Digestive proteinases from the marine fish processing wastes of the South-West Atlantic Ocean: Their partial characterization and comparison.

Fish processing generates plenty of waste that is directly discarded in open-air dumps and water sources, or treated in the same way as urban solid waste, causing serious pollution problems. The waste represents a significant source of high-value bioproducts with potential applications in different industrial processes such as the production of feed, fertilizers, biodiesel and biogas, detergent additives and cosmetics. The objective of this study was to characterize and compare specific activities under different pH values and temperature conditions of acid and alkaline proteinases and viscera yield from the following fish species: Argentine hake Merluccius hubbsi, Brazilian flathead Percophis brasiliensis, Brazilian codling Urophycis brasiliensis and Stripped weakfish Cynoscion guatucupa. Individuals were fished off the coast of Mar del Plata (Argentina) by a commercial fleet and the viscera were immediately extracted and kept on ice until use. Stomach proteinases from four species had the highest activity at pH 2, with stability in the range of pH 2-4. The optimum pH was 11.5 from intestinal enzymes of C. guatucupa, M. hubbsi and P. brasiliensis and 9.5 from intestinal enzymes of U. brasiliensis. Alkaline proteinases from all species were highly stable in the range of 7-11.5. The optimum temperature of stomach proteinases from the four species studied were 30 and 50°C, with stability at 10 and 30°C during 150 min. The optimum temperature of intestinal enzymes from the tested species were 50°C with high stability at 10 and 30°C during 150 min. Alkaline proteinase from all species and acid proteinases from C. guatucupa were inactive at 70°C after 150 min, while there was a residual activity lower than 5% at 80°C on pre-incubated stomach enzymes of M.hubbsi, P. brasiliensis and U. brasiliensis after 5, 10 and 20 min, respectively. Digestive proteinases recovered in this study could be appropriate for technological usage, reducing manufacturing costs, obtaining revenue from fishery wastes, and contributing to the reduction of environmental pollution.

Optimization, purification, and biochemical characterization of thermoalkaliphilic lipase from a novel Geobacillus stearothermophilus FMR12 for detergent formulations.

This study was aimed to produce a high compatible thermoalkaliphilic lipase (TA) with detergents from new thermophilic bacterial strains utilizing fish wastes for industrial application. Among bacterial isolates, a new Geobacillus stearothermophilus FMR12 efficiently utilized fish wastes at a concentration of 20% (w/v), exhibiting highly lipolytic activity at extreme thermal and alkaline pH conditions. Optimized fermentation parameters of TA lipase production were ascertained, promoting the productivity of the TA lipase from 424 to 1038 U/ml. Purification results of TA lipase exposed prominent specific activity of 4788 U/mg, purification fold of 12.44, and 7.8% yield. The purified TA lipase demonstrated outstanding activity and stability in a temperature range of 40-95 °C and pH (4-11), revealing optimal activity at 70 °C and pH 9. The molecular weight of the enzyme was estimated to be 63 kDa. Compared to control, the TA lipase activity was promoted in the presence of calcium chloride. Likewise, Triton X-100 enhanced the activity of the TA lipase, recording 128% of the control enzyme. Interestingly, the TA lipase conserved higher than 90% of its activity after blending with commercial detergents, emphasizing its competence for detergent formulations.

Biomateriales para Regeneración de Tejido Óseo Extraídos de Desechos de Pescado / Biomaterials for Bone Tissue Regeneration Extracted from Fish Wastes

Resumen Los biomateriales para regeneración ósea comúnmente se basan en el diseño natural del hueso, el cual mezcla la dureza de un material cerámico como la hidroxiapatita con la flexibilidad de un polímero como el colágeno. Ambos materiales pueden extraerse de los desechos del pescado consumido en la dieta humana, tales como escamas, piel e incluso huesos. Esta extracción tiene la ventaja de aportar biomateriales naturales, de baja toxicidad y como añadido, que evitan la transmisión de enfermedades que se ha reportado para colágenos provenientes de animales mamíferos. En este trabajo se hace una revisión de bibliografía referente a la extracción de colágeno tipo I, precursores de hidroxiapatita y síntesis de compósitos de ambos, para proponer la recuperación de estos biomateriales como una alternativa amigable con el ambiente y útil para usos médicos.

Abstract Biomaterials for bone tissue regeneration are commonly based in the natural design of bone where the stiffness of a ceramic material as hydroxyapatite is combined with the flexibility of a polymer such as collagen. Both materials can be extracted from human consumed fish waste, such as scales, bones and skin. The recovery of these biomaterials from fish waste has the advantage of yielding natural materials of low toxicity, avoiding the possible disease transmission found for the collagen coming from mammalians. In this article, we review several reports about collagen type I and hydroxyapatite precursors extraction, and composite synthesis, from fish waste in order to propose these methods as a green alternative for biomaterials useful for medical purposes.

Bitterness of fish protein hydrolysate and its debittering prospects.

Fish processing by-products often generated as discard can enzymatically be processed into a product known as fish protein hydrolysates (FPH). FPH is a good source of amino acid and peptides with bioactivities. FPH can be added to foods to improve nutritive values and bioactivities. However, bitterness in FPH, associated with hydrophobicity, degree of hydrolysis, molecular weight, proline residues, type of enzymes, and amino acid sequences has limited its uses in foods. Thus, FPH is used in foods at low levels. Numerous procedures such as extraction with alcohol, activated carbon treatment, Maillard reaction, cyclodextrin, chromatographic separation, and enzymatic hydrolysis with exopeptidase and plastein reaction have been explored to remove the bitterness of FPH. These methods can lower bitterness and improve its taste. However, changes in structure and loss of some peptides may occur. FPH with less or no bitterness can therefore be used at higher levels to alleviate nutrition deficiencies in foods. PRACTICAL APPLICATIONS: Fish protein hydrolysate (FPH) is a nutritive ingredient, which can be produced from fish processing by-products. However, bitterness in FPH has limited its potential use as a nutritive ingredient. As a result, it is incorporated into foods at low levels. Nevertheless, application of several reported debittering processes could assist to solve the problem of bitterness in FPH. The debittering can improve sensory property of FPH, thus widening its utilization.

Characterization of haloalkalophilic organic solvent tolerant protease for chitin extraction from shrimp shell waste.

Halophilic organic solvent tolerant protease (HOSP) producing Paracoccus saliphilus APCMST-CS5 was isolated from the marine sediment samples and identified through 16S rRNA sequence analysis. P. saliphilus APCMST-CS5 registered maximum HOSP production of 1,321.70U/ml in the medium contained the most significant parameters such as shrimp shell powder (SSP), CaCl2, NaCl, and sardinella powder (SP), obtained through Placket-Burman and Response Surface Methods. HOSP was further purified to 22.68 fold purity with 29.71 U/mg specific activity and its molecular weight was 39kDa. The HOSP was stable at 60°C, 9.0 pH, 3.0M NaCl concentration and it also showed maximum activity at other tested parameters. Interestingly the purified HOSP showed better antibiofilm ability against tested pathogens. Also, the HOSP effectively deproteinized (85.64%) shrimp shell chitin which in turn maximum and exhibited higher antioxidant activity. The commercial and experimental shrimp shell chitin showed similar peak pattern in FTIR and 13C CP/MAS NMR spectral analysis.

Preparation of biological fish silage and its effect on the performance and meat quality characteristics of quails (Coturnix coturnix japonica)

The aim of the present study was to produce fish silage by lactic acid fermentation and evaluate its use in feeding of quails (Coturnix coturnix japonica). An oven-dried mixture of fish silage and soybean meal (1:1 w/w) was used to prepare the diets with different levels of inclusion (0, 10, 20 and 30%) and evaluate its effect on the performance and meat quality of 160 quails. The inclusion level did not affect the growth and feed conversion ratio. The carcass yield (70.3%) and sensory quality of breast meat were not significantly different among the treatments (p>0.05). However, the concentration of unsaturated fatty acids such as oleic (C18:1n9C), linoleic (C18:2n6C), linolenic (C18:3n3), arachidonic (C20:4n6), cis eicosapentaenoic (C20:5n3) and cis docosahexaenoic (C22:6n3) increased in quail breast meat with the inclusion of fish silage:soybean mixture in the diet (p<0.05). Fish silage and its use in quail diets could offer a good alternative for fish waste utilization as feedstuff component for the improvement of fatty acid composition in its breast meat.