Presentation on theme: "Probiotics in fish culture: immunomodulatory and ecophysiological responses ● 期刊 :Fish Physiol Biochem ● DOI 10.1007/s10695-013-9897-0 第八組 : 組員 :4a1h0013."— Presentation transcript:
Probiotics in fish culture: immunomodulatory and ecophysiological responses ● 期刊 :Fish Physiol Biochem ● DOI /s 第八組 : 組員 :4a1h0013 薛瑋均 4a1h0101 郭筱茹 4a1h0016 黃造培
Abstract Aquaculture is emerging as one of the most viable and promising enterprises for keeping pace with the surging need for animal protein providing nutritional and food security to humans,particularly those residing in regions where livestock is relatively scarce.
Abstract Conventionally, the disease control in aquaculture has relied on the use of chemical compounds and antibiotics. The development of non-antibiotic and environmentally friendly agents is one of the key factors for health management in aquaculture.
Introduction What is Probiotics ? A bacterial supplement of a single or mixed culture of selected non-pathogenic bacterial strains is termed probiotics. Probiotics as ‘a live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance
Currently used in aquaculture probiotics, its main features include the following: 1. Increase nutrition and improve feed digestibility Fish gut produces digestive enzymes with specific microorganisms can enhance digestion and absorption of feed may also be of intestinal sources of vitamins and essential amino acids
Currently used in aquaculture probiotics, its main features include the following 2.Irritating or cellular immunity Some probiotics can stimulate aquatic organisms nonspecific immunity (nonspecific resistance) ex: 桿菌（ Bacillus sp. ）可激活草蝦的免疫系統 3.antiviral Currently the antiviral mechanism of probiotics is not clear, but many studies have shown that probiotic substances or extracts produced virus can cause passivation ex: 在鮭魚卵巢分離出的 Pseudomonas sp. 、 Vibrio sp. 、 Aeromonas sp. 及 Corynebacterium sp.
Currently used in aquaculture probiotics, its main features include the following 4.Improve water quality As the main features of probiotic bacteria because bacteria can affect the composition of the class of microorganisms in water and reduce the number of pathogens, and can improve water quality. The principle is the Gram-positive bacteria can be effectively converted to carbon dioxide organics
Common probiotic introduction 枯草桿菌 (Bacillus subtilis) Single cell 0.7 ~ 0.8 × 2 ~ 3 m. No capsule, Zhou flagella, are Gram-positive bacteria. Is a kind of aerobic bacteria. 特性： 1. Can withstand temperatures of -60 ℃ to +280 ℃ 2. Breed quickly, 4 to 6 hours to 10 times proliferation 3. Absorbent containing gum, moisture and strong 4. Organic matter decomposition and strong, able to break down large molecules into smaller molecules.
Common probiotic introduction 5. Metabolites enzymes, organic acids, very rich 6. Alkali resistance, high gas and low gas has strong antibacterial antagonism. 7. Can have the stench of decomposing organic sulfur compounds, organic nitrogen, can deodorize
Nitrifying bacteria growth environment 1. Temperature ： Nitrifying bacteria suitable temperature of about 20 to 28 degrees c, the optimal growth temperature of about 25 degrees and reproduction c. General nitrifying bacteria at temperatures below 5 degrees c and above 42 degrees c to stop metabolism 2. Light ： Unlike the nitrifying bacteria and certain proprietary green photosynthetic bacteria generally have photosynthetic pigments, and therefore can not take advantage of the sun for photosynthesis in organic synthesis. Not only can not take advantage of the sun, but? Afraid of sunlight 3. Substrate ： Nitrifying bacteria much needed sediment, but the difference is that it's not intended for food, but sediment can provide attachment, shelter and access to a source of ammonia and nutrient sources they need. Not for breeding, and can not benefit ammonia source and a nutrient source for many of nitrifying bacteria is not found before the end of the appropriate quality.
Nitrifying bacteria growth environment 4. Water ： Since the characteristics of sessile nitrifying bacteria living resources must rely on water transport oxygen, ammonia and nutrients, such as it needs. 5. DO ： Oxygen is an essential element of life nitrifying bacteria. Advice is not less than 2ppm. 6. Ph value ： Generally, most prefer nitrifying bacteria grow in weakly alkaline in the ring, the ph value of about 7.5 to 8.2. ph value will affect the growth and reproduction of nitrifying bacteria. Nitrite bacteria ph range of 7.0 to 8.0, the optimal average of 7.8. Nitric bacteria from about 6.5 to 8.5.
Nitrification system to establish instances Day 1~7 Buy two or three more resistant to raising fish, feed a small amount of feed. Next day to start measuring the concentration of ammonia. Concentrations will continue to rise for several days Day 7~14 About a week or so, because the nitrifying bacteria grow into, began to enter the medium term. Concentration of ammonia will quickly subside. During this period, if the fish in poor condition, a small amount of water changes to dilute the tank of water. Relative, nitrite concentration started to climb a week later, and ammonia test synchronization, start testing nitrite. amount once every two days, nitrite will reach the peak and then decline slowly
Nitrification system to establish instances Day 17 Began in the later stages. Another one week, when nitrite and ammonia concentrations are reduced to zero, nitrate concentrations began to increase this time, congratulations greatly. Systems created. Additional fish do not rush. First change a small amount of water. then wait two days plus fish. than once and do not add too much. otherwise add too much at once, the system will collapse. efforts made three weeks ago on the East into water.
Nitrifying bacteria growing 1. Slow period ： When new to nitrifying bacteria living substances, growth lines to adapt to the new environment without increasing the number of periods of nitrifying bacteria. The length of this period, depending on the extent of the impact the new environment of nitrifying bacteria may be. 2. Logarithmic growth phase ： After the bacteria adapt to the new environment, rapid oxidation of ammonia or nitrite to obtain a fixed period of inorganic carbon energy, thus accelerating the reaction of organic synthesis, the number of surge is the logarithmic growth phase, the growth of the cover into the case-based progression increases. At this stage, the reproductive rate of up to the maximum.
Nitrifying bacteria growing 3. Decreasing Growing ： When ammonia or nitrite concentration gradually reduced to a point where the nitrifying bacteria, the remaining resources will limit the growth rate of growth of nitrifying bacteria, so increasing the number of nitrifying bacteria, it becomes very slow period. 4. Resting ： Nitrifying bacteria grow in the environment is limited impact factor (such as insufficient source of ammonia) has reached saturation, where growth rate is equal to the death rate has been the number of nitrifying bacteria to reach a stable state. Due to the relatively short resting, so it was omitted to distinguish this period.
Nitrifying bacteria growing 5. The breath of ： Also known as endogenous period. Ammonia or nitrite in the system have been exhausted, the nitrifying bacteria was "hungry" state, only to continue the use of in vivo metabolism of nutrients, the death rate is greatly increased, greatly reducing the number of periods.
Conclusion ● Characteristics of probiotics in aquaculture applications include: improved nutrition and increased feed digestibility, stimulate or enhance cellular immunity, thus competing with pathogenic bacteria exclusion, improve water quality and resistance to viruses and other probiotics, but now most of its mechanism of action is still is not clear, so the selection of probiotics, it is necessary to determine the host harmless.