Probiotics are live microorganisms that are beneficial to their hosts, one of which is fish. Probiotics are dietary supplements in the form of microbial cells for fish that can inhibit the growth of pathogenic microorganism populations. The administration of probiotics can help maintain the quality of pond water in fish farming, prevent, and overcome fish disease attacks because it can inhibit the growth of pathogenic bacteria such as Aeromonas bacteria, and improve feed efficiency. Fish growth is influenced by the work of the digestive tract in absorbing nutrients, this is due to the help of the activity of enzymes amylase, protease, lipase, and cellulase (Warman, 2020). The problem of feed efficiency in the world of fisheries is that the price of feed basic materials is getting higher and difficult to obtain. This general problem is also felt by the Association of Farmer/Pond Groups (GAPOKTAN) in several regions in Indonesia. Muntafiah (2020) stated that the high price of feed comes from the use of factory feed raw materials which are imported commodities, causing large costs for fish farmers. Quality feed has complete nutritional content, is easy for fish to digest, and does not contain substances that are harmful to fish. Adinugroho et al. (2014) state that feed can meet the energy needs for fish to live and grow. The quality of feed can affect the use of feed by fish, both in terms of nutritional content and the level of digestibility of feed so that it can reduce ingredients that cannot be digested properly. Iribarren et al. (2012) stated that the use of probiotics is an internal solution to produce optimal feed growth and efficiency, reduce production costs, and ultimately reduce environmental burden due to waste accumulation in waters.
Keywords: Aluminium Alloys, Plasma Spray, Thermal Barrier Coatings, Thermal Fatigue, Yttria-Zirconia.