Shrimp Exoskeleton Research Articles

Pelagic shrimp play dead in deep oxygen minima.

Pelagic crustaceans are arguably the most abundant group of metazoans on Earth, yet little is known about their natural behavior. The deep pelagic shrimp Hymenopenaeus doris is a common decapod that thrives in low oxygen layers of the eastern Pacific Ocean. When first observed in situ using a remotely operated vehicle, most specimens of H. doris appeared dead due to inactivity and inverted orientation. Closer inspection revealed that these animals were utilizing small, subtle shifts in appendage position to control their orientation and sink rate. In this mode, they resembled molted shrimp exoskeletons. We hypothesize that these shrimp may avoid capture by visually-cued predators with this characteristic behavior. The low metabolic rates of H. doris (0.55–0.81 mg O2 kg-1 min-1) are similar to other deep-living shrimp, and also align with their high hypoxia tolerance and reduced activity. We observed similar behavior in another deep pelagic decapod, Petalidium suspiriosum, which transiently inhabited Monterey Canyon, California, during a period of anomalously warm ocean conditions.

Organic and mineral acid demineralizations: effects on crangon and Liocarcinus vernalis – sourced biopolymer yield and properties

ABSTRACTChitin is chemically extracted from crustacean shells whose composition and structure differ from one another. It is reported that mineral acids distort chitin's physiochemical properties compared to organic acids. Investigations on the effectiveness of these acids on chitin isolation from crab and shrimp exoskeleton are carried out. Shell particles were demineralized using acetic acid (CH3COOH) and HCl while NaOH was used for deproteinization. Acetic acid possesses low potency for complete CaCO3 removal from crab shell while it fully demineralizes shrimp shell. With the use of CH3COOH, the biopolymer extracted shows characteristics of chitin but with lower content and physicochemical properties compared to chitin isolated from the shells using HCl. Mineral acid (HCl) will thus isolate chitin from exoskeletons of marine invertebrates irrespective of their shell nature while organic acid (CH3COOH) will be effective for soft shells whose embedded chitin content is more than the mineral content such as shrimp shells.

Biological Compatibility of a Polylactic Acid Composite Reinforced with Natural Chitosan Obtained from Shrimp Waste.

The aim of this work is to evaluate the effect of chitosan content (1, 3 and 5 wt %) dispersed in polylactic acid (PLA) on the structure and properties of composites. Also, the hydrolytic degradation, and the cell viability and adhesion of human MG-63 osteoblasts are analyzed to determine the composites’ suitability for use in tissue engineering. For the manufacture of the materials, natural chitosan was extracted chemically from shrimp exoskeleton. The composites were fabricated by extrusion, because it is a low-cost process, it is reproducible, and it does not compromise the biocompatibility of the materials. FT-IR and XRD show that the chitosan does not change the polymer structure, and interactions between the composite components are discarded. In vitro degradation tests show that the composites do not induce significant pH changes in phosphate buffer solution due to their low susceptibility to hydrolytic degradation. The adhesion and morphological characteristics of the osteoblasts are evaluated using confocal microscopy and scanning electron microscopy. The cell viability is determined by the MTT assay. Osteoblasts adhesion is observed on the surface of PLA and composites. A higher amount of chitosan, higher number of cells with osteoblastic morphology, and mineralized nodules are observed on the composite surface. The highest metabolic activity is evidenced at 21 days. The results suggest that the Polylactic acid/chitosan composites are potentially suitable for use as a biomaterial.

Taphonomy of ghost shrimps (Decapoda: Axiidea: Callianassidae) associated with their burrows within a middle Miocene mud volcano complex of Persian (Arabian) Gulf, Kuwait

Shallow-marine strata of the Ghar Formation exposed along the Kuwait arch in the north of Kuwait contains fields of mud volcanoes associated with an assemblage dominated by pectinid bivalves and callianassid ghost shrimps. The depositional palaeoenvironment is interpreted to be intertidal to subtidal with the water depth not exceeding 50 m and with normal to hypersaline conditions. Based on the microfossil assemblage a middle Miocene age (early Langhian) is inferred, suggesting a longer stratigraphic span of the formation despite the previous studies treating the Ghar Formation as strictly early Miocene. Callianassid body fossils and numerous trace fossils assignable to Ophiomorpha have been identified. Ghost shrimp remains consisting of isolated cheliped elements are assigned to Neocallichirus (s.l.), which is the likely producer of Ophiomorpha burrows as documented by cheliped elements present within burrows and in the substrate around them. Stable isotopes discrimination modelling confirmed that fluids in the substrate were derived from at least two sources implying the presence of active mud volcanoes in the environment inhabited by ghost shrimps. Effusive activity of mud volcanoes further enhanced disarticulation and fragmentation of callianassid remains. The micritic matrix of ghost shrimp exoskeletons is indicated to have resulted from a mixture of local seawater with fluid of continental origin. This ghost shrimp occurrence is the first formal report of fossil decapod crustaceans from Kuwait.

Evaluation of Five Chitosan Production Routes with Astaxanthin Recovery from Shrimp Exoskeletons

Shrimp waste can be potentially used as source of high value products, from biopolymers to bioactive compounds. In this work, was defined a methodology for chitosan production via of depigmentation, demineralization, deproteinization and deacetylation of chitin. Five chitosan production processes were performed from the chitin present in shrimp exoskeletons using chemical agents such as hydrochloric acid (HCl) and sodium hydroxide (NaOH). Concentrations used were 1.5 M for acid, 1.0 M and 50 % w/v for base, 85 % for ethanol and 10 % v/v for acetone, and chitosan samples obtained were compared with commercial chitosan. Results shows that percentages of deacetylation obtained varied between (80 and 81.8 %) near the degree of deacetylation of the commercial chitosan (82.1 %). The extraction process with prior depigmentation using ethanol before demineralization registered the highest value of deacetylation, and the lowest value obtained was from the product obtained via ethanol followed by a second depigmentation with acetone after deproteinization of chitin. The characteristic bands of chitosan and similarity in each sample were confirmed by FTIR are NH bonds (between 3,350 – 3,500 cm-1), NH bonds of the secondary amide (between 1,420 – 1,590 cm-1), the tertiary amide band (between 1,360 – 1,380 cm-1) and C = O bonds of the primary amide (between 1,618 – 1,630 cm-1).

Efficiency of Chitosan as a Coagulant for Wastewater from Slaughterhouses

Objective:The purpose of this work was to obtain chitosan from shrimpexoskeletons, characterize it and evaluate its coagulant activity in the turbidity removal of wastewater from slaughtering Units. Methods/Analysis: Wastewater samples had three different turbidity measures(250, 560 and 863 NTU) and with three different doses of coagulant each (50, 100 and 150 mgL-1), according to a 32experimental design. Control and ANOVA tables were used to verify if there were statistically significant differences among data with a 95% confidence level. Findings: Chitosan with a molecular weight of 3.2x106 g mol-1 and a degree of deacetylation of 74% was obtained. When used as a coagulant it is possible to obtain turbidity removals greater than 90% when initial turbidity of wastewater was equal to or greater than 560 NTU. However, and due to acid nature of coagulant extracts, pH and alkalinity of samples were influenced. Effectiveness of chitosan in wastewater treatment with high organic load and difficult treatment was verified. Application: In conclusion, it is possible to obtain excellent quality chitosan from shrimp exoskeletons and its use is convenientin alkaline wastewater. Keywords: Alkalinity, Chitosan, Coagulant Activity, pH, Wastewater from Slaughterhouses

Bacterial biofilm development during experimental degradation of Melicertus kerathurus exoskeleton in seawater.

Chitinolytic bacteria are widespread in marine and terrestrial environment, and this is rather a reflection of their principle growth substrate's ubiquity, chitin, in our planet. In this paper, we investigated the development of naturally occurring bacterial biofilms on the exoskeleton of the shrimp Melicertus kerathurus during its degradation in sea water. During a 12-day experiment with exoskeleton fragments in batch cultures containing only sea water as the growth medium at 18 °C in darkness, we analysed the formation and succession of biofilms by scanning electron microscopy and 16S rRNA gene diversity by next generation sequencing. Bacteria belonging to the γ- and α-Proteobacteria and Bacteroidetes showed marked (less or more than 10%) changes in their relative abundance from the beginning of the experiment. These bacterial taxa related to known chitinolytic bacteria were the Pseudolateromonas porphyrae, Halomonas aquamarina, Reinekea aestuarii, Colwellia asteriadis and Vibrio crassostreae. These bacteria could be considered as appropriate candidates for the degradation of chitinous crustacean waste from the seafood industry as they dominated in the biofilms developed on the shrimp's exoskeleton in natural sea water with no added substrates and the degradation of the shrimp exoskeleton was also evidenced.

Acetylation, crystalline and morphological properties of structural polysaccharide from shrimp exoskeleton

The extraction of a structural polysaccharide, α-chitin, from shrimp exoskeleton via chemical means using hydrochloric acid (HCl) and sodium hydroxide (NaOH) has been done. Concentrations of 0.4, 0.8 and 1.2M for both HCl and NaOH were chosen to evaluate the acetylation degree (DA), crystalline structure and morphology of the chitin. The N-acetyl groups’ content in the structural polysaccharide ranged between 65.6 and 99.4% in decreasing order of both acid and alkali concentrations combination used. The magnitude of chitin average hydrogen bond energy EH was majorly influenced by OH(6)…OC intra and CO…HN intermolecular hydrogen bonds as they showed more predominance than OH(3)…O(5) and OH…OC intra and intermolecular hydrogen bonds. Chitin diffraction planes, crystalline index (Crl) and crystallite size (Dhkl) were investigated by X-ray diffraction (XRD) with reflections observed on (021), (110), (130) and (013) planes. The Crl occurred between 79.4 and 87.4%, while crystallite sizes were between 0.544 and 3.64Å for the samples. Morphological study using scanning electron microscopy with energy dispersive spectroscopy SEM/EDS showed strong calcium and oxygen peaks. This established the shrimp shell surface to be composed of calcite and trace elements such as nitrogen and silicon. The observed α-chitin rough surfaces were attributed to the low degree deacetylation recorded during alkali treatment.

Removing Reactive Red 120 and 196 using chitosan/zeolite composite from aqueous solutions: Kinetics, isotherms, and process optimization

Abstract A low-cost adsorptive composite was prepared using natural zeolite, clinoptilolite, and shrimp shell wastes as raw materials. The shrimp waste was used to synthesize chitosan by the deacetylation of chitin which was extracted from the exoskeleton of crustacean shrimps. Response surface methodology (RSM) was employed to model and optimize the effect of process variables including initial dye concentration (25–100 mg/L), solution pH (3–11), adsorbent dose (1–3 g/L), and contact time (15–180 min) on the percentage of dye removal as the response. The optimum levels of independent variables for the removal of Reactive Red 120 (RR120) were time of 138.75 min, initial concentration of 43.79 mg/L, adsorbent dose of 2 g/L, and pH of 5. The optimum values for the removal of Reactive Red 196 (RR196) were time of 125.77 min, initial concentration of 44.72 mg/L, adsorbent dose of 2.5 g/L, and pH of 5. Under optimal conditions, the predicted removal percent of the model was 91.2 and 100% for RR120 and RR196, respectively. The results showed that the experimental data of RR120 were better described by Hill and Sips isotherms, and experimental data of RR196 followed Jovanovic isotherm model. The pseudo-first-order and pseudo-second-order models were employed to analyze the kinetic data. The kinetic data were well described by pseudo-second-order model with R Adj 2 values of higher than 0.98 and 0.99 for RR120 and RR196, respectively. The results showed that all of the independent variables exhibited a significant effect on dye removal.

New source of chitosan from Black Sea marine organisms identification

ABSTRACTThe Romanian Black Sea environment, due to its biodiversity, contains a lot of organism, which represents a rich natural resource of many biologically active compounds, such as: sterols, proteins, polyunsaturated fatty acid, polysaccharides, pigments and antioxidants.In their evolution, marine organisms in the Black Sea adapted excellently to the marine environment such as: low temperature, absence of light, extreme pH and pressure, low salinity, low oxygen, the presence of one toxic abiotic chemical (H2S). Moreover, they produce a wide variety of secondary metabolites (biologically active), which cannot be found in other terrestrial organisms.Chitosan is a copolymer of β-(1→4)-linked 2-acetamido-2-deoxy-D-glucopyranose and 2-amino-2-deoxy-D-glucopyranose. Usually, it is obtained by deacethylation of the natural chitin, which is extracted from the exoskeleton of marine organisms, mainly crabs and shrimps. Chitosan could have a lot of applications in biomaterials, pharmaceuticals, cosmetics, metal ion sequestration, agriculture and foodstuff treatment (flocculation, clarification) because of its efficient interaction with other polyelectrolytes.In this paper, we propose new possible source of chitosan, the spawning of Rapana venosa, a predatory gastropod, which invaded the Black Sea in earlier 1940s. Preliminary spectral studies on this biopolymer extracted from this biomaterial and another marine source (Eriphia verucosa) will be discussed and compared with that of chitosan standard in order to put in evidence the presence of chitosan in the obtained extracts.

The Use of Chitosan For Removing Selected Pollutants From Water And Wastewater – Short Review

Abstract Chitosan is a natural product derived from chitin, which is mostly found in exo-skeletons of shrimp, crab and lobster shells. This paper presents a short review of the literature regarding the use of chitosan and its modifications for removing selected pollutants from water and wastewater. In particular, the examples of removal of metal ions, dyes, anions and phenols were described. Furthermore, the possibility of the use of chitosan as a coagulant and flocculant in water and wastewater technologies are also shown. Based on the literature review described in this article it can be concluded that chitosan and especially its modifications is a very promising sorbent for removing a broad spectrum of pollutants from aqueous solutions. It also presents directions for further research in order to obtain a better knowledge of the practical applications of chitosan.

Does Chitosan Extend the Shelf Life of Fruits?

The use of hazardous formalin in increasing shelf life of fruits and protecting them from microbial decay by unscrupulous traders is a big health concern for the consumers in Bangladesh. Chitosan is a natural biopolymer produced from the exoskeletons of shrimp and crab, which slows antimicrobial activities and induces immunity of plants against microbial pests. This study aimed to evaluate the efficacy of chitosan on the shelf life extension of some local ripened fruits compared to untreated control. Three doses of chitosan solution viz. 0, 500 and 1000 ppm were sprayed in alternate day on banana (cvs. Shabri and Champa), strawberry, tomato, and oranges. It revealed that chitosan extended shelf life of all fruits by delaying the decay; however, level of protection varied in different kinds of fruits as well as in doses of the chitosan used. Among the tested fruits, decay of tomatoes was most delayed by chitosan. Spraying of both 500 and 1000 ppm of chitosan equally protected 100% decay in tomatoes until 8 days of treatments at room temperature. More than 80% protection of other fruits viz. banana, orange and strawberries by chitosan were recorded at 8, 8 and 4 day after treatment, respectively, which were remarkably higher than the untreated control. Interestingly, 500 ppm of chitosan spray gave better protection than 1000 ppm in all the tested fruits. These results suggest that lower doses of chitosan can be utilized as a natural preservative of fruits alternative to hazardous formalin. A further study with higher number of fruits, and at varying temperature and chitosan doses are needed for recommending it for practical application as a fruit preservative.

Removal of Congo Red from the aqueous phase by chitin and chitosan from waste shrimp

This work describes the adsorption process at laboratory level of Congo Red on two biopolymers from shrimp exoskeletons. Chitin obtained by demineralization and deproteinization and chitosan by additional deacetylation process of shrimp exoskeletons. Box–Behnken experimental design with three variables at three levels each one was used to evaluate the optimum conditions of the process. The analysis of the results showed that optimal parameters of adsorption process were at pH 7.0, at temperature of 50°C, and 3 h of contact time. Also, isotherms models were evaluated, showing that adsorption equilibrium for chitin was best described by the Langmuir adsorption model; in contrast the chitosan was better described by the Freundlich adsorption isotherm. The corresponding thermodynamic parameters (ΔG°, ΔH°, and ΔS°) were calculated to evaluate the nature of the adsorption process. The results showed the feasibility of the process and the spontaneous nature of adsorption with both biopolymers. The maximum adsorption capacities of chitin and chitosan obtained from the Langmuir and Freundlich isotherm model were 139 and 320 mg g−1, respectively, indicating that chitosan was the best adsorbent for Congo Red. Finally, the analysis by FT-IR confirmed the adsorption of Congo Red onto chitin and chitosan, since a peak detected at 1,153 cm−1 which may attributed to the groups SO3 of Congo Red.

A comparison of nanoindentation creep deformation characteristics of hydrothermal vent shrimp (Rimicaris exoculata) and shallow water shrimp (Pandalus platyceros) exoskeletons

Abstract

Comparación de tres metodologías para la captación de sulfitos en camarones tratados con metabisulfito de sodio

La industria acuícola en la zona sur pretende incrementar la comercialización de camarón entero en los mercados norteamericano y europeo, castigando fuertemente los camarones con melanosis o con residuos de sulfitos superiores a 100 ppm, respectivamente. La melanosis consiste en el desarrollo de una coloración negruzca en el exoesqueleto del camarón. El metabisulfito de sodio (MBS) inhibe la formación de melanosis. Para detectar residuos de sulfitos en camarones tratados con MBS se emplean los métodos de cintas colorimétricas, titulación con iodometría y titulación con Monier-Williams (M-W). Los objetivos del estudio fueron evaluar los métodos para detectar sulfitos en camarones tratados con MBS y determinar la cantidad de sulfitos detectados con el procedimiento M-W a diferentes tiempos de destilación. Se seleccionaron camarones de un estanque de producción, según las características de textura del exoesqueleto, que fueron sometidos a baños de 0.5 % y 1.0 % de MBS. También se determinaron las concentraciones de sulfitos y el desarrollo de melanosis durante ocho semanas de almacenamiento a -18°. El método de cintas colorimétricas no tiene precisión para detectar sulfitos en los camarones, el método M-W detectó más sulfitos que la iodometría (P<0.004). Se encontraron correlaciones altamente significativas con el método M-W entre los sulfitos detectados después de cada tiempo de destilación (P<0.001). Los camarones tratados con MBS mostraron una reducción de sulfitos a lo largo de ocho semanas de almacenamiento (P<0.04). El método M-W mostró ser el más preciso en la detección de sulfitos. Según los resultados del ensayo, se puede acortar el tiempo de destilado en el método M-W para detectar adecuadamente los residuos de sulfitos en el camarón. Los camarones tratados con MBS presentaron menos melanosis (P<0.02) que los no tratados durante ocho semanas de congelamiento. DOI: http://dx.doi.org/10.5377/rct.v0i14.1796 Revista Ciencia y Tecnología No. 14, junio 2014: 62-76

An investigation into mechanical strength of exoskeleton of hydrothermal vent shrimp (Rimicaris exoculata) and shallow water shrimp (Pandalus platyceros) at elevated temperatures.

This investigation reports a comparison of the exoskeleton mechanical strength of deep sea shrimp species Rimicaris exoculata and shallow water shrimp species Pandalus platyceros at temperatures ranging from 25°C to 80°C using nanoindentation experiments. Scanning Electron Microscopy (SEM) observations suggest that both shrimp exoskeletons have the Bouligand structure. Differences in the structural arrangement and chemical composition of both shrimps are highlighted by SEM and EDX (Energy Dispersive X-ray) analyses. The variation in the elastic moduli with temperature is found to be correlated with the measured compositional differences. The reduced modulus of R. exoculata is 8.26±0.89GPa at 25°C that reduces to 7.61±0.65GPa at 80°C. The corresponding decrease in the reduced modulus of P. platyceros is from 27.38±2.3GPa at 25°C to 24.58±1.71GPa at 80°C. The decrease in reduced moduli as a function of temperature is found to be dependent on the extent of calcium based minerals in exoskeleton of both types of shrimp exoskeletons.

Recovery of Astaxanthin from Shrimp Cooking Wastewater: Optimization of Astaxanthin Extraction by Response Surface Methodology and Kinetic Studies

A protein and astaxanthin-concentrated fraction (R f) can be recovered from shrimp cooking wastewater by ultrafiltration at 300 kDa, indicating that astaxanthin is somehow associated to membrane-retained proteins. Response surface analysis showed that astaxanthin can be extracted from R f using sunflower oil (3:1 v/v) under milder conditions (T < 40 °C) than directly from shrimp exoskeleton. Modeling astaxanthin extraction kinetics at 30 °C revealed that the process is a consequence of both mass transfer and hydrogen bonding between astaxanthin and oil. The freeze-dried concentrate (FR f ) showed two-phase extraction profiles with a much faster pigment recovery observed at 30 °C compared to the liquid form (R f). The best yields of astaxanthin extraction were not further improved after hydrolysis with alcalase at 45 °C for 30 min (HR f ), although higher yields were obtained when both R f and LR f were extracted in the presence of 200 mg/L butylated hydroxyanisole or ethoxyquin. Astaxanthin from this shrimp by-product has low thermal stability in oil at high temperatures (60 and 70 °C), suggesting the carotenoid is mainly free as a result of the cooking process and not bounded to proteins or lipids as it occurs in its natural form.

An investigation into environment dependent nanomechanical properties of shallow water shrimp (Pandalus platyceros) exoskeleton

The present investigation focuses on understanding the influence of change from wet to dry environment on nanomechanical properties of shallow water shrimp exoskeleton. Scanning Electron Microscopy (SEM) based measurements suggest that the shrimp exoskeleton has Bouligand structure, a key characteristic of the crustaceans. As expected, wet samples are found to be softer than dry samples. Reduced modulus values of dry samples are found to be 24.90±1.14GPa as compared to the corresponding values of 3.79±0.69GPa in the case of wet samples. Hardness values are found to be 0.86±0.06GPa in the case of dry samples as compared to the corresponding values of 0.17±0.02GPa in the case of wet samples. In order to simulate the influence of underwater pressure on the exoskeleton strength, constant load creep experiments as a function of wet and dry environments are performed. The switch in deformation mechanism as a function of environment is explained based on the role played by water molecules in assisting interface slip and increased ductility of matrix material in wet environment in comparison to the dry environment.

Structural-Nanomechanical Property Correlation of Shallow Water Shrimp (Pandalus platyceros) Exoskeleton at Elevated Temperature

This investigation reports the nanomechanical properties of shallow water shrimp exoskeleton at temperatures ranging from 30 °C to 80 °C measured using nanoindentation experiments. Scanning Electron Microscopy (SEM) measurements suggest that the shrimp exoskeleton has the Bouligand structure in its layers, a key characteristic of the crustaceans. The thickness of the layers and packing density are found to be different from that of lobsters and crabs reported earlier in the literature. Mechanical properties at high temperatures are determined using micro materials nanoindentation test set up combined with the hot stage. The properties measured during nanoindentation test are corrected for the creep and thermal drift during the experiments. The reduced modulus values are found to be around 28 GPa at 30 °C that reduces to approximately 24 GPa at 80 °C. The hardness values also decrease from 1.6 GPa at 30 °C to around 1.2 GPa at 80 °C. The indentation size effect is found to be absent at all temperatures. Creep mechanisms of polymers like materials and its temperature dependence are discussed to give more insight into the deformation mechanism.

Chitosan and its oligosaccharide derivatives (chito-oligosaccharides) as feed supplements in poultry and swine nutrition.

Chitosan is a non-toxic polyglucosamine, widespread in nature, which is deacetylated to varying degrees form of chitin, a component of exoskeleton of shrimps, crabs and insects. Because chitosan contains reactive functional groups, that is, amino acids and hydroxyl groups, it is characterised by antimicrobial, anti-inflammatory, anti-oxidative, antitumor, immunostimulatory and hypocholesterolemic properties when fed as dietary additive for farm animals. This article reviews and discusses the results of studies on the effects of dietary chitosan and its oligosaccharide derivatives on performance and metabolic response in poultry and pigs, that is, haematological, biochemical and immunological blood characteristics, microbiological profile of intestines, intestinal morphology and digestibility of nutrients, as well as on the quality of meat and eggs. The results of most of the experiments presented in this review indicate that chitosan used as a feed additive for poultry and pigs has some beneficial, biological effects, including immunomodulatory, anti-oxidative, antimicrobial and hypocholesterolemic properties. These properties of chitosan, unlike many other kinds of feed additives, were often reflected in improved growth performance (body weight gain and/or feed conversion ratio) of young animals, that is, broiler chickens and weaned pigs.