Crustacean Chitin Research Articles

Environmental Sustainability and Physicochemical Property Screening of Chitin and Chitin-Glucan from 22 Fungal Species.

Thanks to its biobased character with embedded biogenic carbon, chitin can aid in the transition to a sustainable circular economy by replacing fossil carbon from the geosphere. However, meeting current demands for material availability and environmental sustainability requires alternative methods limiting conventional chemical and energy-consuming chitin extraction from crustaceans. To assist future chitinous bioproduct development, this work analyzes the physicochemical properties and potential environmental sustainability of fungal chitin-glucan complexes. A conventional isolation procedure using sodium hydroxide, a weak acid, and short reaction times are applied to the fruiting body of 22 fungal species. Besides, the valorization of underutilized waste streams including Agaricus bisporus and Agaricus brunnescens stipes is investigated. The carbohydrate analysis renders chitin fractions in the range of 9.5-63.5 wt %, while yields vary from 4.2 to 29.9%, and the N-acetylation degree in found in between 53.0 and 98.7%. The sustainability of the process is analyzed using life cycle assessment (LCA), providing impact quantification for global warming potential, terrestrial acidification, freshwater eutrophication, and water use. With 87.5-589.3 kg·CO2-equiv per kilo, potentially lower global warming potential values in comparison to crustacean chitin are achieved. The crystallinity degree ranged from 28 to 78%, while the apparent chitin crystalline size (L020) is between 2.3 and 5.4 nm. Ten of the species yield α-chitin coexisting with semicrystalline glucans. Zwitterionic properties are observed in aqueous solutions, shifting from cationic to anionic at pH 4.5. With its renewable carbon content, fungal chitin is an environmentally sustainable alternative for high-value applications due to its balance of minimal treatment, low carbon footprint, material renewability, ease of isolation, thermal stability, zwitterionic behavior, biodegradability, and noncytotoxicity.

Crosslinked Chitosan Films Supplemented with Randia sp. Fruit Extract.

This work proposes the development of a polymer film made up of affordable components for its use as a healthcare material. Chitosan, itaconic acid, and Randia capitata fruit extract (Mexican variation) are the unique ingredients of this biomaterial prospect. Chitosan (from crustacean chitin) is crosslinked with itaconic acid, and in situ added R. capitata fruit extract in a one-pot reaction carried out in water as the sole solvent. Structurally, the film formed is an ionically crosslinked composite characterized by IR spectroscopy and thermal analysis (DSC and TGA); cell viability was also performed in vitro using fibroblasts BALB/3T3. Dry and swollen films were analyzed to determine affinity and stability in water. This chitosan-based hydrogel is designed as a wound dressing due to the combined properties of the chitosan with R. capitata fruit extract, which has potential as bioactive material due to its properties in epithelial regeneration.

Physicochemical Characteristics of Biochar from Waste Cricket Chitin (Acheta domesticus).

The properties of biochar (BC) from crustacean chitin are relatively well understood, while there are few studies on BC from insect chitin. This study presents the characterization and phytotoxic assessment of BC produced from crickets and cricket chitin. Cricket powder (BCCR) and cricket chitin (BCCH) were pyrolyzed at 500 °C and 700 °C. Physicochemical characteristics, N ad-/desorption, FTIR, were examined. SEM images were also performed. Regardless of the pyrolysis temperature, biochars were characterized by a densely "packed" solid surface/monolithic type with a non-porous structure (0.05-0.22 m2/g) and high content of N (9.4-11.8%). BCCHs showed a higher pH (12.2-12.4) compared to BCCR (8.7-10.8). Based on the XRD analysis, BCs were characterized by an amorphous carbon turbostratic structure and a randomly oriented graphitic-like micro-crystallite structure. FTIR spectra of BCs confirmed the presence of various O2 and N-functional groups on the BC surface. BCCHs added to soil at rates from 0.5 to 1.5% significantly reduced the germination of Lepidium sativum. Stimulation of root elongation was also observed in the case of BCCR500 1.0% and BCCR700 1.5%. Thermal degradation of cricket powder and cricket chitin promotes the formation of organic N-containing heterocyclic rings, which lead to the production of N-doped carbons with potential uses in energy storage and the contaminations sorption.

A Unique Crustacean-Based Chitin Platform to Reduce Self-Aggregation of Polysaccharide Nanofibers

Every year, over 8 million tons of crustacean shells are discarded. However, there exists an opportunity for valorizing the chitin and calcium carbonate part of the composition of the shells. Our study revealed crustacean chitin reduces self-aggregation effects. It was shown that crustacean-based nanofibers alone or added to cellulose offer unprecedented reductions in viscosity even after drying to produce foams impossible for cellulose. Polysaccharide nanofibers suffer from increased viscosity from strong hydrogen bonding addressed by the incorporation of crustacean-based nanofibers. The ability of the nanocomposite to overcome self-aggregation and collapse was attributed to organized chitin nanofiber morphology in the crustacean matrix. As a result of enhanced surface area from reduced fiber aggregation, the chitin/crustacean-cellulose blend was tested for a biomedical application requiring a high surface area: coagulation. Preliminary experiments showed the crustacean matrices, especially those containing calcium carbonate, induced blood clotting when 35 s. A materials platform is proposed for bio-based nanofiber production overcoming intractable and difficult-to-address self-aggregation effects associated with polysaccharides.

Comparative study on extraction and characterization of chitin and chitosan from prawn and crab species collected from local water bodies of Bhopal

Chitin is the main component in the exoskeleton of all Prawn and Crab species and it a biopolymer having the structure almost identical as that of cellulose. The current study focuses on the extraction and characterization of Chitin and chitosan from the exoskeleton of local Prawn and Crab species by sequence of chemical processes involving demineralization, deproteinization and deacetylation. Crustacean Chitin and chitosan having more biological value such as physiological, non¬-toxicity, bio-digestibility, compatibility, absorption etc. these biological value of chitosan depend on the quality parameters which is related to source of raw material. The obtained chitin was transformed into most useful soluble chitosan. The results obtained showed there is quite difference in the appearance (demineralization product), weight of chitin, percentage of chitin, product appearance and solubility of studied Prawn and crab species.

Determination of Carbohydrate Composition in Mealworm (Tenebrio molitor L.) Larvae and Characterization of Mealworm Chitin and Chitosan.

Mealworm (Tenebrio molitor L.) is a classic edible insect with high nutritional value for substituting meats from vertebrates. While interest in mealworms has increased, the determination of carbohydrate constituents of mealworms has been overlooked. Thus, the aim of the present study was to investigate the carbohydrate content and composition of mealworms. In addition, the characteristics of mealworm chitin were determined as these were the major components of mealworm carbohydrate. The crude carbohydrate content of mealworms was 11.5%, but the total soluble sugar content was only 30% of the total carbohydrate content, and fructose was identified as the most abundant free sugar in mealworms. Chitin derivatives were the key components of mealworm carbohydrate with a yield of 4.7%. In the scanning electron microscopy images, a lamellar structure with α-chitin configuration was observed, and mealworm chitosan showed multiple pores on its surface. The overall physical characteristics of mealworm chitin and chitosan were similar to those of the commercial products derived from crustaceans. However, mealworm chitin showed a significantly softer texture than crustacean chitin with superior anti-inflammatory effects. Hence, mealworm chitin and chitosan could be employed as novel resources with unique advantages in industries.

A study on structural comparisons of α-chitin extracted from marine crustacean shell waste

In the present study, chitin was extracted from marine crustacean shell waste (shrimp, crab, squilla and lobster) using traditional chemical methods (deproteinisation and demineralization) and its physicochemical and structural properties were characterized. The chitin content of crustacean shell waste ranged from 17.50% to 23.75% on a dry weight basis. The molecular weight analyses revealed that the crustacean chitin showed low molecular weight. The results of X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FT-IR), Energy dispersive X-ray analysis (EDAX), scanning electron microscopy (SEM) and thermogravimetry/differential thermal analysis (TG/DTA) confirmed that the α-chitins isolated from crustacean shell waste were similar to commercial crustacean chitin. The crystalline index value of the extracted chitin varied from 80.3% to 80.8%. The infrared spectroscopy analysis of the crustacean chitin exhibited two bands at around 1660 and 1620 cm−1. SEM analysis of the extracted chitin showed the nanofibre and nanopore structures. Additionally, thermal stability of the crustacean chitin was close to that of the commercial chitin. Therefore, the results of this study confirmed that the extracted chitin is in α-form.

Crustacean chitin nanomaterial as reinforcement for bio-based polymer

ABSTRACT In this study, chitin nanofibers with an average diameter of 80–100 nm were extracted from crab shell and used to reinforce bio-based polymer, polylactic acid (PLA). Solvent-casting and hot-compression moulding were used to fabricate chitin/PLA nanocomposite. Chitin nanofibers were first dispersed in PLA/chloroform mixture before the solvent was left to evaporate naturally, leaving behind chitin/PLA thin film composite. Thicker specimen of composite was produced by filling the dog-bone mould cavities with chloroform-free chitin/PLA film followed by compression moulding at 190°C and 25 bar. Tensile strength tests were performed to evaluate the mechanical properties of the nanocomposite at different chitin concentration loading. Increase in chitin nanofiber content up to 5 wt.% effectively improves the Young’s modulus (E) and tensile strength (σ) of the resulting nanocomposite, of which the highest improvement was found at 5% chitin loading (E = 1.3 GPa, σ = 24 MPa). This account for 13% Young’s modulus and 275% tensile strength improvement compared to neat PLA specimen (E = 1.15 GPa, σ = 6.4 MPa). Further addition of chitin nanofiber decreases the tensile strength performance of the nanocomposite because of chitin-chitin agglomeration, which leads to poor dispersion of the nanofibers within the PLA matrix.

The Potential of Insects as Alternative Sources of Chitin: An Overview on the Chemical Method of Extraction from Various Sources.

Chitin, being the second most abundant biopolymer after cellulose, has been gaining popularity since its initial discovery by Braconot in 1811. However, fundamental knowledge and literature on chitin and its derivatives from insects are difficult to obtain. The most common and sought-after sources of chitin are shellfish (especially crustaceans) and other aquatic invertebrates. The amount of shellfish available is obviously restricted by the amount of food waste that is allowed; hence, it is a limited resource. Therefore, insects are the best choices since, out of 1.3 million species in the world, 900,000 are insects, making them the most abundant species in the world. In this review, a total of 82 samples from shellfish—crustaceans and mollusks (n = 46), insects (n = 23), and others (n = 13)—have been collected and studied for their chemical extraction of chitin and its derivatives. The aim of this paper is to review the extraction method of chitin and chitosan for a comparison of the optimal demineralization and deproteinization processes, with a consideration of insects as alternative sources of chitin. The methods employed in this review are based on comprehensive bibliographic research. Based on previous data, the chitin and chitosan contents of insects in past studies favorably compare and compete with those of commercial chitin and chitosan—for example, 45% in Bombyx eri, 36.6% in Periostracum cicadae (cicada sloughs), and 26.2% in Chyrysomya megacephala. Therefore, according to the data reported by previous researchers, demonstrating comparable yield values to those of crustacean chitin and the great interest in insects as alternative sources, efforts towards comprehensive knowledge in this field are relevant.

Plastic to elastic: Fungi-derived composite nanopapers with tunable tensile properties

Fungal chitin is attracting commercial and academic interest as a cheap, renewable, easily isolated and abundant alternative to crustacean chitin. Being covalently decorated with β-glucan, fungal chitin exhibits a native nanocomposite architecture that varies in fibre diameter and chitin to β-glucan ratio from species to species, resulting in mechanical properties ranging from brittle, high tensile strength, plastic-like properties to very tough and elastomeric rubber-like tensile properties if processed into paper form. This study utilised a mild alkaline process to extract chitin-β-glucan complexes from tree bracket fungi (D. confragosa) and common mushrooms (A. bisporus), which were then combined in varying ratios and hot pressed to form engineered composite nanopapers with tunable tensile properties. Fruiting bodies of common mushrooms, with almost proportional contents of chitin and β-glucan, exhibited a nanofibrous architecture resulting in very high tensile strengths, far outperforming crustacean-derived chitin. These nanopapers could then be plasticised in a controlled fashion through addition of extract from tree bracket fungi, which contains large quantities of β-glucan, to produce composite nanopapers. The fungal chitin extracts were significantly more hydrophobic than crustacean chitin, suggesting potential as a coating agent for hydrophilic materials, such as cellulose. These remarkable and controllable characteristics make fungi-derived materials versatile for a wide range of applications, including coatings, membranes, packaging and paper.

Dual Extraction of Crustacean and Fungal Chitosan from a Single Mucor circinelloides Fermentation

Mucor circinelloides is a fungus that has been reported to produce ethanol, oil, protein, phosphate and glucosamine, depending on the available nutrients and cultivation conditions. Due to its ability to produce extracellular proteases, it is able to ferment polypeptides and amino acids broken down from various protein sources. In this study, we attempted to culture the Mucor circinelloides on waste substrates to deproteinize prawn shells for the extraction of chitin and subsequently extract chitosan from its fungal cell wall in a concurrent fermentation. The physio-chemical properties of the extracted crustacean chitin and fungal chitosan were determined by Fourier Transform Infrared Spectroscopy (FTIR) and Elemental Analysis (EA). We found that Mucor circinelloides grown on okara and coffee waste behaved as an excellent protease producer and successfully extracted chitin from prawn shells with a degree of deacetylation of 69.94% and 68.82%, respectively, comparable to commercial chitin (70.46%). The fungal chitosan extracted from the fermentation of Mucor circinelloides on red grape pomace substrate showed a degree of deacetylation of 61.05%, comparable to commercial chitosan (64.00%). Our results suggested feasibility of extracting chitosan from seafood waste-streams using cost-effective microbial fermentation.

Surface properties of chitin-glucan nanopapers from Agaricus bisporus

The structural component of fungal cell walls comprises of chitin covalently bonded to glucan; this constitutes a native composite material (chitin-glucan, CG) combining the strength of chitin and the toughness of glucan. It has a native nano-fibrous structure in contrast to nanocellulose, for which further nanofibrillation is required. Nanopapers can be manufactured from fungal chitin nanofibrils (FChNFs). FChNF nanopapers are potentially applicable in packaging films, composites, or membranes for water treatment due to their distinct surface properties inherited from the composition of chitin and glucan. Here, chitin-glucan nanofibrils were extracted from common mushroom (Agaricus bisporus) cell walls utilizing a mild isolation procedure to preserve the native quality of the chitin-glucan complex. These extracts were readily disintegrated into nanofibre dimensions by a low-energy mechanical blending, thus making the extract dispersion directly suitable for nanopaper preparation using a simple vacuum filtration process. Chitin-glucan nanopaper morphology, mechanical, chemical, and surface properties were studied and compared to chitin nanopapers of crustacean (Cancer pagurus) origin. It was found that fungal extract nanopapers had distinct physico-chemical surface properties, being more hydrophobic than crustacean chitin.

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Chitin Nanopaper from Mushroom Extract: Natural Composite of Nanofibers and Glucan from a Single Biobased Source

An isolation method with mild mechanical agitation and no acidic extraction step from a mushroom substrate resulted in chitin nanofibers (ChNFs) with large shares of retained glucans (50–65%). The subsequent chitin nanopapers exhibited exceptionally high tensile strengths of >200 MPa and moduli of ca. 7 GPa, which were largely attributed to the preserved glucans in the mixture, imparting a composite nature to the nanopapers. The isolation method for ChNFs is notably different from the conventional process with crustacean chitin sources that do not incorporate glucans and where an acidic extraction step for the removal of minerals must always be included

Agricultural by-product suitability for the production of chitinous composites and nanofibers utilising Trametes versicolor and Polyporus brumalis mycelial growth

Abstract Agricultural by-products can be upcycled into environmentally-sustainable, inexpensive chitinous materials and nanofibers derived from fungal mycelium for composites, cosmetics, pharmaceuticals and water treatment applications. This study determined the suitability of common agricultural by-products as medium for fungal growth. Growth was measured by quantifying ergosterol, a unique fungal product, in solid and liquid media. The results reveal that fungi grew less on rice hull, sugarcane bagasse and wheat straw agricultural by-products than on commercial wheat grains. However, the liquid agricultural by-product blackstrap molasses facilitated very high biomass production, outperforming the commonly used laboratory nutrient malt extract. Hyphal fusion, sheet formation and hyphal diameter metrics of fungi growing on each substrate were evaluated by SEM to assess suitability for chitin nanofiber production. Utilising these materials offers a cheap, renewable, easily-isolated, and abundant alternative to problematic crustacean chitin that when implemented on a large scale could rapidly upcycle low-value agricultural by-products into high-value chitinous materials.

Molecular Cloning and Phylogenetic Analysis of a Chitin Deacetylase Isolated from the Epidermis of the Red Snow Crab <i>Chionoecetes japonicas</i>

Chitin deacetylase (CDA; EC 3. 5. 1. 41) catalyzes the deacetylation of chitin. In this study, we successfully cloned and sequenced a chitin deacetylase gene from the red snow crab Chionoecetes japonicas. By using reverse transcription-polymerase chain reaction (RT-PCR) and 5' and 3' rapid amplification of cDNA ends, we obtained a 2141-bp amplicon containing a chitin deacetylase gene (CjCDA) from the epidermis of C. japonicas. The amplicon contains a 1575-bp open reading frame that is predicted to encode a 525-amino acid protein. The structure predicted from the deduced amino acid sequence included an N-terminal signal peptide, chitin-binding domain (CBD), low-density lipoprotein receptor class A domain (LDL-A), and catalytic domain. Comparative analysis of the deduced amino acid sequence of CjCDA revealed the highest homology (74%) to gastrolith protein 59 of Cherax quadricarinatus. We used RT-PCR to evaluate the expression of CjCDA in various tissues of C. japonicas, and we observed that CjCDA was expressed only in the epidermis. A phylogenetic analysis, using the amino acid sequences of CjCDA and other known chitin deacetylases, showed that CjCDA belonged to a group of crustacean chitin deacetylases. To our knowledge, this is the first study reporting the cDNA cloning of a chitin deacetylase from a crab.

Fabrication and Characterization of Fungal Chitosan-SAP Membranes for Hemostatic Application

Novel membranes were fabricated from fungal chitosan (Cs) and starch based super absorbent polymer (SAP) for hemostatic application. The commercial production of Cs through alkaline deacetylation of crustacean chitin includes many drawbacks. Fungal Cs production, by a more eco-compatible technique, has become an alternative source for the traditional one. In this study, the production of fungal Cs was executed in a bioreactor from the mycelia of Absidia coerulea. The maximum obtained fungal Cs was 0.55 g/L after 48 h. The fabrication of Cs-SAP membranes was approached subsequently using two methods, physical blend of two polymers, and Cs-SAP sub-layer. To evaluate the homeostatic effect of Cs – SAP membranes on blood, erythrocyte sedimentation test was conducted in vitro. Since increasing the Cs concentration from 0.5 to 2 % w/v in the fabricated Cs – SAP membranes, reduces the erythrocyte sedimentation time from 69.8 to 62.3 min, respectively, while increasing the concentration of SAP (0.12-0.5 % w/v) has less or no significant effect on erythrocyte sedimentation time. Sub-layered 2L8 membrane significantly reduced ESR (P< 0.05) by 22%, while physically blended 11B8 membrane diminished ESR by only 12% compared to the control. Furthermore, these membranes were investigated by FT-IR, SEM, tensile, antimicrobial activity and cytotoxicity. Chitosan-SAP membranes can be described as bio-membranes with a homogeneous matrix, stable structure and interesting mechanical properties, with great possibilities of utilization in hemostasis. Keywords: Biopolymers, fungal chitosan, hemostasis, mechanical properties, membranes, superabsorbent.

Anti-biofilm activity of low-molecular weight chitosan hydrogel against Candida species

Candida invasive infections have increased in frequency during the last decades. Such infections are often associated to medical indwelling devices like central venous catheter. The recurrent nature and difficulties in the treatment of these infections are often related to biofilm formation. The objective of this study was to investigate the anti-biofilm activity of low-molecular weight chitosan hydrogel (LMWCH), a natural biopolymer obtained from the N-deacylation of crustacean chitin, upon clinical relevant Candida species. The in vitro ability of LMWCH to impair biofilm formation and to disorganize a preformed biofilm was tested in polystyrene microplates and quantified by the semi quantitative XTT assay and by the crystal violet assay. LMWCH in vivo efficacy as a coating for medical indwelling devices was evaluated for the first time for Candida parapsilosis, using a mouse subcutaneous foreign body model using polyurethane catheter segments. Scanning electron microscopy was used to access biofilm architecture after LMWCH treatment. We found that LMWCH efficiently impaired biofilm formation of all Candida species, also promoting biofilm disaggregation. Most importantly, LMWCH was able to significantly inhibit biofilm formation by C. parapsilosis in an in vivo catheter mouse model. SEM images showed biofilm collapsed cells compatible with membrane damage, suggesting that this could be one of the possible mechanisms underlying biofilm impairment. LMWCH revealed to be a promising compound for treatment of candidiasis or its prevention through medical device coating.

Investigations on different Crustacean chitin from India

Investigations on different Crustacean chitin from India

Effect of crustacean chitin on the efficacy of plant growth promoting bacteria in the control of root infecting fungi of sunflower and chickpea

Soil amendment with crustacean chitin used alone or with &lt;em&gt;Pseudomonas aeruginosa Bacillus subtilis&lt;/em&gt; significantly (p&lt;0,05) reduced infection of &lt;em&gt;Rhizoctonia solani Fusarium solani&lt;/em&gt; on sunflower and &lt;em&gt;R.solani&lt;/em&gt; on chickpea. Crab chitin used alone or with &lt;em&gt;P.aeruginosa&lt;/em&gt; or &lt;em&gt;B.subtilis&lt;/em&gt; completely controlled the infection of &lt;em&gt;Macrophomina phaseolina&lt;/em&gt; on chickpea. Prawn or shrimp powder used 1% w/w of soil was found phytotoxic on chickpea but not on sunflower. Maximum fresh weight of shoot was produced by &lt;em&gt;P.aeruginosa&lt;/em&gt; used with shrimp powder in sunflower and with crab chitin in chickpea. &lt;em&gt;P.aeruginosa&lt;/em&gt; produced greater plant height in chickpea used with shrimp chitin.