturonic acid is converted to l-galactonic acid by the basidiomycotic yeast, Cryptococcus diffluens. However, two pathways are hypothesized for the l-galactonic acid conversion process in C. diffluens. One is similar to the conversion process of the filamentous fungi in d-galacturonic acid metabolism and another is the conversion process to l-ascorbic acid, reported in the related yeast, C. laurentii. It is necessary to determine which, if either, process occurs in C. diffluens in order to produce novel value-added products from d-galacturonic acid using yeast strains. (2) Methods: The diethylaminoethy (DEAE)-fractionated enzyme was prepared from the cell-free extract of C. diffluens by the DEAE column chromatography. The l-galactonic acid conversion activity was assayed using DEAE-fractionated enzyme and the converted product was detected and fractionated by high-performance anion-exchange chromatography. Then, the molecular structure was identified by nuclear magnetic resonance analysis. (3) Results: The product showed similar chemical properties to 2-keto-3-deoxy-l-galactonic acid (l-threo-3-deoxy-hexulosonic acid). (4) Conclusions: It is suggested that l-galactonic acid is converted to 2-keto-3-deoxy-l-galactonic acid by dehydratase in C. diffluens. The l-galactonic acid conversion process of C. diffluens is a prioritized pathway, similar to the pathway of ascomycetes.

scholarly journals Enzymatic Synthesis and Characterization of Different Families of Chitooligosaccharides and Their Bioactive Properties

2021 ◽  
Vol 11 (7) ◽  
pp. 3212
Author(s):  
Noa Miguez ◽  
Peter Kidibule ◽  
Paloma Santos-Moriano ◽  
Antonio O. Ballesteros ◽  
Maria Fernandez-Lobato ◽  
...  
Keyword(s):  
High Performance ◽  
Chemical Characterization ◽  
Amperometric Detection ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Enzymatic Production ◽  
Bioactive Properties ◽  
Substrate Properties ◽  
Chitin Hydrolysis

Chitooligosaccharides (COS) are homo- or hetero-oligomers of D-glucosamine (GlcN) and N-acetyl-D-glucosamine (GlcNAc) that can be obtained by chitosan or chitin hydrolysis. Their enzymatic production is preferred over other methodologies (physical, chemical, etc.) due to the mild conditions required, the fewer amounts of waste and its efficiency to control product composition. By properly selecting the enzyme (chitinase, chitosanase or nonspecific enzymes) and the substrate properties (degree of deacetylation, molecular weight, etc.), it is possible to direct the synthesis towards any of the three COS types: fully acetylated (faCOS), partially acetylated (paCOS) and fully deacetylated (fdCOS). In this article, we review the main strategies to steer the COS production towards a specific group. The chemical characterization of COS by advanced techniques, e.g., high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) and MALDI-TOF mass spectrometry, is critical for structure–function studies. The scaling of processes to synthesize specific COS mixtures is difficult due to the low solubility of chitin/chitosan, the heterogeneity of the reaction mixtures, and high amounts of salts. Enzyme immobilization can help to minimize such hurdles. The main bioactive properties of COS are herein reviewed. Finally, the anti-inflammatory activity of three COS mixtures was assayed in murine macrophages after stimulation with lipopolysaccharides.

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