Extraction Hydrolysates from Larimichthys Polyactis Swim Bladder Using Enzymatic Hydrolysis

As a kind of biopolymer,hydrolysates of fish swim bladder,safer than those of land mammals,are widely used in food,cosmetics as well as pharmaceutical and biomedical fields for their biocompatibility,biodegradability,and weak antigenicity.To enhance hydrolysate production,in this paper,the papain and alcalase hydrolysis processes of larimichthys polyactis swim bladder were optimized with orthogonal experiments.With 89.5%hydrolysate yield,the optimal processing conditions for alcalase were solid-liquid ratio of 1:30,enzyme concentration of 0.7%,and extraction time of 6 h.As for papain,under the optimal processing conditions:solid-liquid ratio of 1:20,enzyme concentration of 0.5%,and extraction time of 8 h,the hydrolysate yield was 65.1%.To obtain higher hydrolysate yields,the ultrasonic pretreatments were implemented before the optimal enzyme hydrolysis processes.With ultrasonic waves of 100 W for 50 min,the hydrolysate yields were increased 2.1%(alcalase)and 4.5%(papain),respectively.The Fourier Transform Infrared(FTIR)spectroscopic analysis revealed that the hydrolysates extracted by papain exist in triple-helical forms.The Ultra-Violet(UV)absorption spectra indicated that the aromatic amino acids in the hydrolysates had strong absorptions in the wavelength range of 240 nm–300 nm.The results of this research demonstrate that the alcalase hydrolysates have better solubility in water and the solution is more stable under ambient temperature.However,the hydrolysates extracted by papain have a gel property and are insoluble in weak acid at room temperature,which is more suitable for applications in feedstock of biomedical.

Fish Swim Bladder-Derived Porous Carbon for Defluoridation at Potable Water pH

The levels of fluoride in various ground water sources in East Africa are above the World Health Organization upper limit of 1.5 mg/L. Research on diverse defluoridation technologies has proven that adsorption stands out as an affordable, efficient, and facile technology. Fish swim bladder-derived porous carbon (FBPC) activated by KOH and surface oxidized by nitric acid was successfully investigated as an adsorbent for defluoridation at portable water pH. The FBPC was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). Batch methods were used to study physiochemical parameters viz., initial fluoride concentration, temperature, adsorbate dosage, contact time and pH. Freundlich, Temkin, Langmuir and Dubinin-Radushkevich isotherms were plotted and analyzed to understand the adsorption process. Bangham, Weber Morris, pseudo first and second-order models were used to elucidate the kinetics of adsorption. Optimal conditions for fluoride removal were found to be: pH of 6, FBPC adsorbent dose of 5.0 g/L and contact time of 50 min. Flouride adsorption followed pseudo second-order kinetic model and Langmuir isotherm best describes the adsorption process.

Preventive effects of the polysaccharide of Larimichthys crocea swim bladder on carbon tetrachloride(CCl_4)-induced hepatic damage

The aim of the present study was to determine the preventive effects of the polysaccharide of Larimichthys crocea swim bladder(PLCSB) on CCl4-induced hepatic damage in ICR mice.The in vitro preventive effects of PLCSB on CCl4-induced liver cytotoxic effect were evaluated in BRL 3A rat liver cells using the MTT assay.The serum levels of AST,ALT,and LDH in mice were determined using commercially available kits.The levels of IL-6,IL-12,TNF-α,and IFN-γ were determined using ELISA kits.The pathological analysis of hepatic tissues was performed with H and E staining,and the gene and protein expressions were determined by RT-PCR and Western blotting,respectively.PLCSB(20 μg·m L-1) could increase the growth of BRL 3A rat liver cells treated with CCl4.The serum levels of AST,ALT,and LDH were significantly decreased when the mice were treated with two doses of PLCSB,compared with the control mice(P < 0.05).PLCSB-treated groups also showed reduced levels of the serum pro-inflammatory cytokines IL-6,IL-12,TNF-α,and IFN-γ.PLCSB could decrease the liver weight,compared to the CCl4-treated control mice.The histopathology sections of liver tissues in the 100 mg·kg-1 PLCSB group indicated that the animals were recovered well from CCl4 damage,but the 50 mg·kg-1 PLCSB group showed necrosis to a more serious extent.The 100 mg·kg-1 PLCSB group showed significantly decreased mR NA and protein expression levels of NF-κB,i NOS,and COX-2,and increased expression of IκB-α compared with the CCl4-treated control group.In conclusion,PLCSB prevented from CCl4-induced hepatic damage in vivo.

A porous hydrogel scaffold mimicking the extracellular matrix with swim bladder derived collagen for renal tissue regeneration

As a worldwide public health issue, chronic kidney disease still lacks of effective therapeutic approaches due to the challenges in conventional organ transplantation and dialysis. Renal tissue engineering offers an advantageous therapeutic or regenerative option over typical donor organ. However, despite the great progress of decellularized extracellular matrix based scaffold for the renal regeneration, several safety concerns and complex composition still remain to be addressed. Herein, the extracellular matrix-mimicking hydrogel scaffolds were developed through covalent and physical cross-linking between swim bladder-derived natural collagen(COL) and anti-fibrosis chondroitin sulfate(CS) derivatives.The biomimetic hydrogels showed proper mechanical property, excellent thermal stability and high biocompatibility both in vitro and in vivo, by altering the mass ratio of COL and CS. When implanted in partially nephrectomized rat model, the 1 COL/2CS scaffold enable it recruit more native kidney cells, reduce the tubular damage, and even induce the regeneration of renal tubular-like tissue and restore renal metabolic function more effectively comparing with the pure 2COL and 2CS scaffold. These results suggest that the biomimetic scaffold is a promising functional platform for treating renal diseases.

Differential effects of internal tagging depending on depth treatment in Atlantic salmon:a cautionary tale for aquatic animal tag use

Electronic tags are widespread tools for studying aquatic animal behavior;however,tags risk behavioral manipulation and negative welfare outcomes.During an experiment to test behavioral differences of Atlantic salmon Sal mo salar in different aquaculture cage types,including ones expected to elicit deeper swimming behavior,we found negative tagging effects depending on whether cages were depth-modified.In the experiment,data storage tags implanted in Atlantic salmon tracked their depth behavior and survival in unmodified sea-cages and depth-modified seacages that forced fish below or into a narrow seawater-or freshwater-filled snorkel tube from a 4 m net roof to the surface.All tagged individuals survived in unmodified cages;however,survival was reduced to 62%in depth-modified cages.Survivors in depth-modified cages spent considerably less time above 4 m than those in unmodified cages,and dying individuals in depth-modified cages tended to position in progressively shallower water.The maximum depth that fish in our study could attain neutral buoyancy was estimated at 22 m in seawater.We calculated that the added tag weight in water reduced this to 8 m,and subtracting the tag volume from the peritoneal cavity where the swim bladder reinflates reduced this further to 4 m.We conclude that the internal tag weight and volume affected buoyancy regulation as well as the survival and behavior of tagged fish.Future tagging studies on aquatic animals should carefully consider the buoyancy-related consequences of internal tags with excess weight in water,and the inclusion of data from dying tagged animals when estimating normal depth behaviors.