Crayfish Shell Research Articles

Efficient production of GlcNAc in an aqueous-organic system with a Chitinolyticbacter meiyuanensis SYBC-H1 mutant.

Shellfish waste is a primary source for making N-acetyl-D-glucosamine. Thus, establishing a high-efficiency and low-cost bioconversion method to produce N-acetyl-D-glucosamine directly from shellfish waste was promising. A mutant C81 was obtained from Chitinolyticbacter meiyuanensis SYBC-H1 via 60Co-γ irradiation. This mutant C81 showed the highest chitinase activity of 9.8 U/mL that was 85% higher than the parent strain. The mutant C81 exhibted improved antioxidant activities, including total antioxidant capacity, superoxide radical ability, and hydroxyl radical scavenging ability, compared to that of the parent strain. Four out of nine organic solvents increased the chitinase activity by 1.9%, 6.8%, 11.7%, and 15.8%, corresponding to methylbenzene, n-heptane, petroleum ether, and n-hexane, respectively. The biphase system composed of aqueous and hexane presented a five-fold reduction of cell viability compared to the control. Using a continuous fermentation bioconversion process, 4.2g/L GlcNAc was produced from crayfish shell powder with a yield of 80% of the chitin content. This study demonstrated that the mutant C81 is suitable for converting crayfish shell powder into GlcNAc in an aqueous-organic system.

Synchronous removal of Cr(VI) and phosphates by a novel crayfish shell biochar-Fe composite from aqueous solution: Reactivity and mechanism

Nowadays, a great increasing attention has been paid to the coexistence of multiple inorganic pollutants in the environment. In this study, a novel crayfish shell biochar-Fe composite (FXB) was successfully produced and effectively used for the synchronous removal of Cr(VI) and phosphates (P) from aqueous solution. Experimental results revealed that FXB exhibited a high performance on the removal of Cr(VI) and P over a broader pH range. The escalating ionic strength and anions like Cl- and NO3- showed varying degrees of inhibition effects on Cr(VI) and P removal. The kinetic model of both Cr(VI) and P adsorption fit better with the pseudo-second-order model compared with the pseudo-first-order model. The isotherm of Cr(VI) fit well with the Langmuir model, whereas that of P adsorption fit well with the Freundlich model. Elovich model suggests that both Cr(VI) and P adsorption were the heterogeneous and multi-mechanism processes, and the intra-particle diffusion model confirms that these adsorption processes were dominated by surface and intra-particle diffusion reactions. Both Cr(VI) and P adsorption onto FXB were the spontaneous and endothermic nature. The synchronous removal of Cr(VI) and P could be efficiently achieved using this FXB composite under the certain conditions. A possible reaction mechanism for the synchronous adsorption of Cr(VI) and P onto FXB involving the synergistic effects of surface adsorption, precipitation, reduction and complexation processes was proposed.

Mitigation of organic fouling of ultrafiltration membrane by high-temperature crayfish shell biochar: Performance and mechanisms

The paper applied crayfish shell (CFS) biochar to the mitigation of ultrafiltration (UF) membrane fouling induced by humic acid (HA) and sodium alginate (SA). Results indicated that the high adsorption capacity of CFS800 to HA made it effective in alleviating the irreversible membrane fouling induced by HA, and the cross-linking reaction between the hydroxyl calcium components on CFS800 and SA reduced the reversible membrane fouling induced by SA rapidly. Further analysis showed that the “hydrogel flocs” generated by the cross-linking reaction would accumulate on the surface of the substrate membrane and form an amorphous hydrogel layer to intercept the subsequent foulant and purify the water quality further. Meanwhile, the mitigation performance of CFS800 was twice more than that of commercial powder activated carbon (PAC), and the dosage was the main factor affecting its practical application performance and thus could be considered as a promising material in alleviating membrane fouling induced by HA and SA. More importantly, the findings of the present study gave a new sight towards the application of biochar.

Synthesis and Evaluation of the Antidiabetic Potentials of Chitosan Combinations with Metformin and Momordica Balsamina Leaf Extract in Alloxan-Induced Diabetic Rats

Chitosan, a carbohydrate biopolymer, is medically gaining attention as a dietary supplement and a drug beneficial for improving blood glycemia, impaired glucose tolerance and altered lipid metabolism. Largely obtained from crustaceans, chitosan is also a promising vehicle used to deliver anti-diabetic drugs in implantable as well as injectable and oral routes. The present study is therefore aimed to synthesize chitosan and evaluate its antidiabetic potentials in combination with metformin and/or methanolic leaf extract of Momordica balsamina (MBM) in alloxan-induced diabetic rats. Chitosan was synthesized from crayfish shell through demineralization, deproteinization, deacetylation, and decolouration of the produced chitin. In the present study, a simple and an inexpensive acid-base titrimetric method was used for the determination of degree of deacetylation while the physicochemical properties; moisture content and ash content were determined using standard procedures.The efficacy of the drug binary systems of chitosan-metformin and chitosan-MBM were evaluated on the glucose tolerance of Wistar Albino rats made diabetic by a single interperitoneal injection of alloxan monohydrate (150 mg/kg body weight). The oral administration of both drug binary systems and chitosan exerted a significant (p<0.05) improvement on carbohydrate metabolism via glucose tolerance test when compared to the untreated diabetic rats. The blood glucose level of the chitosan group returned to near normal level 2 hours post-porandially, while chitosan-MBM, chitosanmetformin and metformin groups returned to their initial values only after 4 hours. Our findings are suggestive of the fact that chitosan-based drug binary systems possess anti-hyperglycemic activities and thus the potential to improve the pharmacokinetic and pharmacological profile of oral hypoglycemic drugs/herbs. Our findings could serve as basis for the development of novel antidiabetic drug systems.
 Keywords: Antidiabetic, Chitosan, Metformin, Methanolic extract, Momordica balsamina

ISOLATION AND CHARACTERIZATION OF CHITOSAN FROM SEA AND FRESHWATER WASTE, NORTH SUMATERA PROVINCE, INDONESIA

This study aims to manage shell and shell waste from fishery products into chitosan. The processing was carried out by isolating and characterizing chitosan from the shells of vaname shrimp (Litopenaeus vanname), the shells of the coral crab (Charybdis ferryatus) and the shells of the freshwater lobster (Cherax quadricarinatus). The isolation method was carried out in several stages starting with demineralization, deproteination, depigmentation, deacetylation and then the characterization of the isolated chitosan. Characterization includes determining the degree of deacetylation, yield percentage, and absorption analysis of the isolated chitosan functional group using Fourier Transform Infrared (FT-IR) spectrophotometry. The isolation results obtained chitosan from vaname shrimp shell waste, coral crab shells and freshwater crayfish shells with a degree of deacetylation (%) of 82.84±0.13; 82.84±0.13; and 67.84±0.05. Chitosan from the isolation of vaname shrimp shell waste, coral crab shells is in accordance with the Standard National Indonesian (SNI) quality, while chitosan from freshwater crayfish shell waste is not suitable

Purification and Characterisation of Two Novel Pigment Proteins from the Carapace of Red Swamp Crayfish (Procambarus clarkii)

Pigment proteins play a vital role in the red colour change of the red swamp crayfish (Procambarus clarkii) shell after cooking. In this study, two red-change-related pigment proteins with molecular weights of approximately 170 and 43 kDa—denoted as F1 and F2, respectively—were purified by ammonium sulphate salting-out and size exclusion chromatography. F1 and F2 entirely comprised homomultimeric protein complexes composed of 21 kDa subunits. LC-MS/MS analysis showed that the 21 kDa protein subunit belonged to the crustacyanin family, named P. clarkii crustacyanin A2 (PcCRA2). The full-length cDNA of PcCRA2 was cloned, which encoded 190 amino acid residues and was highly homologous (91.58%) with Cherax quadricarinatus crustacyanin A. The predicted 3D structure showed that PcCRA2 had a β-barrel structure for pigment encapsulation. The colour change of F1 was first detected at 40 °C, and the red change occurred upon heating above 60 °C. Additionally, with increasing temperature, its β-sheet content increased, and its α-helix content reduced. Correlation analysis showed that the redness value of F1 was significantly related to the heating temperature and the β-sheet content.

Enhanced Dissolution of Chitin Using Acidic Deep Eutectic Solvents: A Sustainable and Simple Approach to Extract Chitin from Crayfish shell Wastes as Alternative Feedstocks

Enhanced Dissolution of Chitin Using Acidic Deep Eutectic Solvents: A Sustainable and Simple Approach to Extract Chitin from Crayfish shell Wastes as Alternative Feedstocks

Influence of Dietary Replacement of Fish Meal with Crayfish Shell Meal on the Skin Coloration, Muscle Texture, and Amino Acid Composition of Oujiang Color Common Carp Cyprinus carpio var. color

AbstractAn 8‐week feeding trial was conducted to investigate the influence of dietary replacement of fish meal with crayfish shell meal (red swamp crayfish Procambarus clarkii) on the skin coloration, muscle texture, and amino acid composition of Oujiang color common carp Cyprinus carpio var. color. One‐hundred‐eighty fish with average initial weight of 3.0 ± 0.5 g were fed with two isonitrogenous and isolipidic diets (a control diet and a crayfish shell meal diet with 25% substitution of fish meal protein [CSM25]). At the termination of the feeding trial, there were no significant differences between the two groups in terms of lightness (L*), redness (a*), and yellowness (b*) values. Interestingly, one unexpected finding was the extent to which the highest value for total color difference (ΔE) was observed in caudal skin. The springiness, adhesiveness, cohesiveness, gumminess, and chewiness of the muscle were not affected by the CSM25 diet in this study. Muscle hardness was decreased by dietary supplementation with crayfish shell meal, although this decrease was not significant. Notably, there were significant increases in the levels of threonine, leucine, and lysine in the CSM25 group. The current results indicate that crayfish shell meal can alter some essential amino acid levels in muscle. These findings might help others to better understand the influence of dietary replacement of fish meal with crayfish shell meal on skin coloration, muscle texture, and amino acid composition.

Highly adsorptive pristine and magnetic biochars prepared from crayfish shell for removal of Cu(II) and Pb(II)

BackgroundBiochar has attracted considerable attention as a low-cost adsorbent comprised of carbon matrix and mineral for treatment of wastewater. The main purpose of this work was to manufacture CaCO3-rich biochars using crayfish shell as feedstock for removal of Cu(II) and Pb(II) from aqueous solution. MethodsPristine and magnetic biochars were prepared via direct pyrolysis and K2FeO4-promoted pyrolysis, respectively, and characterized by element analysis, BET, FTIR, SEM-EDS, XRD and XPS. Moreover, their adsorption capabilities toward Cu(II) and Pb(II) were investigated in aqueous solution. FindingsA large amount of CaCO3 was assembled on the pristine biochar pyrolyzed at 600 °C, leading to 715.10 mg/g and 1682.87 mg/g adsorption capacities for Cu(II) and Pb(II), respectively. Whereas, CaCO3 and single phase Fe3O4 were simultaneously introduced into the magnetic biochar with K2FeO4-promoted pyrolysis at 600 °C using 1/1 (g/g) ratio of K2FeO4 to crayfish shell, where 417.05 mg/g and 974.10 mg/g maximum adsorption capabilities were obtained for Cu(II) and Pb(II) with 29.66 emu/g saturation magnetism, respectively. Cu(II) and Pb(II) were mainly adsorbed onto the biochars as carbonates and oxides by their interaction with CaCO3 and carbon matrix.

Crayfish shell-based micro-mesoporous activated carbon: Insight into preparation and gaseous benzene adsorption mechanism

The preparation of hierarchically porous carbon via a low-cost way for gaseous benzene adsorption remains a challenge that needs to be addressed urgently. In this study, crayfish shell from kitchen garbage was employed as the precursor for synthesis of activated carbon (AC) via chemical activation strategy, which could be potential in synthesis because of the cost-effective precursor and simple way. Orthogonal design test and various characterization techniques were adopted to explore the optimal preparation conditions of AC. As a result, AC7 with the large specific surface area (2669.40 m2/g) and well-developed pore volume (1.42 cm3/g) has been synthesized successfully. Compared with other adsorbents, AC7 exhibited more excellent adsorption performance for gaseous benzene (684.6 mg/g) in the dynamic adsorption experiments. The influences of preparation factors by the range analysis method and environmental conditions via the single factor method on the adsorption performance of AC7 for gaseous benzene were investigated and analyzed, comprehensively. Based on the isotherm and thermodynamic models, the adsorption experiment data were fitted, analyzed and evaluated to figure out the adsorption mechanism. The results showed that the adsorption process was exothermic, and mainly physical. The partition coefficient and breakthrough volume were also applied to evaluate the benzene adsorption performance objectively. In addition, the reusability tests were carried out. In the eleventh cycle, the adsorption capacities under different initial concentrations were higher than 96.92% of the initial adsorption capacities, showing that AC7 possessed the good reusability. These results showed that AC7 would be an attractive and potential adsorbent for the gaseous benzene adsorption.

Using waste crayfish shell derived catalyst to synthesize glycerol carbonate by transesterification reaction between glycerol and dimethyl carbonate

Waste crayfish shell powder was utilized to prepare a series of solid base catalyst for the transesterification of glycerol with dimethyl carbonate to synthesize glycerol carbonate. Thermal decomposition behavior of waste crayfish shell powder was investigated by thermogravimetric analysis (TGA) and the different catalysts prepared at different calcinations temperature were characterized using FESEM, XRD, FTIR, BET techniques. It was clearly confirmed that the catalyst generated by the calcination of waste crayfish shell at 800 °C exhibited excellent catalytic activity, 98.7% glycerol conversion and 95.3% glycerol carbonate yield were obtained under mild reaction conditions such as 90 min of reaction time, 1:6 molar ratio of glycerol to dimethyl carbonate, 4 wt% of catalyst loading and 75 °C of reaction temperature.

Enhanced adsorption for the removal of tetracycline hydrochloride (TC) using ball-milled biochar derived from crayfish shell

Tetracycline hydrochloride (TC) is a broad-spectrum antibacterial widely used in the livestock and aquaculture industry. Entry of these into water body can bring serious threat to human health and it is difficult to degrade or remove by biodegradation due to bacterial resistance. Hence, non-biodegradation methods such as adsorption show advantages in TC treatment. In this study, pristine (CFS) and ball-milled (BCFS) crayfish shell biochar pyrolyzed at 400, 600, 800 °C were fabricated for TC removal. Results indicated that the ball milling enhanced the adsorption capacity (39.1 mg/g for CFS800 versus 60.7 mg/g for BCFS800) mainly by improving the structure properties of the obtained biochar (SBET=127.9 m2/g, Vmic=0.028 cm3/g, D50=50.56 μm for CFS800 versus SBET=289.7 m2/g, Vmic=0.061 cm3/g, D50=0.623 μm for BCFS800). The main adsorption mechanism of TC on biochar was physisorption via pore filling, followed by chemisorption including hydroxyl complexation, H-bonding and electrostatic interaction. Furthermore, the studied biochar had excellent reusability and environmental adaptability and thus proved its promising application potential in the treatment of TC laden wastewater.

Cadmium removal by MgCl2 modified biochar derived from crayfish shell waste: Batch adsorption, response surface analysis and fixed bed filtration

Cadmium (Cd) pollution is regarded as a disturbing environmental problem due to its serious risks to the water body and human health. The removal of cadmium from wastewater is thus crucial to avoid its harmful effects on the ecosystem. This study comprehensively investigated Cd(II) adsorption onto MgCl2 modified biochar (MgC600) and results showed that the adsorption capacity of MgC600 was more than twice of that of pristine biochar due to its enhanced ion exchange ability. Response surface analysis revealed that reaction time played a crucial role in the Cd(II) adsorption, followed by initial concentration and solution pH. Moreover, the optimal adsorption conditions and capacity were precisely given by the quadratic regression model and thus proved that the model can be applied to predict the operation conditions of Cd(II) adsorption. Finally, a new model defined as BJP model (CtC0=11+(KJ⋅t)P) was proposed and proved to be more suitable for the fixed bed filtration process. Overall, our findings provide a promising material in treatment of Cd(II)-rich wastewater and give a clear picture of its application. More importantly, the newly developed BJP model can accurately describe the fixed bed filtration process and further promote its application in wastewater treatment.

Crayfish shell biochar for the mitigation of Pb contaminated water and soil: Characteristics, mechanisms, and applications

Biochar has been widely used in the mitigation of soil potentially toxic metals due to its high efficiency and low cost. Crayfish shell biochar (CSBC) was prepared at 300, 500, and 700 °C (referred to as CS300, CS500, and CS700, respectively) and the performance and mechanism of CSBC for mitigating Pb polluted water and soil was investigated. The results indicated that CSBC prepared at higher temperatures possessed higher pH value and ash content, more abundant pore structure, and higher stability. Pb 2+ adsorption onto CSBC fitted well with the pseudo second order and intraparticle diffusion models. The maximum adsorption capacity of Pb 2+ increased with the pyrolysis temperature, being 599.70, 1114.53, and 1166.44 mg·g −1 for CS300, CS500 and CS700, respectively. Compared with the control soil samples, the content of available Pb after applying 0.05%–5% CSBC was reduced by 1.87%–16.48% in acidic soils and 1.00%–11.09% in alkaline soils. Moreover, the fractionation of exchangeable Pb was converted to stable organic matter bound, Fe-Mn oxide bound, and residue fractions. XRD, SEM-EDS, and FTIR analysis showed that ion exchange, complexation, precipitation, and C−π interaction are the dominant interaction mechanisms. Therefore, CSBC can employ as an effective immobilizing agent for the mitigation of Pb contaminated water and soil. • Pyrolysis temperature affected the characteristics of crayfish shell biochar. • Crayfish shell biochar showed high Pb 2+ sorption capacity (599.70–1166.44 mg·g −1 ). • Main interaction mechanisms: precipitation, ion exchange, complexation, C–π interaction. • Crayfish shell biochar could decrease Pb availability in acid and alkaline soil.

Synthesis of 3D-interconnected hierarchical porous carbon from heavy fraction of bio-oil using crayfish shell as the biological template for high-performance supercapacitors

The practical application of raw biomass in high-performance supercapacitors is mainly hindered by virtue of their relatively rare efficient storage sites and low diffusion kinetics. Herein, hierarchical porous carbons (HPCs) are synthesized from heavy fraction of bio-oil (HB) based on a hard-template method accompanied by different NaOH activation temperatures. Thanks to the favorable 3D-interconnected hierarchical porous structure, ultrahigh specific surface area (3095 m2 g−1), large total pore volume (1.66 cm3 g−1), as well as reasonable content of oxygen atoms (7.83 at. %), CSB-800 delivers a prominent gravimetric specific capacitance of 351 F g−1 (0.5 A g−1), which is considerably superior or at least comparable than previously reported for other biomass-based materials. In addition, the assembled CSB-800//CSB-800 symmetric supercapacitors can reach a superior energy density of 20 W h kg−1 at a power density of 350 W kg−1 (0.5 A g−1). The route proposed for preparing HB-based HPCs broadens a new horizon in exploring large-scale synthesis of electrode materials from industrial by-product and kitchen waste.

Improvements on high-temperature stability, rheology, and stiffness of asphalt binder modified with waste crayfish shell powder

The quickly accumulated crayfish shell waste in China has led to severe environmental issues and recycling pressure. This study aims to build an efficient protocol by utilizing waste crayfish shell powder in the production of high-performance and sustainable asphalt binder. The asphalt binder modified with different contents of crayfish shell powder (5%, 10% and 20% mass ratio to control asphalt, respectively) were first prepared at the temperature of 140oC–150 °C. Then the softening point and the penetration of the prepared samples were implemented to compare the stiffness difference between the modified and original asphalt binder. The results indicated that the added shell powder increased the softening point and decreased the penetration of the control asphalt. Furthermore, the high-temperature stability of the asphalt binder was examined by the dynamic shear rheometer (DSR) tests. The DSR results revealed that adding shell powder could enhance the rutting resistance of the asphalt binder by decreasing the phase angle δ, increasing the dynamic shear modulus |G∗| and finally enhancing the rutting factor |G∗|/sinδ. After that, to compare the creep performance between the control and modified asphalt binder, the multiple stress creep recovery (MSCR) tests were employed. The results of the MSCR test showed that at the same temperature, the percent recovery was higher while the non-recoverable creep compliance Jnr of modified asphalt was lower than those of the control binder. These results indicated that the added crayfish shell powder could increase the stiffness, improve the high-temperature stability and creep resistance of the asphalt binder. Finally, fourier transform infrared spectroscopy (FT-IR) test results implied that the added CS would not affect the chemical structure of the asphalt binder, and the modification was mainly a physical process. The novelty and limitation of this study have also been detailedly explained in the discussion part. The test results could provide a reference for the engineering application of the crayfish shell powder modified asphalt material and lead to both a cleaner and greener product.

Crayfish shell biochar modified with magnesium chloride and its effect on lead removal in aqueous solution.

In this study, crayfish shell was pyrolyzed at 600°C to obtain an unmodified biochar (CS600). MgCl2 was used as a modifier to pretreat crayfish shell to produce a modified biochar (CS600-MgCl2) under the same pyrolysis conditions. The two biochars were characterized for physicochemical properties and evaluated for lead (Pb2+) sorption ability to determine the modification mechanism. Mono-element batch adsorption experiments were conducted to compare the sorption performances of CS600 and CS600-MgCl2 to Pb2+ in aqueous solutions. All the experiments were carried out at pH of 7. According to the Freundlich-Langmuir model, CS600-MgCl2 had a higher adsorption capacity (152.3mg/g) than CS600 (134.3mg/g). FTIR, SEM, XRD, BET, and ICP analyses were applied to inform the interpretation of the mechanism. CS600 was calcium-rich and mainly removed Pb2+ through the ion exchange mechanism by replacing Ca2+ in the biochar. The increased Pb2+ adsorption capacity of CS600-MgCl2 was mainly due to the enlarged specific surface area and the formation of Mg3(OH)5Cl·4H2O on the modified biochar. Findings of this study suggest that both CS600 and CS600-MgCl2 can be used to remove heavy metal ions from wastewater and MgCl2 can improve the sorption performance of biochar.

Desorption of calcium-rich crayfish shell biochar for the removal of lead from aqueous solutions

In this study, crayfish shell was pyrolyzed at 600 °C to obtain a calcium-rich biochar (CS600). The biochar was saturated with Pb2+ in batch adsorption experiment. Six desorption reagents including HCl, HNO3, H2SO4, NaOH, EDTA and EDTA-2NaCa were then used to desorb Pb2+ from the post-adsorption CS600 to determine the desorption mechanism. Lead adsorption experiments were performed to determine the adsorption capacity of the regenerated CS600. HCl, HNO3, EDTA and EDTA-2NaCa presented good desorption effect with desorption rates all over 80%. Most of the regenerated biochars lost their lead adsorption ability due to the destruction of CaCO3 mineral on their surface. Only the one desorbed by EDTA-2NaCa retained a preferable lead adsorption capacity. EDTA-2NaCa thus is a promising desorption reagent of CS600 for the removal of lead from aqueous solutions.

Novel Crayfish Shell Biochar Nanocomposites Loaded with Ag-TiO2 Nanoparticles Exhibit Robust Antibacterial Activity

A fast sol-dipping-gel method was applied to load Ag and TiO2 nanoparticles on the surface of crayfish shell biochar to make an inexpensive and novel nanocomposite. Tetra-n-butyl titanate (Ti(OC4H9)4) and silver nitrate (AgNO3) were used as the nanoparticle precursors. Crayfish shell was pyrolyzed to produce the biochar host. Paper-disk diffusion method was applied to measure antibacterial activities of the nanocomposites to E. coli. The maximum loading rate of TiO2 and Ag nanoparticles on the biochar reached 7.54% and 3.20%, respectively. Results of long-term antibacterial effect experiment showed that the Ag-TiO2-biochar had robust antibacterial activity and could be reused for multiple times. The inactivation of E. coli of initial concentration of 105 CFU/mL by Ag-TiO2-biochar under solar light reached around 99% of sterilization ratio in 5 min. In addition, the antibacterial ability of the nanocomposite was better in light than that in dark due to the presence of TiO2. Findings of this study suggest that the novel nanocomposite is a promising material for water treatment units and household water purifiers.

Simultaneous fermentation and hydrolysis to extract chitin from crayfish shell waste

Chitin is the second-most abundant bioresource and widely used in the food, agricultural, textile, biomedical, and pharmaceutical industries. However, an efficient, environmentally friendly, and economically feasible process for chitin extraction from shellfish waste remains to be explored. This study aimed to extract chitin from crayfish shell waste powder (CSP) by removing Ca2+ and protein, using Bacillus coagulans LA204 and proteinase K. A simultaneous enzymatic hydrolysis and fermentation process was conducted at 50 °C with 5% (w/v) CSP, 5% (w/v) glucose, 1000 U proteinase k g−1 CSP, and 10% inoculation of B. coagulans LA204 in a 5-L bioreactor under non-sterile conditions. After 48 h of fermentation, the deproteinization efficiency, demineralization efficiency, and chitin recovery reached 93%, 91%, and 94%, respectively. 1 mol additional glucose efficiently removed 0.91 mol calcium carbonate and 93% of the removed protein was hydrolyzed to acid-soluble protein. Simultaneous enzymatic hydrolysis and fermentation was a new strategy and a competitive biological method for chitin extraction.