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ABSTRACT: Shellfish waste components contain significant levels of high quality protein and are therefore a potential source for biofunctional high-value peptides. The feasibility of applying a pilot scale enzymatic hydrolysis process to whole Mytilus edulis and, by fractionation, recover hydrolysates presenting a biological activity of interest, was evaluated. Fractions were tested on four immortalized cancerous cell lines: A549, BT549, HCT15 and PC3. The 50 kDa fraction, enriched in peptides, presented anti-proliferative activity with all cell lines and results suggest a bioactive molecule synergy within the fraction. At a protein concentration of 44 µg/mL, the 50 kDa fraction induced a mortality of 90% for PC3, 89% for A549, 85% for HCT15 and of 81% for BT549 cell lines. At the low protein concentration of only 11 µg/mL the 50 kDa fraction still entails a cell mortality of 76% for A549 and 87% for PC3 cell lines. The 50 kDa fraction contains 56% of proteins, 3% of lipids and 6% of minerals on a dry weight basis and the lowest levels detected of taurine and methionine and highest levels of threonine, proline and glycine amino acids. The enzymatic hydrolysis process suggests that Mytilus edulis by-products should be viewed as high-valued products with strong potential as anti-proliferative agent and promising active ingredients in functional foods.
Marine Drugs 01/2013; 11(4):975-990. · 3.85 Impact Factor
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ABSTRACT: Antibacterial peptide fractions generated via proteolytic processing of snow crab by-products exhibited activity against Gram-negative and Gram-positive bacteria. Among
the bacterial strains tested, peptide fractions demonstrated inhibitory activity against the Gram-negative bacteria such as
Aeromonas caviae, Aeromonas hydrophila, Campylobacter jejuni,
Listonella anguillarum, Morganella morganii, Shewanella putrefasciens, Vibrio
parahaemolyticus and Vibrio vulnificus and against a few Gram-positive bacteria such as Listeria monocytogenes, Staphylococcus epidermidis and Streptococcus agalactiae. The principal bioactive peptide fraction was comprised mainly of proteins and minerals (74.3 and 15.5%, respectively). Lipids
were not detected. The amino acid content revealed that arginine (4.6%), glutamic acid (5.3%) and tyrosine (4.8%) residues
were represented in the highest composition in the antibacterial peptide fraction. The optimal inhibitory activity was observed
at alkaline pH. The V. vulnificus strain, most sensitive to the peptide fraction, was used to develop purification methods. The most promising chromatography
resins selected for purification, in order to isolate peptides of interest and to carry out their detailed biochemical characterization,
were the SP-Sepharose™ Fast Flow cation exchanger and the Phenyl Sepharose™ High Performance hydrophobic interaction media.
The partially purified antibacterial peptide fraction was analyzed for minimum inhibitory concentration (MIC) determination,
and the value obtained was 25μgml−1. Following mass spectrometry analysis, the active peptide fraction seems to be a complex of molecules comprised of several
amino acids and other organic compounds. In addition, copper was the main metal found in the active peptide fraction. Results
indicate the production of antibacterial molecules from crustacean by-products that support further applications for high-value
bioproducts in several areas such as food and health.
KeywordsAntibacterial activities-Peptide fractions-Snow crab by-products
Probiotics and Antimicrobial Proteins 04/2012; 2(3):197-209.
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ABSTRACT: Mounting evidence suggests that the benefits of fish consumption are not limited to the well-appreciated effects of omega-3 fatty acids. We previously demonstrated that cod protein protects against the development of diet-induced insulin resistance. The goal of this study was to determine whether other fish protein sources present similar beneficial effects. Rats were fed a high-fat, high-sucrose diet containing protein from casein or fish proteins from bonito, herring, mackerel, or salmon. After 28 days, oral glucose tolerance tests or hyperinsulinemic-euglycemic clamps were performed; and tissues and plasma were harvested for biochemical analyses. Despite equal energy intake among all groups, the salmon-protein-fed group presented significantly lower weight gain that was associated with reduced fat accrual in epididymal white adipose tissue. Although this reduction in visceral adiposity was not associated with improved glucose tolerance, we found that whole-body insulin sensitivity for glucose metabolism was improved using the very sensitive hyperinsulinemic-euglycemic clamp technique. Importantly, expression of both tumor necrosis factor-α and interleukin-6 was reduced in visceral adipose tissue of all fish-protein-fed groups when compared with the casein-fed control group, suggesting that fish proteins carry anti-inflammatory properties that may protect against obesity-linked metabolic complications. Interestingly, consumption of the salmon protein diet was also found to raise circulating salmon calcitonin levels, which may underlie the reduction of weight gain in these rats. These data suggest that not all fish protein sources exert the same beneficial properties on the metabolic syndrome, although anti-inflammatory actions appear to be common.
Metabolism: clinical and experimental 02/2011; 60(8):1122-30. · 2.59 Impact Factor
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ABSTRACT: For several years in the Quebec fisheries' industry, landings of pelagic fish have been calculated at over 4000 tons. These under-exploited species, rich in lipids and proteins, could be used in valuable new products. In the present study, hydrolysates of mackerel and herring were produced and utilized as sources of peptones in the formulation of new bacterial culture media. The molecular weight distribution analysis showed that molecules present in the hydrolysates were lower than 1300 Da for herring, and lower than 930 Da for mackerel. The formulated media were compared with reference media using 6 bacterial strains (3 lactic acid (LAB) and 3 non-lactic). The absorbance (OD) and carbohydrate measurements revealed that the formulated media possessed similar yields in comparison with the reference media. Finally, the inhibition of Listeria innocua by LAB bacteriocins was evaluated. Results obtained for Pediococcus acidilactici demonstrated high activities for each medium studied. Thus, the medium containing herring peptones generated the highest bacteriocin titre (32768 AU/mL), followed by both the medium containing mackerel peptones and the MRS7 medium (16384 AU/mL). Each medium containing the fish hydrolysates efficiently supported the growth of the bacterial strains. Pelagic fish peptones are promising as a novel bacterial culture media.
Canadian Journal of Microbiology 11/2009; 55(11):1240-9. · 1.36 Impact Factor
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ABSTRACT: Food research on fish has demonstrated that they constitute excellent nutritional components. The aim of the present work, was to process herring (Clupea harengus) using Protamex® and evaluate the distribution of nutrients in various fractions obtained following membrane filtration. The fish starting material was composed of approximately 88% water and the dry matter contained 59% crude proteins, 33% lipids and 5% minerals. The recovery of fish dry matter in the liquid hydrolysate was 67.8%. Most protein enriched fractions demonstrate a well-balanced amino acid composition, notably the most essential amino acids. These protein fractions are characterised by biomolecules having a relatively low molecular weight (45 kDa and less) range. Even though the process could be optimised, the biochemical and nutritional analyses indicate that the herring may serve as high-value products for future applications in the health and food sectors.
International Journal of Food Science & Technology 10/2009; 44(11):2113 - 2119. · 1.26 Impact Factor
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ABSTRACT: Snow crab (Chionoecetes opilio) constitutes valuable and nutritional sources of components, such as proteins, lipids and chitin. The present investigation was undertaken to evaluate the feasibility of applying a pilot scale enzymatic hydrolysis process of snow crab by-products, followed by fractionation, in order to recover enriched high-valued compounds. The yield of snow crab by-products recovered after manual processing; on a dry weight was 87.4%. The by-products (raw materials) were mainly moist (approximately 78%), and contained 42.9% proteins, 14.8% lipids, 25.7% minerals, 16.2% chitin, all expressed on a dry weight. The fatty acid profile of snow crab by-products and all fractions obtained following processing showed a higher content in mono-unsaturated fatty acids (MUFAs; approximately 50%), followed by polyunsaturated fatty acids (PUFAs; approximately 20%) and saturated fatty acids (SFAs; approximately 15%). The n-3/n-6 ratio was approximately 10 and represents a good index of nutritional value for snow crab oil by-products. Most protein enriched fractions demonstrate a well-balanced amino acid composition, notably the most essential amino acids. These protein fractions are characterized by biomolecules having a relatively low molecular weight (35 kDa and less) range. The enzymatic hydrolysis process developed in this study shows that snow crab by-products should to be viewed as having the potential of being identified as high-valued products. Even though the process could be optimized, it is controllable, and depending on hydrolyses conditions, the products obtained are reproducible and well defined. Results presented in this study indicate that snow crab by-products may serve as excellent nutritional components for future applications in the health and food sectors.
Bioresource technology 08/2009; 100(13):3332-42. · 4.25 Impact Factor
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ABSTRACT: Research on fish composition has demonstrated that they constitute a promising source of molecules with health benefits. In the present study, Atlantic mackerel (Scomber scombrus) was processed using Protamex® and the distribution of nutrients in various fractions obtained following membrane filtration was analysed. The fish starting material was approximately 84% water and the dry matter contained 42.7% proteins, 45.2% lipids and 5.6% minerals. The recovery of fish dry matter in the liquid hydrolysate was 77.8%. Most of the fractions were protein-enriched and characterised by a well-balanced amino acid composition, notably in terms of the most essential amino acids and by molecules of relatively low molecular weight (≤42 kDa). Even before process optimising, the biochemical and nutritional analyses indicate that the Atlantic mackerel may provide high-value products for future applications in the health and food sectors.
International Journal of Food Science & Technology 07/2009; 44(8):1609 - 1618. · 1.26 Impact Factor
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ABSTRACT: Antimicrobial peptides possess cationic and amphipathic properties that allow for interactions with the membrane of living cells. Bacteriocins from lactic acid bacteria, in particular, are currently being studied for their potential use as food preservatives and for applications in health care. However, bacteriocin exploitation is often limited owing to low production yields. Gene cloning and heterologous protein or peptide production is one way to possibly achieve overexpression of bacteriocins to support biochemical studies. In this work, production of recombinant active pediocin PA-1 (PedA) was accomplished in Escherichia coli using a thioredoxin (trx) gene fusion (trx-pedA) expression approach. Trx-PedA itself did not show any biological activity, but upon cleavage by an enterokinase, biologically active pediocin PA-1 was obtained. Recombinant pediocin PA-1 characteristics (molecular mass, biological activity, physicochemical properties) were very similar to those of native pediocin PA-1. In addition, a 4- to 5-fold increase in production yield was obtained, by comparison with the PA-1 produced naturally by Pediococcus acidilactici PAC 1.0. The new production method, although not optimized, offers great potential for supporting further investigations on pediocin PA-1 and as a first-generation process for the production of pediocin PA-1 for high-value applications.
Canadian Journal of Microbiology 12/2007; 53(11):1246-58. · 1.36 Impact Factor
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ABSTRACT: The bacteriocin pediocin PA-1 produced by Pediococcus acidilactici PAC 1.0 offers significant potential as a food preservative and as an antimicrobial agent in the medical area. However, low production yields and difficulties in obtaining significant amounts of pure pediocin PA-1 have limited, in part, its biochemical and physical characterization. In the present study, we describe a simple and more efficient purification strategy for pediocin PA-1. A hydrophobic interaction chromatography step using an octyl-Sepharose column was introduced for final purification and polishing. The new method is a scalable one, uses only two steps and yields highly purified pediocin PA-1 with a recovery as high as 73%, which is at least two to three times more than that of the methods reported so far. Highly purified, biologically active pediocin PA-1 of the correct molecular mass (4624 Da, with two disulphide bridges) was obtained. Fourier-transform infrared analysis runs at p2H 6 indicated that pediocin PA-1 was more structured than similar pediocin PA-1 samples purified using the earlier purification scheme.
Biotechnology and Applied Biochemistry 03/2006; 43(Pt 2):77-84. · 1.53 Impact Factor
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ABSTRACT: Expression of the pedA gene from Pediococcus acidilactici, coding for mature bacteriocin Pediocin PA-1, was investigated using the yeast Pichia pastoris to obtain larger quantities of pediocin to support additional studies, including structure-function research. Following various cloning strategies, a KM71H (Mut(s)) strain was selected. A significant concentration (74 microg/ml) of extracellular recombinant pediocin was obtained but the pediocin showed no biological activity. Supernatant fluids from P. pastoris cultures, harboring or not pedA, inhibited the biological activity of natural pediocin PA-1. The recombinant pediocin appeared as a mixture of three main fractions (7-8, 11, 20 kDa vs. 4.6 kDa for natural pediocin PA-1). The recombinant pediocin was also less hydrophobic and behaved differently when subjected to isoelectric focusing. Strong evidence indicated that some "collagen-like" material was tightly associated, most probably via covalent binding, to the recombinant pediocin. The "collagen-like" material was most probably responsible for the lack of biological activity of the recombinant pediocin and for the differences observed regarding some of the physico-chemical properties. Both the recombinant pediocin and natural pediocin were sensitive to collagenase, suggesting that pediocin PA-1 may possess a somewhat "collagen-like" nature. Interestingly, recombinant pediocin preparations showed the ability to assemble into fibrils.
Protein Expression and Purification 11/2005; 43(2):111-25. · 1.59 Impact Factor
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ABSTRACT: The emergence of bioactive food compounds (nutraceutical compounds) with health benefits provides an excellent opportunity for improving public health. The incorporation of bioactive compounds into food systems is therefore of great interest to researchers in their efforts to develop innovative functional foods that may have physiological benefits or reduce the risk of disease beyond basic nutritional functions. However, the effectiveness of these products in preventing diseases relies on preserving the bioavailability of their active ingredients. This represents undoubtedly a great challenge since these molecules are generally sensitive to environmental conditions encountered in food processes (i.e., temperature oxygen, and light) or in the gastrointestinal tract (i.e., pH, enzymes presence of other nutrients), which limit their activity and potential health benefits. However, bio- and microencapsulation can be used to overcome these limitations. Whey proteins, also known as the serum proteins of milk, are widely used in food products, because of their high nutritional value and their ability to form gels, emulsions, or foams. The aim of this article is to provide information on the different types of materials obtained from whey proteins and to examine their use as bioencapsulation and delivery systems.
Hemijska Industrija. 01/2003;
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ABSTRACT: Whey protein beads were successfully produced using a new emulsification/cold gelation method. The principle of this method is based on an emulsifying step followed by a Ca(2+)-induced gelation of pre-denatured (80 degreesC/30 min) whey protein. Beads are formed by the dropwise addition of the suspension into a calcium chloride (CaCl(2)) solution. IR results show that bead formation has a pronounced effect on the secondary structure of whey protein, which leads to the formation of intermolecular hydrogen-bonded beta-sheet structures. Their preparation conditions (CaCl(2) concentrations of 10, 15, and 20% (w/w)) influence their sphericity and homogeneity: an increase in CaCl(2) favors regular-shaped beads. The physicochemical and mechanical characterizations of beads were also carried out. Their properties, such as swelling, elasticity, deformability, and resistance at fracture, change according to pH levels (1.9, 4.5, and 7.5) and preparation conditions. Indeed, protein chain networks exhibit different behavior patterns with respect to their charge. Finally, bead degradation by enzymatic hydrolysis reveals that beads are gastroresistant and form good matrixes to protect fat-soluble bioactive molecules such as retinol, that have in vivo intestinal absorption sites. The experiment demonstrated the potential of whey protein beads to protect molecules sensitive (i.e., vitamins) to oxidation.
Biomacromolecules 3(2):239-48. · 5.48 Impact Factor
