FEATURE LifeBioencapsulation: Customised solutions for unusual aquafeeds
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he need to supplement aquafeeds with a wide range of additives including probiotics, prebiotics and nutraceuticals is currently a major issue in aquaculture, owing to the demand for solutions aimed at overcoming the physiological and productive consequences associated with intestinal overload in farmed fish. Noticeable changes have been observed as a result of increasing amounts of vegetable protein added to commercial feeds as an alternative to fishmeal. The quest for solutions to those disorders caused by nutritional factors is nowadays a burgeoning research field, as feed industries are particularly interested in nutritional supplements that could improve the properties of aquafeeds. However, new additives frequently imply a need for new delivery strategies, since many additives of potential interest in fish nutrition cannot finally be added to feeds. Limitations related to additive deterioration during feed processing (extrusion involves high pressure and temperature) or to inactivation during digestive transit or to the impossibility of guaranteeing precise dosage restrict the efficient utilisation of many of such substances. Although oral delivery would be, when possible, the preferred route of administration in aquaculture, the constraints mentioned above are of particular interest in the case of live microorganisms used as probiotics. Given that microbial cells are inactivated during feed processing, they are not normally included in feeds but are rather added later to granules as a coating layer. The consequences are imprecise dosage and erratic delivery. In this regard LifeBioencapsulation SL has obtained excellent results in the delivery and dosage of live microorganisms through a patented preparation intended for oral administration in fish, based on the use of inert capsules. This product clearly improves oral delivery of live microbes compared to the usual methods. The capsules were created to deliver probiotic microorganisms (although they can also include prebiotic and nutraceutical substances) which are protected from both the chemical and enzymatic digestive physiological barriers during their transit through the stomach and intestine of the fish. Thus, the protected microorganisms maintain their integrity and viability and they can exert their biological effects after being released in later sections of the digestive tract. Capsules might be administered on their own, apart from feed, provided that their size can be specifically adapted to each stage of development. However, and depending on the nature of the substances added, capsules can also be further introduced into fish feeds, providing resistance to processing as well as a precise dosage without interfering in the feeding routine of the fish farm and consequently minimizing fish stress. LifeBioencapsulation SL is a Universidad de Almería spin-off recently awarded with prizes for the best project company and for the best business idea in AgriFood research by Campus de Excelencia Internacional Agroalimentario (ceiA3, Spain). The company was created with the aim of meeting the specific requirements of aquaculture nutrition. LifeBioencapsulation SL is made up of a group of researchers with extensive experience in animal nutrition and oral delivery of bioactive molecules of interest in aquaculture. The company has developed different encapsulation methods that offer quite unique solutions to specific problems. Through the utilisation of different polymers and protocols, LifeBioencapsulation SL manages to adapt the formulation of each capsule to each specific substance to be delivered, and to each growth stage of the animal. Consequently, the company offers encapsulation ‘à la carte’, providing services designed to specific requirements in aquaculture. The needs of each client are unique and therefore our products are also. In addition to this versatility in developing innovative products our company can manufacture small quantities on an experimental scale. Consequently, limited amounts of several experimental diets, including multiple factors at different concentrations for small-scale studies can be prepared. After determining the most suitable formulation, the feed can be produced on a medium scale to satisfy greater experimental needs. lifebioencapsulation@gmail.com
digestive tract is an important factor in optimising fish feeds (Deguara et al., 2003). Intestinal enzymes are correlated with the nutritional status of fish, and their activities have been used as indicators of the digestive capacity of farmed fish (Alarcón et al., 1998). In fact fish are capable of modulating their digestive enzyme pattern in response to the feed source, quality and concentration of dietary nutrients (Santigosa et al., 2008). The use of Scenedesmus meal to replace fishmeal protein did not decrease the enzyme activities secreted into the intestinal lumen at any of the inclusion levels tested, albeit increased activities attributable to algae inclusion have been observed. For trypsin activity, which plays a decisive role in dietary protein hydrolysis and zymogen activation, fish fed on SC12 showed significantly higher activity than those animals fed on a microalgae-free diet. In addition, alkaline phosphatase and L-aminopeptidase activities increased significantly in the SC20 group compared to the Control and SC39 groups (Fig 1). Nevertheless, total alkaline protease, chymotrypsin and α-amylase activities remained unaffected by Scenedesmus inclusion. Zymograms carried out on intestinal extracts obtained
12 | INTERNATIONAL AQUAFEED | January-February 2015