Chitin Waste Research Articles

Highly efficient shrimp shell recovery by solid-state fermentation with Streptomyces sp. SCUT-3

Owing to the rising global production of crustaceans, chitinous waste is being increasingly produced but poorly recycled. The development of new sustainable biorefinery methods is of urgent necessity for replacing traditional chemical recycling methods. A newly isolated Streptomyces sp. SCUT-3 strain, with robust protease secretion and chitin utilization abilities, was used for recycling shrimp shell waste (SSW) in this study. Under optimized conditions, 92.6 % of SSW protein was recovered by 5 d of solid-state fermentation (SSF), of which two-thirds was harvested as free amino acids (FAAs), and one-third as oligopeptides. The deproteinized SSW residue from SSF was easily subjected to calcium extraction, and 92.0 % of calcium was recovered in 30 min using lactic acid. The remaining residue was recovered as chitin products with high purity, a high acetylation rate of 90.5 %, and a low degree of crystallization. Altogether, the Streptomyces SSF-plus-lactic-acid method developed in this study can convert 100 g SSW into 33.6 g FAAs, 16.7 g oligopeptides, 7.4 g calcium (in the form of calcium lactate), and 19.5 g chitin. Analyses of the economic benefits and environmental impact revealed that this method has a low cost (20 %), high profit (10-fold), and a low environmental footprint (1.08 %) compared to traditional-chemical methods, and is superior to other newly developed physicochemical, enzymatic, and biofermentation methods. Higher protease production and constitutive chitinase expression SCUT-3 strains are under-constructed. The possibility of the enhanced super shell degradation strains to realize higher protein yields, synchronous protein, and chitin degradation, or sequential protein and chitin degradation for chitinous waste recycling is discussed. This green sustainable method developed in the study will light the way for the future shell waste recycling industry.

Chitinase-Assisted Bioconversion of Chitinous Waste for Development of Value-Added Chito-Oligosaccharides Products.

Chito-oligosaccharides (COSs) are the partially hydrolyzed products of chitin, which is abundant in the shells of crustaceans, the cuticles of insects, and the cell walls of fungi. These oligosaccharides have received immense interest in the last few decades due to their highly promising bioactivities, such as their anti-microbial, anti-tumor, and anti-inflammatory properties. Regarding environmental concerns, COSs are obtained by enzymatic hydrolysis by chitinase under milder conditions compared to the typical chemical degradation. This review provides updated information about research on new chitinase derived from various sources, including bacteria, fungi, plants, and animals, employed for the efficient production of COSs. The route to industrialization of these chitinases and COS products is also described.

Extraction of chitin from edible crab shells of Callinectes sapidus and comparison with market purchased chitin.

Chitin and its derived products have immense economic value due to their vital role in various biological activities as well as biomedical and industrial application. Insects, microorganism and crustaceans are the main supply of chitin but the crustaceans shell like shrimp, krill, lobsters and crabs are the main commercial sources. Chitin content of an individual varies depending on the structures possessing the polymer and the species. In this study edible crabs' shells (Callinectes sapidus) were demineralized and deproteinized resulting in 13.8% (dry weight) chitin recovery from chitin wastes. FTIR and XRD analyses of the experimental crude as well as purified chitins revealed that both were much comparable to the commercially purchased controls. The acid pretreatment ceded 54g of colloidal chitin that resulted in 1080% of the crude chitin. The colloidal chitin was exploited for isolation of eighty five chitinolytic bacterial isolates from different sources. Zone of clearance was displayed by the thirty five isolates (41.17%) succeeding their growth at pH 7 on colloidal chitin agar medium. Maximum chitinolytic activity i.e. 301.55 U/ml was exhibited by isolate JF70 when cultivated in extracted chitin containing both carbon and nitrogen. The study showed wastes of blue crabs can be utilized for extraction of chitin and isolation of chitinolytic bacteria that can be used to degrade chitin waste, resolve environmental pollution as well as industrial purpose.

OPTIMIZATION OF PROCESS PARAMETERS FOR DYE REMOVAL THROUGH CHITINOUS WASTE BY RESPONSE SURFACE METHODOLOGY

Color present in water itself first contaminant and dyes which are harmful for human is a vast problem. Chitinous waste a problem for environment can be an alternative approach for removal of dyes from water. Nanoparticles made up of chitinous waste are used in this study. Chitosantripolyphosphate (CS-TPP) nanoparticles showed prominent result in removal of reactive blue 19 and reactive blue 198 dyes. Both the dyes were totally (100%) removed by the use of CS-TPP. Statistical analysis though Response Surface Methodology (RSM) and Box Behnken Design (BBD) to optimize pH and concentration were also carried out. After optimization it was evaluated that pH 6.5 and higher Chitosan-TPP concentration showed the highest removal of dyes.

The potential of degrading natural chitinous wastes to oligosaccharides by chitinolytic enzymes from two Talaromyces sp. isolated from rotten insects (Hermetia illucens) under solid state fermentation.

It is difficult to produce chitin oligosaccharides by hydrolyzing untreated natural chitinous waste directly. In this study, two fungi Talaromyces allahabadensis Hi-4 and Talaromyces funiculosus Hi-5 from rotten black soldier fly were isolated and identified through multigene phylogenetic and morphological analyses. The chitinolytic enzymes were produced by solid state fermentation, and the growth conditions were optimized by combining single-factor and central composite design. The best carbon sources were powder of molting of mealworms (MMP) and there was no need for additional nitrogen sources in two fungi, then the maximum chitinolytic enzyme production of 46.80 ± 3.30 (Hi-4) and 55.07 ± 2.48 (Hi-5) U/gds were achieved after analyzing the 3D response surface plots. Pure chitin (colloidal chitin) and natural chitinous substrates (represented by MMP) were used to optimize degradation abilities by crude enzymes obtained from the two fungi. The optimum temperature for hydrolyzing MMP (40°C both in two fungi) were lower and closer to room temperature than colloidal chitin (55°C for Hi-4 and 45°C for Hi-5). Then colloidal chitin, MMP and the powder of shrimp shells (SSP) were used for analyzing the products after 5-day degradation. The amounts of chitin oligosaccharides from SSP and MMP were about 1/6 (Hi-4), 1/17 (Hi-5) and 1/8 (Hi-4), 1/10 (Hi-5), respectively, in comparison to colloidal chitin. The main components of the products were GlcNAc for colloidal chitin, (GlcNAc)2 for MMP, and oligosaccharides with higher degree of polymerization (4-6) were obtained when hydrolyzing SSP, which is significant for applications in medicine and health products.

Synergic chitin degradation by Streptomyces sp. SCUT-3 chitinases and their applications in chitinous waste recycling and pathogenic fungi biocontrol

The genus Streptomyces comprises the most important chitin decomposers in soil and revealing their chitinolytic machinery is beneficial for the conversion of chitinous wastes. Streptomyces sp. SCUT-3, a chitin-hydrolyzing and a robust feather-degrading bacterium, was isolated previously. The potential chitin-degrading enzymes produced by SCUT-3 were analyzed in the present study. Among these enzymes, three chitinases were successfully expressed in Pichia pastoris at comparatively high yields of 4.8 U/mL (SsExoChi18A), 11.2 U/mL (SsExoChi18B), and 17.8 U/mL (SsEndoChi19). Conserved motifs and constructive 3D structures of these three exo- and endochitinases were also analyzed. These chitinases hydrolyzed colloidal chitin to chitin oligomers. SsExoChi18A showed apparent synergic effects with SsEndoChi19 in colloidal chitin and shrimp shell hydrolysis, with an improvement of 29.3 % and 124.9 %, respectively. Compared with SsExoChi18B and SsEndoChi19, SsExoChi18A exhibited the strongest antifungal effects against four plant pathogens by inhibiting mycelial growth and spore germination. This study provided good candidates for chitinous waste-processing enzymes and antifungal biocontrol agents. These synergic chitin-degrading enzymes of SCUT-3 are good targets for its further genetical modification to construct super chitinous waste-degrading bacteria with strong abilities to hydrolyze both protein and chitin, thereby providing a direction for the future path of the chitinous waste recycling industry.

Screening of chitin degrading bacteria from the gut of Asian common toad Duttaphrynus melanostictus: Implication for valorization of chitin rich seafood waste

Chitin is a structural component of many invertebrates and the second most abundant biopolymer after cellulose. Owing to its high insolubility, waste management of chitin rich seafood has severe environmental consequences. Despite the value added bioconversion of waste chitin into commodity products like reducing sugars, its biodegradation by bacteria is still lacking. To this end, we have isolated and characterized chitin degrading bacteria from the gut of common Asian toad, Duttaphrynus melanostictus . The isolates, FG4 and ND3 demonstrated highest chitin degradation activities of 1.44 ± 0.129 U/mL and 1.269 ± 0.138 U/mL respectively. Molecular phylogeny using 16S rRNA gene sequence affiliated FG4 to Stenotrophomonas maltophila and ND3 to Bacillus paramycoides , respectively. Among the tested substrates, highest chitinase activities of 4.210 ± 0.070 U/mL and 1.724 ± 0.494 U/mL were exhibited by S. maltophila FG4 on prawn shells (PS) and chitin flakes (CF), respectively. Similarly, the highest substrate degradation ratio of prawn shells and chitin flakes were 49.52% and 38.15% by S. maltophila FG4. Furthermore, scanning electron microscopy revealed adhesion of bacteria and creation of pores on the substrates. The Fourier transform infrared spectroscopy (FTIR) and X - ray diffraction analysis revealed hydrolysis of prawn shells and chitin flakes by bacteria. Further, the high-resolution mass spectrometric (HRMS) analysis confirmed production of N-acetyl D glucosamine by S. maltophila FG4 on prawn shells. Thus, the present study identifies D. melanostictus gut as a unique reservoir to isolate chitinolytic bacteria that may have potential industrial and therapeutic applications. • First report of bioprospection of amphibian guts for bacteria capable of chitin hydrolysis. • Gut chitinolytic isolates could utilize sea food wastes as sole carbon source. • Applications in production of valuable byproducts such as N-acetyl-D-glucosamine.

Isolation, characterization, and genome sequencing of a novel chitin deacetylase producing Bacillus aryabhattai TCI-16.

Chitin deacetylase (CDA) is a chitin degradation enzyme that catalyzes the conversion of chitin to chitosan by the deacetylation of N-acetyl-D-glucosamine residues, playing an important role in the high-value utilization of waste chitin. The shells of shrimp and crab are rich in chitin, and mangroves are usually recognized as an active habitat to shrimp and crab. In the present study, a CDA-producing bacterium, strain TCI-16, was isolated and screened from the mangrove soil. Strain TCI-16 was identified and named as Bacillus aryabhattai TCI-16, and the maximum CDA activity in fermentation broth reached 120.35 ± 2.40 U/mL at 36 h of cultivation. Furthermore, the complete genome analysis of B. aryabhattai TCI-16 revealed the chitin-degrading enzyme system at genetic level, in which a total of 13 putative genes were associated with carbohydrate esterase 4 (CE4) family enzymes, including one gene coding CDA, seven genes encoding polysaccharide deacetylases, and five genes encoding peptidoglycan-N-acetyl glucosamine deacetylases. Amino acid sequence analysis showed that the predicted CDA of B. aryabhattai TCI-16 was composed of 236 amino acid residues with a molecular weight of 27.3 kDa, which possessed a conserved CDA active like the known CDAs. However, the CDA of B. aryabhattai TCI-16 showed low homology (approximately 30%) with other microbial CDAs, and its phylogenetic tree belonged to a separate clade in bacteria, suggesting a high probability in structural novelty. In conclusion, the present study indicated that the novel CDA produced by B. aryabhattai TCI-16 might be a promising option for bioconversion of chitin to the value-added chitosan.

Increased production of chitinase by a Paenibacillus illinoisensis isolated from Brazilian coastal soil when immobilized in alginate beads.

The accumulation of chitin waste from the seafood industry is a serious environmental problem. However, this residue can be degraded by chitinases and its subproducts, such as chitosan, economically exploited. In this study, a chitinase producer bacteria, identified as Paenibacillus illinoisensis, was isolated from the Brazilian coastal city of Terra de Areia - Rio Grande Do Sul (RS) and was immobilized within alginate beads to evaluate its chitinase production. The alginate beads containing cells presented an average size of 4mm, 99% of immobilization efficiency and increased the enzymatic activity in 40.71% compared to the free cells. The biomass during enzymatic production increased 62.01% and the total cells leaked from the alginate beads corresponded to 6.46% after 96h. Immobilized cells were reused in a sequential batch system and remained stable for production for up to four 96-h cycles, decreasing only 21.04% of the initial activity at the end of the fourth cycle. Therefore, the methodology used for cell immobilization resulted in adequate beads to maintain cell viability during the enzymatic production, increasing enzymatic activity, showing low cell leakage from the support and appropriate recyclable capacity.

Chitinase enzyme in bacterial species and fungal growth inhibition against A. niger and Penicillium

Chitin is the most abundant polysaccharide in nature, second after cellulose as it found in the structure of crustaceans, insects and fungi being a significant component. Sea food waste disposal pose a great problem as chitin in nature degrade at a very gradual rate. Efforts are being made to use chitinase enzyme from different organisms to increase the rate and efficiency of chitin waste disposal. Moreover, chitinase and chitinase producing bacteria are widely being exploited to be used as bio-control agents to inhibit crop pathogens. On the basis of its mechanism of action, chitinase can either be endochitnase or exochitinase. Endo chitinases randomly hydrolyses internal glycosidic bonds in chitin. Exochitinase is exoglycosidase that can be divided into two subtypes based on the specificity of their action Chitinase is synthesized by a number of different microbes including bacteria, fungi and other organisms like mammals, insects etc. This paper gives information about the production of different chitinase enzymes from different bacterial gram-positive species. Antifungal activity for different isolates were tested against A. niger and Penicillium. The isolates showed varying degree of fungal growth inhibition against different fungi.

Upcycling from chitin-waste biomass into bioethanol and mushroom via solid-state fermentation with Pleurotus ostreatus

This study aimed to bioconvert of chitin waste biomass into oyster mushroom food and bioethanol through solid-state fermentation with Pleurotus ostreatus. The biological efficiency of the different recipes ranged from 75.66% to 130.61%. Three kinds of greenhouse gases (CO2, CH4, and N2O) were detected during oyster mushroom cultivation, whereas control group had 17.9% higher CO2 emissions than the shell waste-based formulas. The nutrient enrichment capability of fruiting bodies was demonstrated as follows: N (0.33)＞P (0.24)＞C (0.1). Among the four shell waste recipes, 50% crayfish shell and 50% chestnut hull were demonstrated to be optimal for the production of P. ostreatus mushrooms and bioethanol fuel. After solid state fermentation, the chitin-protein structure and calcium carbonate in shell waste were depolymerized and degraded and resulting in 24.53% higher than the initial substrate in enzymatic digestibility with chitinase. The highest total theoretical yield of ethanol was 7.72 ml/100 g and N-acetylglucosamine contributes 66.63%. This strategy could help divert excess nutrients in chitin waste biomass away from the environment into protein-rich oyster mushroom food and green biofuels production.

Estudio Fisicoquímico de Quitina y Quitosana obtenidas a partir del exoesqueleto de camarón café (Farfantepenaeus californiensis)

This work describes the obtention of chitin and chitosan from the brown shrimp exoskeleton (Farfentepenaeus californiensis), which is collected from the Gulf of California. The chitin isolation process was carried out by a consecutive treatment that includes demineralization and deproteinization. On the other hand, the preparation of chitosan was conducted through alkaline hydrolysis, and the product was purified by using a membrane filters series to homogenize the size of the macromolecular chains. According to the methodology, the yield of chitin and chitosan was around 34 % and 20 % (dry weight), respectively. The materials were characterized by FTIR spectroscopy and thermogravimetric analysis. Also, the chitosan sample was analyzed by proximal test, viscometric-average molecular weight, and deacetylation degree. The products exhibited chemical structure and physicochemical properties comparable to biopolymers isolated from similar sources reported in the literature. Chitosan was found to have a degree of acetylation of 15.87 % (by 1H-NMR analysis) and Mv=170 kDa. The results suggest that the chitinous waste from the Sea of Cortes coast can be considered a promising source for the preparation of chitosan and used for several applications in the region.

A Contemporary Appraisalon Impending Industrial and Agricultural Applications of Thermophilic-Recombinant Chitinolytic Enzymes from Microbial Sources.

The ability of chitinases to degrade the second most abundant polymer, chitin, into potentially useful chitooligomers and chitin derivatives has not only rendered them fit for chitinous waste management but has also made them important from industrial point of view. At the same time, they have also been recognized to have an imperative role as promising biocontrol agents for controlling plant diseases. As thermostability is an important property for an industrially important enzyme, various bacterial and fungal sources are being exploited to obtain such stable enzymes. These stable enzymes can also play a role in agriculture by maintaining their stability under adverse environmental conditions for longer time duration when used as biocontrol agent. Biotechnology has also played its role in the development of recombinant chitinases with enhanced activity, thermostability, fungicidal and insecticidal activity via recombinant DNA techniques. Furthermore, a relatively new approach of generating pathogen-resistant transgenic plants has opened new ways for sustainable agriculture by minimizing the yield loss of valuable crops and plants. This review focuses on the potential applications of thermostable and recombinant microbial chitinases in industry and agriculture.

Bioconversion of chitin waste through Stenotrophomonas maltophilia for production of chitin derivatives as a Seabass enrichment diet

Marine wastes pose a great threat to the ecosystem leading to severe environmental hazards and health issues particularly the shellfish wastes. The shellfish waste which contains half of the amount of chitin can be efficiently transformed into useful products. Various approaches for the hydrolysis of chitin like physical, chemical, and enzymatic processes are there. Still, the use of enzyme chitinase is well documented as an effective and eco-friendly method. The present study summarizes the isolation of chitinase enzyme producing bacteria from different shrimp waste disposal sites in Parangipettai (India), and the possible use of an enzyme hydrolyzate as an immunostimulant to Asian Seabass (Lates calcarifer). The potential chitinase-producing bacteria were identified by 16S rRNA gene sequencing as Stenotrophomonas maltophilia. After purification, the chitinase specific activity was 5.01 (U/ml) and the protein content was 72 mg and the recovery rate was 48.06%. The optimum pH and temperature for the chitinolytic activity were 6.5 and at 35–50 °C, respectively. The animal experiment trial was done with our feed supplements which included 0.0 (control), 0.5%, 1% and 2% of chitin degraded product. All the supplementary feed had an optimal 42% (w/w) of crude protein. The feed protein level was 41–43% on average and gross energy was 13–17 kcal/g and the feed was observed to exhibit a significantly higher (p < 0.05) survival rate, condition factor, specific growth rates, and body weight gain was also found to be promising compared to other fishes fed with control diet only. The red blood cells (RBC) and white blood cell (WBC) counts were found to increase significantly after being challenged with infection in animals fed with chitin derivatives from 1st week to 3rd week when compared to the control. The hematocrit (Hct) values were low on the 2nd and 3rd week in infected fish fed with chitin derivatives. This low level was due to infection lyses of the red blood cells and increased nitro blue tetrazolium reduction. The control diet-fed fish showed 70% mortality but the chitin derivative supplemented fishes showed only 20% mortality post-infection. The results of the study encompass that the use of chitin-derivate enriched feed further is taken into large-scale approaches thereby benefitting the aquaculture sector.

Lipogenesis in Sentul chickens of starter phase inhibited by irradiated chitosan

This experiment explores the effect and optimal levels of irradiated Chitosan (IrC) in the diet on lipogenesis and its effect on the blood lipid profile of the Sentul Chickens starter phase. The IrC was generated from shrimp waste chitin, and in addition to being a feed supplement, it has the potential to reduce environmental pollution. Furthermore, Sentul chickens were 100 samples, reared from 0-8 weeks, and the observed variables included triglyceride, cholesterol, and blood Non-Esterified Fatty Acid (NEFA). A completely randomized design (CRD) experimental method was used with four treatments and five replications. The treatments were K0 = basal diet without IrC, K1 = 300 ppm IrC in basal diet, K2 = 350 ppm IrC in basal diet, K3 = 400 ppm IrC in the basal diet. Meanwhile, the samples used for analysis were 40 individuals from the research object based on the average body weight of the population. The results showed that the provision of rations containing IrC (K1) 300 ppm, (K2) 350 ppm, and (K3) 400 ppm had a significant effect (P<0.05) on triglyceride, cholesterol, and NEFA profile in Sentul Chickens blood of the starter phase.

Amino-functionalized polysaccharide derivatives: Synthesis, properties and application

Polysaccharides, cellulose and chitin are fundamental structural biopolymers of our biome, they therefore demonstrate relatively high tensile strength compared to other biopolymers and great diversity. Aqueous insolubility is a natural requirement for these polymers to be fit for purpose. However, non-natural aminated polysaccharides, such as 6-deoxy-6-amino derivatives, display improved solubility profiles, thus allowing further modification in a wider range of protic and aprotic polar solvents. Improved aqueous solubility and additional charge density aids, among others, modest antimicrobial, antioxidant, anticancer and gene transfection properties. Cellulosic and chitinous feedstock is naturally abundant and ideal for further valorisation. However, limitations in environmentally desirable solvents and inconsistency in chemical processing are a key hurdle in the path to commercial exploitation of 6-deoxy-6-aminocellulose and 6-deoxy-6-aminochitosan. This review intents to highlight the successes and challenges in the chemical process methodology that influence optimal valorisation of cellulosic and chitinous waste in the context of exploiting waste derived biopolymers. Note that this review is focused on the synthesis of 6-deoxy-6-amino derivatives and not 6-O-linked aminated derivatives.

A review on valorization of chitinous waste

A review on valorization of chitinous waste

Enhancement of microalgal biomass, lipid production and biodiesel characteristics by mixotrophic cultivation using enzymatically hydrolyzed chitin waste

There is a growing interest for the mixotrophic cultivation of microalgae using sustainable natural carbon sources. Chitin from shrimp waste was hydrolyzed using chitinase from Trichoderma asperellum and was exploited for the mixotrophic cultivation of microalgae. Chitin saccharification was optimized using Box-Behnken design to produce 50.41% (w/w) of reducing sugars using chitin, 0.83% (w/v), chitinase, 2.92 (v/v), temperature, 40 °C and time, 4.48 h. The biomass productivity of Tetradesmus obliquus and Aphanocapsa sp. was promoted to 39.1 and 40.57 mg L−1 day−1 in the presence of 0.5 g L−1 of N-acetylglucosamine oligomers (GlcNAc), which was estimated to be ∼1.9 and ∼2-folds higher than the autotrophic conditions, respectively. Modified Logistic kinetic model confirmed higher growth rates and shortened lag-time of the mixotrophic cultures. The lipid productivity of both microalgae species was >1.5-times higher than the autotrophic conditions. Nitrate removal from the culture medium was found to be an effective strategy to increase both lipid content and lipid productivity for T. obliquus, but this strategy was not effective for Aphanocapsa sp. Fatty acid analysis revealed an increase of saturated fatty acids under mixotrophic cultivation for both microalgae species. Additionally, several biodiesel evaluation parameters indicated superior characteristics for the mixotrophic culture compared to the autotrophic conditions. Accordingly, mixotrophic growth of microalgae using GlcNAc as a new, sustainable carbon and nitrogen source opens a new avenue for biofuel production with an effective waste conversion into valuable commodities.

Production of Thermophilic Chitinase by Paenibacillus sp. TKU052 by Bioprocessing of Chitinous Fishery Wastes and Its Application in N-acetyl-D-glucosamine Production.

The bioprocessing of chitinous fishery wastes (CFWs) to chitinases through fermentation approaches has gained importance owing to its great benefits in reducing the enzyme production cost, and utilizing chitin waste. In this work, our study of the chitinase production of Paenibacillus sp. TKU052 in the presence of different kinds of CFWs revealed a preference for demineralized crab shells powder (deCSP); furthermore, a 72 kDa chitinase was isolated from the 0.5% deCSP-containing medium. The Paenibacillus sp. TKU052 chitinase displayed maximum activity at 70 °C and pH 4–5, while Zn2+, Fe3+, Triton X-100, Tween 40, and SDS exerted a negative effect on its activity, whereas Mn2+ and 2-mercaptoethanol were found to potentially enhance the activity. Among various kinds of polysaccharide, Paenibacillus sp. TKU052 chitinase exhibited the best catalytic activity on colloidal chitin (CC) with Km = 9.75 mg/mL and Vmax = 2.43 μmol/min. The assessment of the hydrolysis of CC and N-acetyl chitooligosaccharides revealed that Paenibacillus sp. TKU052 chitinase possesses multiple catalytic functions, including exochitinase, endochitinase, and N-acetyl-β-D-glucosaminidase activities. Finally, the combination of Paenibacillus sp. TKU052 chitinase and Streptomyces speibonae TKU048 N-acetyl-β-D-glucosaminidase could efficiently convert CC to N-acetyl-D-glucosamine (GlcNAc) with a production yield of 94.35–98.60% in 12–24 h.

Seafood Processing Chitin Waste for Electricity Generation in a Microbial Fuel Cell Using Halotolerant Catalyst Oceanisphaera arctica YHY1

In this study, a newly isolated halotolerant strain Oceanisphaera arctica YHY1, capable of hydrolyzing seafood processing waste chitin biomass, is reported. Microbial fuel cells fed with 1% chitin and 40 g L−1 as the optimum salt concentration demonstrated stable electricity generation until 216 h (0.228 mA/cm2). N-acetyl-D-glucosamine (GlcNAc) was the main by-product in the chitin degradation, reaching a maximum concentration of 192.01 mg g−1 chitin at 120 h, whereas lactate, acetate, propionate, and butyrate were the major metabolites detected in the chitin degradation. O. arctica YHY1 utilized the produced GlcNAc, lactate, acetate, and propionate as the electron donors to generate the electric current. Cyclic voltammetry (CV) investigation revealed the participation of outer membrane-bound cytochromes, with extracellular redox mediators partly involved in the electron transfer mechanism. Furthermore, the changes in structural and functional groups in chitin after degradation were analyzed using FTIR and XRD. Therefore, the ability of O. arctica YHY1 to utilize waste chitin biomass under high salinities can be explored to treat seafood processing brine or high salt wastewater containing chitin with concurrent electricity generation.