DOCSLIB.ORG

The Chitinolytic Cascade in Vibrios Is Regulated by Chitin Oligosaccharides and a Two-Component Chitin Catabolic Sensor͞kinase

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Chitinolytic Cascade in Vibrios Is Regulated by Chitin Oligosaccharides and a Two-Component Chitin Catabolic Sensor͞kinase The chitinolytic cascade in Vibrios is regulated by chitin oligosaccharides and a two-component chitin catabolic sensor͞kinase Xibing Li and Saul Roseman* Department of Biology, Johns Hopkins University, Baltimore, MD 21218 Contributed by Saul Roseman, November 19, 2003 Chitin, a highly insoluble polymer of GlcNAc, is produced in massive and structural proteins. These include at least one, and probably quantities in the marine environment. Fortunately for survival of several, extracellular chitinases, chemotaxis systems specific for aquatic ecosystems, chitin is rapidly catabolized by marine bacte- chitin oligosaccharides (highly potent chemoattractants), a ‘‘nu- ria. Here we describe a bacterial two-component hybrid sensor͞ trient sensor’’ that allows the cells to bind to the chitin as long kinase (of the ArcB type) that rigorously controls expression of Ϸ50 as the extracellular environment contains all ingredients neces- genes, many involved in chitin degradation. The sensor gene, chiS, sary for protein synthesis, a specific chitoporin in the outer was identified in Vibrio furnissii and Vibrio cholerae (predicted membrane, at least two hydrolases specific for chitin oligosac- amino acid sequences, full-length: 84% identical, 93% similar). charides in the periplasmic space that yield the monosaccharide Mutants of chiS grew normally on GlcNAc but did not express (GlcNAc) and the disaccharide (GlcNAc)2, respectively, three extracellular chitinase, a specific chitoporin, or ␤-hexosaminidases, transport complexes in the inner membrane, and a minimum of nor did they exhibit chemotaxis, transport, or growth on chitin six cytoplasmic enzymes that convert the products of transport oligosaccharides such as (GlcNAc)2. Expression of these systems to fructose-6-P, NH3, and acetate. We have reported the mo- requires three components: wild-type chiS; a periplasmic high- lecular cloning of 10 of these genes and characterized the affinity chitin oligosaccharide, (GlcNAc)n (n > 1), binding protein corresponding proteins (5–13). (CBP); and the environmental signal, (GlcNAc)n. Our data are Expression of the chitinolytic genes is rigorously regulated, consistent with the following model. In the uninduced state, CBP and the proposed mechanism for this regulation is shown in Fig. binds to the periplasmic domain of ChiS and ‘‘locks’’ it into the 1. The model comprises three components: (i) the environmen- minus conformation. The environmental signal, (GlcNAc)n, disso- tal signal, (GlcNAc)2, and possibly higher chitin oligosaccha- ciates the complex by binding to CBP, releasing ChiS, yielding the rides; (ii) a periplasmic solute binding protein specific for plus phenotype (expression of chitinolytic genes). In V. cholerae,a (GlcNAc) (n Ͼ 1) designated here as CBP for chitin oligo- cluster of 10 contiguous genes (VC0620–VC0611) apparently com- n saccharide binding protein; and (iii) a hybrid sensor kinase of prise a (GlcNAc) catabolic operon. CBP is encoded by the first, 2 the Arc B type (14), designated ChiS. In sensors of this kind, the VC0620, whereas VC0619–VC0616 encode a (GlcNAc) ABC-type 2 protein consists of a short N-terminal peptide chain in permease. Regulation of chiS requires expression of CBP but not the cytoplasm, a membrane domain, a periplasmic domain, a (GlcNAc) transport. (GlcNAc) is suggested to be essential for 2 n second membrane domain, and a long polypeptide chain extend- signaling these cells that chitin is in the microenvironment. ing into the cytoplasm. The latter comprises three subdomains: HK or His kinase, RR or receiver (aspartate), and HPt. The wo-component signal transduction systems (also known as phosphoryl group is transferred sequentially from ATP to HK, THis–Asp phosphorelay systems) play essential roles in trans- to RR, to a His in HPt, and finally to Asp in a separate ferring information from the environment to the respective cytoplasmic cognate response regulator that interacts with the genomes of prokaryotes and some eukaryotes (1, 2). There are genome (not shown in Fig. 1). at least 29 His kinase signal transduction systems in Escherichia We propose that repression of expression of the chitinolytic coli. In this article we report that two marine Vibrios, Vibrio genes, the minus phenotype, is the result of binding of the furnissii and Vibrio cholerae express a unique two-component (GlcNAc)n periplasmic binding protein to the periplasmic do- signaling system that stringently regulates expression of many main of the sensor, ‘‘locking’’ it into an inactive conformation genes required for chitin catabolism. ␤ (Fig. 1A). The environmental signals are chitin oligosaccharides Chitin is a highly insoluble ,1-4-linked polymer composed derived from partial hydrolysis of chitin by chitinases. In Fig. 1B, primarily of GlcNAc and some glucosamine (GlcN) residues and (GlcNAc) is used as the example because it is the major product is one of the most abundant organic substances in nature. More 2 formed by virtually all bacterial and many eukaryotic chitinases. than 1011 tons are estimated to be produced annually in marine In addition, two enzymes in the periplasmic space hydrolyze waters alone, mostly from copepods. The consumption of these higher oligosaccharides to (GlcNAc) and some GlcNAc (9, 10). huge quantities of chitin is critical for maintaining the C and N 2 CBP does not bind the monosaccharide, GlcNAc. cycles in these waters. It is, in fact, rapidly consumed. Early in the The extracellular signals, (GlcNAc) or, more generally, last century it was shown that ocean sediments contained only 2 (GlcNAc)n, compete with the sensor ChiS for CBP. ChiS cannot traces of chitin despite the constant rain of the polysaccharide ͞ (‘‘marine snow’’) to the ocean floor. This apparent enigma was bind the CBP (GlcNAc)n complex and is thereby activated to the resolved in 1937 when Zobell and Rittenberg (3) reported that plus phenotype (Fig. 1B), whereon the chitinolytic genes are many marine bacteria were chitinivorous, i.e., they could use expressed. chitin as the sole source of C and N, and it has since been shown that marine snow rarely reaches the ocean bottom but is de- Abbreviations: CBP, chitin oligosaccharide binding protein; PNP-GlcNAc, p-nitrophenyl graded as it slowly settles in the ocean waters. ␤-D-N-acetylglucosaminide. The degradation process is exceedingly complex (partially *To whom correspondence should be addressed at: Department of Biology, Mudd Hall, reviewed in ref. 4). The cells must sense the chitin, bind to it, and Johns Hopkins University, 33rd and Charles Streets, Baltimore, MD 21218. E-mail: degrade it to fructose-6-P, acetate, and NH3. We estimated that [email protected]. MICROBIOLOGY the overall chitin catabolic cascade involved dozens of enzymes © 2003 by The National Academy of Sciences of the USA www.pnas.org͞cgi͞doi͞10.1073͞pnas.0307645100 PNAS ͉ January 13, 2004 ͉ vol. 101 ͉ no. 2 ͉ 627–631 Downloaded by guest on September 28, 2021 induction of the ␤-hexosaminidases. The concentrations of antibiotics were 50 ␮g͞ml kanamycin and 75 ␮g͞ml ampicillin. Construction of Mutants. DNA preparation and analysis, restric- tion enzyme digests, ligation, and transformations were per- formed according to standard techniques (16). A Tn10 mutant library was constructed by transconjugation with V. furnissii strain ATCC 33813 as recipient and E. coli S17-1 harboring a suicide plasmid containing the Tn10 transposon with a chlor- amphenicol resistance gene derived from pNK2884 (17) as donor. The concentrations of antibiotics were 10 ␮g͞ml ampi- cillin and 30 ␮g͞ml chloramphenicol. V. cholerae deletion mutants were constructed by transconju- gation (18) with a temperature-sensitive suicide vector, pMAKSACA. V. cholera O1 E1 Tor N16961 strains with ⌬scrA⌬lacZ, KanR (VCXB21, wild type) or ⌬scrA⌬lacZ (VCXB36, wild type) were used as parental strains, and E. coli S17-1 cells harboring appropriate deletion vectors were used as donor strains. (i) CBP deletion strain: The EcoRI to SnaBI fragment of the cbp gene (VC0620) was deleted (373 of 556 aa; residues 43–416) and replaced with a kanamycin resistance cassette from plasmid pNK2859 (17). VCXB36 was used as the recipient strain. (ii) chiS deletion strain and chiS⌬cbp⌬ double- deletion strain: The chiS deletion strain contains fragments of the N and C termini of chiS, 48 and 50 bp, respectively, interrupted by a BglII restriction site. This construct was trans- ferred to VCXB21 as the recipient. The chiS⌬cbp⌬ double- deletion strain contains an additional AmpR (from pBR322) in ⌬ Fig. 1. Model for regulation of activity of the chitin catabolic sensor ChiS in the BglII site of the chiS deletion construct, using cbp as the V. furnissii and V. cholerae.(A) The minus phenotype. Three compartments, recipient. (iii) CBP-positive, permease deletion strain (VC0616– separated by two membranes are schematically illustrated: the extracellular VC0619⌬): The mutant contains 311 bp of the N terminus of space, the periplasmic space, and the cytoplasm. The outer membrane (OM) VC0619, a BglII site, followed by 329 bp at the C terminus contains the porins, including a chitin oligosaccharide specific porin (chito- of VC0616. A kanamycin resistance cassette from pNK2859 was porin). The periplasmic space contains the (GlcNAc)n high-affinity binding inserted into the BglII site. VCXB36 was used as the recipient protein (CBP) shown in pink. ChiS, the hybrid sensor, is green, and contains the strain. following domains: short amino terminal cytoplasmic domain, a periplasmic domain that separates two short membrane domains, and a large cytoplasmic ␤-Hexosaminidase Assay. domain comprising three subdomains: HK, the ATP-dependent, autophos- These enzymes were assayed with PNP- phorylatable His kinase͞phosphatase; RR, the Asp response regulator; and GlcNAc as described (10). In brief, V. cholerae cells were grown HPt, which contains a phosphorylatable His. The presumptive cognate recep- in the minimal lactate-ASW medium to mid-log phase, the cell 8 tor, a separate protein containing an active site Asp, is not shown. The inner density was adjusted to 5 ϫ 10 cells per ml, and the cells were ␮ ͞ membrane (IM) also contains the (GlcNAc)2 ABC type permease.
Load more

Recommended publications
  • Advances in Chitin/Chitosan Characterization and Applications
    Advances in Chitin/Chitosan Characterization and Applications Edited by Marguerite Rinaudo and Francisco M. Goycoolea Printed Edition of the Special Issue Published in Polymers www.mdpi.com/journal/polymers Advances in Chitin/Chitosan Characterization and Applications Advances in Chitin/Chitosan Characterization and Applications Special Issue Editors Marguerite Rinaudo Francisco M. Goycoolea MDPI • Basel • Beijing • Wuhan • Barcelona • Belgrade Special Issue Editors Marguerite Rinaudo Francisco M. Goycoolea University of Grenoble Alpes University of Leeds France UK Editorial Office MDPI St. Alban-Anlage 66 4052 Basel, Switzerland This is a reprint of articles from the Special Issue published online in the open access journal Polymers (ISSN 2073-4360) from 2017 to 2018 (available at: https://www.mdpi.com/journal/polymers/ special issues/chitin chitosan) For citation purposes, cite each article independently as indicated on the article page online and as indicated below: LastName, A.A.; LastName, B.B.; LastName, C.C. Article Title. Journal Name Year, Article Number, Page Range. ISBN 978-3-03897-802-2 (Pbk) ISBN 978-3-03897-803-9 (PDF) c 2019 by the authors. Articles in this book are Open Access and distributed under the Creative Commons Attribution (CC BY) license, which allows users to download, copy and build upon published articles, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. The book as a whole is distributed by MDPI under the terms and conditions of the Creative Commons license CC BY-NC-ND. Contents About the Special Issue Editors ..................................... ix Preface to ”Advances in Chitin/Chitosan Characterization and Applications” .........
    [Show full text]
  • Lactobacillus Plantarum ATCC 8014 Successive Two-Step Fermentation
    1 Production of chitin from shrimp shell powders using Serratia marcescens B742 and 2 Lactobacillus plantarum ATCC 8014 successive two-step fermentation 3 4 Hongcai Zhang a, Yafang Jin a, Yun Deng a, Danfeng Wang a, Yanyun Zhao a,b* 5 a School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, P.R. 6 China; 7 b Department of Food Science and Technology, Oregon State University, Corvallis 97331-6602, 8 USA 9 10 11 12 13 14 15 16 17 18 * Corresponding author: 19 Dr. Yanyun Zhao, Professor 20 Dept. of Food Science & Technology 21 Oregon State University 22 Corvallis, OR 97331-6602 23 E-mail: [email protected] 1 24 ABSTRACT 25 Shrimp shell powders (SSP) were fermented by successive two-step fermentation of Serratia 26 marcescens B742 and Lactobacillus plantarum ATCC 8014 to extract chitin. Taguchi 27 experimental design with orthogonal array was employed to investigate the most contributing 28 factors on each of the one-step fermentation first. The identified optimal fermentation conditions 29 for extracting chitin from SSP using S. marcescens B742 were 2% SSP, 2 h of sonication time, 30 10% incubation level and 4 d of culture time, while that of using L. plantarum ATCC 8014 31 fermentation was 2% SSP, 15% glucose, 10% incubation level and 2 d of culture time. 32 Successive two-step fermentation using identified optimal fermentation conditions resulted in 33 chitin yield of 18.9% with the final deproteinization (DP) and demineralization (DM) rate of 34 94.5% and 93.0%, respectively. The obtained chitin was compared with the commercial chitin 35 from SSP using scanning electron microscopy (SEM), Fourier transform infrared spectrometer 36 (FT-IR) and X-ray diffraction (XRD).
    [Show full text]
  • Immunostimulatory Properties and Antitumor Activities of Glucans (Review)
    INTERNATIONAL JOURNAL OF ONCOLOGY 43: 357-364, 2013 Immunostimulatory properties and antitumor activities of glucans (Review) LUCA VANNUCCI1,2, JIRI KRIZAN1, PETR SIMA1, DMITRY STAKHEEV1, FABIAN CAJA1, LENKA RAJSIGLOVA1, VRATISLAV HORAK2 and MUSTAFA SAIEH3 1Laboratory of Immunotherapy, Department of Immunology and Gnotobiology, Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i., 142 20 Prague 4; 2Laboratory of Tumour Biology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, v.v.i., 277 21 Libechov, Czech Republic; 3Department of Biology, University of Al-Jabal Al-Gharbi, Gharyan Campus, Libya Received April 5, 2013; Accepted May 17, 2013 DOI: 10.3892/ijo.2013.1974 Abstract. New foods and natural biological modulators have 1. Introduction recently become of scientific interest in the investigation of the value of traditional medical therapeutics. Glucans have Renewed interest has recently arisen for both functional foods an important part in this renewed interest. These fungal wall and the investigation of the scientific value of traditional components are claimed to be useful for various medical medical treatments. The evaluation of mushroom derivatives purposes and they are obtained from medicinal mushrooms and their medical properties are important part of these studies. commonly used in traditional Oriental medicine. The immu- Polysaccharides, including the glucans, have been described as notherapeutic properties of fungi extracts have been reported, biologically active molecules (1-4). Certain glucose polymers, including the enhancement of anticancer immunity responses. such as (1→3), (1→6)-β-glucans, were recently proposed as potent These properties are principally related to the stimulation of immunomodulation agents (3-5).
    [Show full text]
  • The Functional Aspects and Potential of Fungi Based Β-Glucan
    et International Journal on Emerging Technologies 11 (4): 435-445(2020) ISSN No. (Print): 0975-8364 ISSN No. (Online): 2249-3255 The Functional Aspects and Potential of Fungi Based β-Glucan Hendi Kuswendi 1, Eka Dwi Kusumawati 2 and Gemilang Lara Utama 3 1Student, Department of Food Industrial Technology, Faculty Agro-Industrial Technology, Universitas Padjadjaran, Sumedang, Indonesia. 2Student, Department of Food Industrial Technology, Faculty Agro-Industrial Technology, Universitas Padjadjaran, Sumedang, Indonesia. 3Assistant Professor, Department of Food Industrial Technology, Faculty Agro-Industrial Technology,Universitas Padjadjaran, Sumedang, Indonesia. (Corresponding author: Gemilang Lara Utama) (Received 25 May 2020, Revised 27 June 2020, Accepted 11 July 2020) (Published by Research Trend, Website: www.researchtrend.net) ABSTRACT: β-glucan is a natural polysaccharide derivatives composed of glucose monomers with β- glycoside bonds that can be synthesized by various microorganisms including fungi. So far, there have been many studies revealed that the main source of β-glucan production is cereal, yeast, and fungi. However, the study was more dominated by cereal and yeast as producer of β-glucan, therefore in this study will be explored the potential production of filamentous fungi based β-glucan. Rhizopus sp . and Aspergillus sp . are members of filamentous fungi genus that can be used as producer of β-glucans because they have cell walls which composed of polysaccharide components, especially glucans. β-glucans categorized as Generally Recognized As Safe (GRAS), FDA has recommended a daily consumption of 3 g β-glucan to achieve such health benefits. β-glucan can be consumed directly as food supplement or incorporated in a wheat, biscuit, bread, and beverage such as daily fruit drink.
    [Show full text]
  • Preparation of Cellulose/Chitin Blend Materials and Influence of Their
    sustainability Article Preparation of Cellulose/Chitin Blend Materials and Influence of Their Properties on Sorption of Heavy Metals Dao Zhou 1,*, Hongyu Wang 1 and Shenglian Guo 2 1 School of Civil Engineering, Wuhan University, Wuhan 430072, China; [email protected] 2 School of Hydraulic Engineering, Wuhan University, Wuhan 430072, China; [email protected] * Correspondence: [email protected] Abstract: A series of biodegradable cellulose/chitin materials (beads and membranes) were success- fully prepared by mixing cellulose with chitin in an NaOH/thiourea–water system and coagulation in a H2SO4 solution. The effects of chitin content on the materials’ mechanical properties, morphology, structure, and sorption ability for heavy metal ions (Pb2+, Cd2+, and Cu2+) were studied by tensile tests, scanning electron micrographs, Fourier transform infrared spectroscopy, and atomic absorption spectrophotometry. The results revealed that the cellulose/chitin blends exhibited relatively good mechanical properties, a homogeneous, microporous mesh structure, and the existence of strong hydrogen bonds between molecules of cellulose and chitin when the chitin content was less than 30 wt%, which indicated a good compatibility of the cellulose/chitin materials. Furthermore, in the same chitin content range, Pb2+, Cd2+, and Cu2+ can be adsorbed efficiently onto the cellulose/chitin beads at pH0 = 5, and the sorption capacity of the beads is more than that of chitin flakes. This shows that the hydrophilicity and microporous mesh structure of the blends are favorable for the kinetics of sorption. Preparation of environmentally friendly cellulose/chitin blend materials provides a simple and economical way to remove and recover heavy metals, showing a potential application of chitin Citation: Zhou, D.; Wang, H.; Guo, S.
    [Show full text]
  • Agaricus Bisporus By-Products As a Source of Chitin-Glucan Complex Enriched Dietary Fibre with Potential Bioactivity
    applied sciences Article Agaricus bisporus By-Products as a Source of Chitin-Glucan Complex Enriched Dietary Fibre with Potential Bioactivity Sara M. Fraga and Fernando M. Nunes * CQ-VR, Chemistry Research Centre—Vila Real, Food and Wine Chemistry Lab, Chemistry Department, Universidade de Trás-os-Montes e Alto Douro, Apartado 1013, 5000-801 Vila Real, Portugal; [email protected] * Correspondence: [email protected] Received: 24 February 2020; Accepted: 13 March 2020; Published: 25 March 2020 Featured Application: A novel, simple and environmentally friendly method was developed and optimize to produce a dietary fiber ingredient from Agaricus bisporus by-products, with suitable characteristics for food application and potential biological activity, as a mean for upgrading mushroom industry wastes. Abstract: Mushroom production generates large amounts of by-products whose disposal creates environmental problems. The high abundance of biological active non-starch polysaccharides in mushroom cell walls makes these by-products attractive for dietary fiber-based ingredient (DFI) production. Traditional methods of dietary fiber preparation didn’t allow to obtain a DFI with suitable chemical and functional properties. In this work a simple and environmentally friendly method was developed and optimized for DFI production using a central composite design with treatment time, hydrogen peroxide and sodium hydroxide concentration as factors and chemical composition, chromatic and functional properties as dependent variables. The chemical composition of the DFI was strongly influenced by the process parameters and its functional and color properties were dependent on its fiber and protein content, respectively. The method developed is simple, uses food grade and low-cost reagents and procedures yielding a DFI with white color, no odor and a high concentration of dietary fiber (>60%) with an identical sugar composition to the original mushroom fiber.
    [Show full text]
  • Β-Glucans, History, and the Present: Immunomodulatory Aspects and Mechanisms of Action
    Journal of Immunotoxicology ISSN: 1547-691X (Print) 1547-6901 (Online) Journal homepage: http://www.tandfonline.com/loi/iimt20 β-Glucans, History, and the Present: Immunomodulatory Aspects and Mechanisms of Action M. Novak & V. Vetvicka To cite this article: M. Novak & V. Vetvicka (2008) β-Glucans, History, and the Present: Immunomodulatory Aspects and Mechanisms of Action, Journal of Immunotoxicology, 5:1, 47-57, DOI: 10.1080/15476910802019045 To link to this article: https://doi.org/10.1080/15476910802019045 Published online: 09 Oct 2008. Submit your article to this journal Article views: 2885 Citing articles: 107 View citing articles Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=iimt20 Journal of Immunotoxicology, 5:47–57, 2008 Copyright c Informa Healthcare USA, Inc. ISSN: 1547-691X print / 1547-6901 online DOI: 10.1080/15476910802019045 REVIEW ARTICLE β-Glucans, History, and the Present: Immunomodulatory Aspects and Mechanisms of Action M. Novak Institute of Chemical Technology, Prague, Czech Republic V. Vetvicka Department of Pathology, University of Louisville, Louisville, Kentucky, USA similar or nearly identical immune reactions in macroorganisms, The present paper represents a comprehensive up-to-date can differ in origin as well as in their primary, secondary, or review of β-glucans, their chemical and biological properties, tertiary structures or their solubility in water or alkalies. Due and their role in immunological reactions. β-D-Glucans belong to these factors, numerous discrepancies can be found in the to a group of physiologically active compounds called biological literature. Some sources of β-glucans are listed in Table 1.
    [Show full text]
  • Potential of Bacterial Chitinolytic, Stenotrophomonas Maltophilia, In
    Jabeen et al. Egyptian Journal of Biological Pest Control (2018) 28:86 Egyptian Journal of https://doi.org/10.1186/s41938-018-0092-6 Biological Pest Control RESEARCH Open Access Potential of bacterial chitinolytic, Stenotrophomonas maltophilia, in biological control of termites Faiza Jabeen1*, Ali Hussain2, Maleeha Manzoor1, Tahira Younis1, Azhar Rasul1 and Javed Iqbal Qazi3 Abstract Termites are important pest of crops, trees, and household wooden installments. Two species Coptotermes heimi and Heterotermes indicola are the major species of termites that results in great economic loss in Asia including Pakistan. Chitinases have drawn interest because of their relevance as biological control of pests. The study was performed to screen chitinolytic bacteria from dead termites and to determine their chitinolytic activity in degrading chitin content of termites. Ten isolates were obtained forming clear zones on chitin-containing agar plates. One isolate (JF66) had the highest (3.3 mm) chitinolytic index. Based on sequence of 16S rRNA gene, the isolate was identified as Stenotrophomonas maltophilia with (99%) similarity under Accession number KC849451 (JF66), and DNA G + C content was found to be (54.17%). S. maltophilia (JF66) produces chitinases upto 1757.41 U/ ml at 30 °C and pH 6.0 employing diammonium phosphate as a nitrogen source. Chitinase gene was also extracted and gets sequenced that confirmed its presence. Whole culture and different concentrations of crude enzyme of the isolate were tested on the chitin covering of termites. Mortalities showed that crude enzyme of isolate could degrade chitin of both species of the termites C. heimi and H. indicola. Chitinase produced by S.
    [Show full text]
  • Solubility of Chitin: Solvents, Solution Behaviors and Their Related Mechanisms 111
    DOI: 10.5772/intechopen.71385 Provisional chapter Chapter 7 Solubility of Chitin: Solvents, Solution Behaviors and SolubilityTheir Related of Chitin: Mechanisms Solvents, Solution Behaviors and Their Related Mechanisms Jagadish C. Roy, Fabien Salaün, Stéphane Giraud, JagadishAda Ferri, C. Guoqiang Roy, Fabien Chen Salaün, and Jinping Stéphane Guan Giraud, AdaAdditional Ferri, information Guoqiang is available Chen at and the end Jinping of the chapter Guan Additional information is available at the end of the chapter http://dx.doi.org/10.5772/intechopen.71385 Abstract Chitin is a natural polysaccharides having a unique molecular arrangement of 2-(acetylamino)-2-deoxy-d-glucose, it possesses multifunctional properties and is suitable for various applications mainly in pharmaceutical, biomedical food, textiles and pack- aging fields. Therefore, being considered as a superior material for a sustainable future of industrial development, chitin perfectly meets up the demands with diversified func- tionalities in applications, excellent biocompatibility and biodegradability. Non-toxicity to human and environment (air, water and soil) is a great opportunity for this revolutionary, innovative and sustainable material. Moreover, antibacterial potency and low immuno- genicity of chitin have broadened the aspects of research and development on structure- function relationship toward biological tissues and activities. Despite abundance, low cost and availability, many experimental data from potential studies, reproducibility problems of chitin solubility measurement still limit the development of products and access to the market in large volume. Batch-to-batch variability, non-precise characterization and ran- domly distributed acetyl groups of chitin structure eventually results in a bad reproduc- ibility of chitin solubility. Therefore, the chapter aims to organize the information of chitin structure at molecular level and correlate solubility with chitin structure.
    [Show full text]
  • Structural Analysis of Glucans
    Review Article Page 1 of 14 Structural analysis of glucans Andriy Synytsya, Miroslav Novak Department of Carbohydrates and Cereals, Institute of Chemical Technology, Prague, Czech Republic Corresponding to: Andriy Synytsya. Department of Carbohydrates and Cereals, Institute of Chemical Technology, Technická 5, 166 28 Prague 6 Dejvice, Czech Republic. Email: [email protected]. Abstract: Glucans are most widespread polysaccharides in the nature. There is a large diversity in their molecular weight and configuration depending on the original source. According to the anomeric structure of glucose units it is possible to distinguish linear and branched α-, β- as well as mixed α,β-glucans with various glycoside bond positions and molecular masses. Isolation of glucans from raw sources needs removal of ballast compounds including proteins, lipids, polyphenols and other polysaccharides. Purity control of glucan fractions is necessary to evaluate the isolation and purification steps; more rigorous structural analyses of purified polysaccharides are required to clarify their structure. A set of spectroscopic, chemical and separation methods are used for this purpose. Among them, NMR spectroscopy is known as a powerful tool in structural analysis of glucans both in solution and in solid state. Along with chemolytic methods [methylation analysis (MA), periodate oxidation, partial chemical or enzymatic hydrolysis, etc.], correlation NMR experiments are able to determine the exact structure of tested polysaccharides. Vibration spectroscopic methods (FTIR, Raman) are sensitive to anomeric structure of glucans and can be used for purity control as well. Molecular weight distribution, homogeneity and branching of glucans can be estimated by size-exclusion chromatography (SEC), laser light scattering (LLS) and viscometry.
    [Show full text]
  • Characterization of Chitin Deacetylase from Mucor Rouxii
    Proc. Natl. Acad. Sci. USA Vol. 90, pp. 2564-2568, April 1993 Applied Biological Sciences Bioconversion of chitin to chitosan: Purification and characterization of chitin deacetylase from Mucor rouxii DIMITRIS KAFETZOPOULOS*t, AGGELIKI MARTINOU*t, AND VASSILIs BOURIOTIS*tt *Enzyme Technology Division, Institute of Molecular Biology and Biotechnology, P.O. Box 1515, Heraklion 711 10, Crete, Greece; and tDepartment of Biology, Division of Applied Biology and Biotechnology, University of Crete, P.O. Box 1470, Heraklion 711 10, Crete, Greece Communicated by Fotis C. Kafatos, December 18, 1992 ABSTRACT Chitin deacetylase, the enzyme that catalyzes tion of chitin substrates, we have purified chitin deacetylase the hydrolysis of acetamido groups of N-acetylglucosamine in to homogeneity from its best-characterized source, the di- chitin, has been purified to homogeneity from mycelial extracts morphic fungus Mucor rouxii, and further characterized it. of the fungus Mucor rouxii and further characterized. The enzyme exhibits a low pI (-3). Its apparent molecular mass was MATERIALS AND METHODS determined to be =75 kDa by sodium dodecyl sulfate/poly- Materials. Mucor rouxii (ATCC no. 24905) was obtained acrylamide gel electrophoresis and -80 kDa by size-exclusion from the American Type Culture Collection. Glycol chitosan, chromatography, suggesting that the enzyme exists as a mono- concanavalin A (type IV), and glass beads (425-600 ,m) were mer. Carbohydrate analysis of purified chitin deacetylase purchased from Sigma. [3H]Acetic anhydride was obtained revealed that the enzyme is a high-mannose glycoprotein and from DuPont/New England Nuclear. Enzymes and reagents that its carbohydrate content is -30% by weight. Chitin for acetic acid determination were purchased from Boeh- deacetylase is active on several chitinous substrates and chitin ringer Mannheim.
    [Show full text]
  • ENTOMO FARMS Chitin, Chitosan and Chitin-Oligosaccharide Assessment and Health Benefits By: Dr
    ENTOMO FARMS Chitin, Chitosan and Chitin-Oligosaccharide Assessment and Health Benefits By: Dr. Grace Liu PhD. Role of Fiber and Oligosaccharides in Human Health Fiber is an underappreciated component in both modern and ancestral diets, yet the gut microbiota and its vast implications for health have clearly emerged in the last 10-15 years as second generation sequencing technology illuminates the intricate relationships the intestinal microorganisms have with human health and disease. Prebiotics are defined as fiber that stimulate the growth and activity of advantageous microorganisms. From our first hours of life, prebiotic oligosaccharides in breast milk feed and nurture the gut flora of babies until weaning onto solid food. Without an immune system, babies receive immunoprotection from not only their mother’s immunoglobulins but also the prebiotic oligosaccharides which have properties that reduce and eliminate pathogens such as E. coli, Salmonella, Pseudomonas, and Shigella which are associated with infection and disease. Oligosaccharides are considered fiber 1because they are resistant to digestion, fail to be broken in the small intestines by human digestive enzymes, and do not feed the baby or host. Instead oligosaccharides nourish and stimulate gut bacteria. Our intestinal flora help us with many functions that fortify our health that we cannot live without such as: ● breakdowning food ● producing or assimilating vitamins and nutrients ● purging opportunistic pathogens ● boosting fat burning antioxidants like conjugated linoleic acid (CLA) ● secretion of targeted antimicrobial compounds that crowd out harmful yeasts and pathogenic flora ● reversal of intestinal permeability ● balancing and improving immunity against disease and cancer Prebiotic oligosaccharides are found abundantly in nature and food such as lentils, legumes, green leafy vegetables, agave cacti, and non-starchy vegetables such as sunchokes, onions, and yacon roots.
    [Show full text]