Comparative Proteomics Reveals the Spoilage-Related Factors of Shewanella putrefaciens Under Refrigerated Condition

Shewanella putrefaciens is a microorganism with strong spoilage potential for aquatic products. This study aimed to investigate the potential spoilage factors of S. putrefaciens by comparative proteomic analysis. The spoilage potential of two strains of S. putrefaciens (00A and 00B) isolated from chilled spoiled bigeye tuna was investigated. The results of total volatile basic nitrogen (TVB-N), trimethylamine (TMA) in fish inoculated with S. putrefaciens, extracellular protease activity of S. putrefaciens, and degradation of fish proteins indicated that the spoilage potential of S. putrefaciens 00A was much higher than that of 00B. Fish proteins are usually degraded by spoilage microorganism proteases into small molecular peptides and amino acids, which are subsequently degraded into spoilage metabolites in bacterial cells, leading to deterioration of fish quality. Thus, proteomic analysis of the extracellular and intracellular proteins of 00A vs. 00B was performed. The results indicated that the intracellular differentially expressed protein (IDEP) contained 243 upregulated proteins and 308 downregulated proteins, while 78 upregulated proteins and 4 downregulated proteins were found in the extracellular differentially expressed protein (EDEP). GO annotation revealed that IDEP and EDEP were mainly involved in cellular and metabolic processes. KEGG annotation results showed that the upregulated proteins in IDEP were mainly involved in sulfur metabolism, amino acid metabolism, and aminoacyl-tRNA biosynthesis, while downregulated proteins were related to propanoate metabolism. In contrast, EDEP of KEGG annotation was mainly involved in ribosomes, quorum sensing, and carbohydrate metabolism. Proteins associated with spoilage containing sulfur metabolism (sulfite reductase, sulfate adenylyltransferase, adenylyl-sulfate kinase), amino acid metabolism (biosynthetic arginine decarboxylase, histidine ammonia-lyase), trimethylamine metabolism (trimethylamine-N-oxide reductase), and extracellular proteins (ATP-dependent Clp protease proteolytic subunit) were identified as upregulated. These proteins may play a key role in the spoilage potential of S. putrefaciens. These findings would contribute to the identification of key spoilage factors and understanding of the spoilage mechanism of microorganisms.

Myofibrillars and Sarcoplasmic Proteins Separated The Effect of Different Preservation and Cooking Methods on Functional Characteristics of From Common Carp and Silver Carp Prof.

The current study dealt with the use of methods of preserving (freezing and salting with drying), cooking methods (grilling and cooking in broth and frying) and studying their effect on functional characteristics (solubility, amount of water and oil absorbed, viscosity, emulsification, foaming, gel formation) of myofibrillars and sarcoplasmic proteins separated from carp meat, common and silver carp diagnosed with electrophoresis technique, the study was conducted during the period (10/2018-1/2020). The results were as follows: 1. Dried fibrous proteins and dried sarcoplasm proteins separated from fish meat have given a good functional properties compared to commercial cow's albumin. 2. It was found that the percentage of solubility and gelatinization of commercial cow's albumin protein was higher than in the myofibrillars and sarcoplasmic proteins separated from the two types of fish, whereas the amount of water absorbed by the commercial cow's albumin protein was less than of myofibrillars and sarcoplasmic proteins, while the amount of absorbed oil, viscosity, and emulsion composition. The commercial cow's albumin was comparable to the myofibrillars and sarcoplasmic proteins, and when comparing the foam properties of the myofibrillars and sarcoplasmic proteins of common carp and silver carp with the commercial cow's albumin at a concentration of 1% and at the normal pH=7, it was found that the foam size and persistence of sarcooplasmic proteins were close to the size and persistence of the foam for the commercial protein at the normal pH, while the volume and stability of the foam for myofibrillars proteins were slightly lower than in cow's albumin. 3. It was observed that the solubility values in the myofibrillars proteins and the sarcoplasmic proteins of the samples were close to each other when using preservation methods while the solubility of the myofibrillars proteins was lower than the solubility of the sarcoplasm proteins of the cooked samples. It was found that the amount of oil absorbed by the myofibrillars proteins was higher than the sarcoplasmic proteins, but that its viscosity and its ability to bind water and its ability to form gel were lower than it, and the capacity of emulsifiers of protein myofibrillars and their stability was higher than the capacity and the stability of emulsions of sarcoplasm proteins, as for the type of fish and the type of protein stability of emulsions, it was noted that there was a slight difference in the capacity of emulsions and the stability of emulsions for myofibrillars proteins as well as for sarcoplasm proteins. The emulsification values did not seem different between the two types of fish. 4. It was found that freezing contributed to reducing solubility and the amount of water absorbed while it had a role in increasing the amount of oil absorbed to fish proteins more than salting and drying. The freezing, as well as salting and drying were reduced the viscosity of proteins a little bit, also freezing reduced stability of emulsionsfor two type of fish proteins,but salting and drying was rised it, and the degree of influence of the measured foam property in myofibrillars and sarcoplasmic proteins of the fish species by means of preservation and cooking different methods was very small because the values were closely related, and we did not find a specific pattern that we could apply in terms of challenging degree of difference, freezing and salting with drying, grilling and frying and cooking in the broth sometimes susceptibility raises values formation of foam and other reduce it. 5. The solubility of proteins that measured on fish which cooked in broth was more than the solubility of grilled and fried samples. It was observed that the solubility values in myofibrillars proteins and sarcoplasm proteins for the cooked samples were close to each other, and the amount of water and absorbed oil, foam properties and viscosity of the measured proteins in cooked fish were not affected by the cooked methods whose used because the closely related of values. 6. Generally the results showed that the solubility and viscosity values in the samples of common carp were lower than in the silver carp which preserved and cooked by different ways, but the ability of common carp to bind the oil was higher than that of silver carp when using conservation methods while the values were close at the use of cooking methods, and we noted that there were no noticeable differences between myofibrillars proteins and sarcoplasmic proteins for the two fish species in their ability to bind water and their ability to form gel. It was also noted that there was a slight difference in the capacity of emulsions and their stability to myofibrillars proteins as well as to proteins sarcoplasm between the two types of fish. 7. The fish type, preservation methods, cooking methods, and di-interference had a significant effect at the probability level (P ≤ 0.05) on the percentage of solubility and the amount of water and oil absorbed by the myofibrillars and sarcoplasmic proteins separated from the meat of these fish, but did not significantly impact the viscosity of the protein.

Agricultural Bio-Stimulant Activity of Fish Protein Hydrolysate from Common Silver Belly (Gerres subfasciatus)

Taking into account of using the fish industry wastes and for expanding the incentive to a few under used fish species, protein hydrolysates from fish proteins are being set up by a few specialists everywhere throughout the world. Fish Protein Hydrolysates (FPH) are breakdown results of enzymatic transformation of fish proteins into smaller units like peptides, which typically contain 2-20 amino acids. Their worth has been expanded by utilizing them as fluid bio compost, feed supplement and bioorganic fertilizer. From the research carried out at our laboratory, Dry fish silver belly with both microbe and enzyme acquired from cultural broth of lactobacillus species, catalyst papain demonstrated positive upgrade of development and advancement of plants tested. In view of the yield of FPH concentrates from both microbial and enzymatic hydrolysis, the pace of seedling life list in Urad dhal, green gram and okra got higher in 0.1-0.5% convergence of dry fish hydrolysate from lactobacillus treated than in the control variation. With respect to the seeds of urad dhal, green gram and okra, the germination rate and seedling energy list from treated seeds surpassed control by 19.11-128.71%. The positive effect of dry fish protein hydrolysate by microbial procedure on germination rate, seedling life record rate in 3 kinds of seeds is the reason for the improvement of protein hydrolysate item for application in crop creation utilizing dry fish squanders. The Seedling grown in 0.5% concentration of fish hydrolysates showed significant increase in seedling vigour index of Urad dhal (13.29 ± 0.12 %), Green gram (14.1 ± 0.17%) and Okra (5.39 ± 0.43 %) was recorded through one way Analysis of Variance (ANOVA). By HPLC determination amino acid results determined that protein hydrolysates process can be stopped on 7th day (643.56ppm) whereas @ 10th day amino acid decreased (326.24ppm). Results suggest that probiotic assumes a superior job in dry fish protein hydrolysates than compounds when contrasted and yield and prudent astute.

Fish Protein and Its Derivatives: Functionality, Biotechnology and Health Effects

Animal derived proteins provide the essential amino acid requirements of a healthy diet. Among animal proteins, fish proteins have a well-balanced amino acid composition that are imperative for beneficial synthesizing and utilizing proteins in the body. Lack or low levels of any amino acid reduce the other amino acid utilization proportionately. This is why plant-derived proteins are potentially at a disadvantage for use in the body since they have relatively low levels of the essential amino acids methionine and lysine. Health studies have revealed that fish protein is suggested as a weight-loss diet to obese patients.

Fish Protein and Its Derivatives: Functionality, Biotechnology and Health Effects

Animal derived proteins provide the essential amino acid requirements of a healthy diet. Among animal proteins, fish proteins have a well-balanced amino acid composition that are imperative for beneficial synthesizing and utilizing proteins in the body. Lack or low levels of any amino acid reduce the other amino acid utilization proportionately. This is why plant-derived proteins are potentially at a disadvantage for use in the body since they have relatively low levels of the essential amino acids methionine and lysine. Health studies have revealed that fish protein is suggested as a weight-loss diet to obese patients.

Interactions of Fish Proteins and Volatile Flavor Compounds: Mechanisms, Affecting Factors and Analytical Methods

: The removal of volatile compounds with unfavorable fishy odor from fish has attracted considerable research attention especially in surimi production industry. The binding of these volatile compounds by fish proteins are reported to affect the deodorization of fishy odor. To remove the protein-bound fishy substances effectively, the mechanisms underlying the interaction between proteins and flavor substances and methods that can extract and analyze the aromatic substances have been extensively studied. This paper briefly reviews the typical fishy compounds and the combination modes and mechanisms of fish proteins with these compounds. Moreover, factors affecting the interactions including protein conformation and solution conditions are discussed in detail.

Influence of high hydrostatic pressure on the optical properties of minced fish proteins

In the functioning of various biological systems, an extremely important role is played by the dynamic properties of optically anisotropic protein macromolecules, such as translational movements, temporal correlations, and transfer processes, which are determined by the surface charge, molecular weight, molecular shape, and the nature of intermolecular interactions. An experimental study of the influence of high hydrostatic pressure on the optical properties of pike perch minced fish proteins at room temperature was carried out in this work. The intensities of the radiation transmitted through a thin plane-parallel layer of minced fish were measured, which was subjected to hydrostatic compression at a rate of ≈3 MPa/s and ≈17 MPa/s. It was found that with increasing pressure, the intensity of the transmitted light decreases nonmonotonically; in this case, the experimental plots of the I(P) dependence show the presence of broad attenuation bands of the intensity of the radiation transmitted through the sample, located at pressures of about 150, 300, and 700 MPa. The observed attenuation bands are associated with the appearance of scattering centers formed as a result of denaturation of macromolecules of proteins of various types with different functional purposes contained in the muscle tissue of pike perch.

In silico evaluation of marine fish proteins as nutritional supplements for COVID-19 patients

To date, no specific drug has been discovered for the treatment of COVID-19 and hence, patients are in a state of anxiety.