ALBERT

Description: Protection authorities of plant and animal genetic resources and conservation of biodiversity as national assets by using biotechnology techniques is the most important objectives of genetic data information bank. Establishment of shrimp species genetic data bank, makes possibility of study multiple genes such as economic genes and since knowledge of genetic variation within and among populations and barcoding species of shrimp are very important for species conservation and with so little researches of Asia in the global studies of DNA barcoding and animal taxonomy in Iran, In this study, Iran shrimp genetic diversity and genetic data bank was done. DNA barcode is a short, standard well known sequence of cytochrome oxidase І gene. By using this DNA sequence can be realized that each animal, plant or fungus belongs to which species. Also prepare a bank of genetic data shrimp pathogens and maintenance of these strains are steps to advance future researches in the fields of pathogenesis mechanism of pathogens, diagnosis, treatment, Disease prevention, production diagnosis native kits and detection of emerging and reemerging diseases its origins. So in this plan samples were collected from imported cultured shrimp Litopenaeus vannamei and and 6 Persian Gulf and Oman Sea shrimp species which classified based on traditional systematically as: Penaeus semisulcatus, Fenneropenaeus merguiensis, Metapenaeus affinis, Parapenaeopsis Stylifera and Fenneropenaeus indicus. After examination of DNA barcode sequence, molecular and bioinformatics operations of each sequence in the Consortium for the Barcode of Life (CBOL) and National Center for Biotechnology Information (NCBI), phylogenetic analysis of each sample was determined and similarity of each sample with NCBI and CBOL database was checked and the closest species to each sample were specified. According to the results different samples of L. vannamei, . banded P.semisulcatus, F. merguiensis and F. indicus have more than 97% similarity to the same species of other countries. non banded P.semisulcatus had 80.07% similarity to banded P.semisulcatus, M. affinis samples had 90.3% similarity to Metapenaeus ensis and Parap. Stylifera had 93.44% similarity to Parapenaeopsis coromandelica in the CBOL. This funding confirmed the need for further investigation and possible announcement of new species. By using ribotyping technique, native isolated pathogenic bacteria and fungi were identified and recorded in the gene bank database center. During sampling of shrimp and water of Specific Pathogen Free shrimp center, 40 bacterial strains were isolated, which 8 of them had the most frequency and identification based on 16S rDNA sequencing was performed. Bacteria identified are: Vibrio nigripulchritudo strain IS013(GenBank:KP843725) ،Vibrio brasiliensis strain IS014 (GenBank:KR186076) ،Vibrio rotiferianus strain IS015 (GenBank:KR186077) ،Vibrio azureus strain IS012 (GenBank:KJ018724.1) ،Vibrio owensii strain IS016 (GenBank:KR186078) ،Agarivorans gilvus strain IS017 (GenBank:KR186079) ،Vibrio brasiliensis IS018 (GenBank:KR186080) and Vibrio alginolyticus strain IS019 (GenBank:1817854), which were recorded in The World Bank genes. In this study fungal isolates were not detected.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: Thirty to 40% of total fish catch is converted to waste. Using different methods of hydrolysis of the protein can be recovered of fish waste and increase the amount of protein efficiency. In this study, the four enzymes Alcalase , protamex , pepsin and trypsin were used for hydrolysis of four fish species including common carp (Cyprinus carpio) , silver carp (Hypophthalmichthys molitrix) , grass carp (Ctenopharyngodon idella) and the Big head (Hypophthalmichthys nobilis). The effects of pH, temperature and hydrolysis time on the rate of hydrolysis were studied on soluble proteins and degree of hydrolysis (phase I ). In the second step, proximate factors of peptone been evaluated and eventually replace commercial peptone media MRS ( Lactobacillus plantarum , Lactobacillus delberuki , Lactobacillus casei , Streptococcus thermophilus ) and TSB ( Listeria monocytogenes, two species of Bacillus and Pseudomonas, Streptococcus faecium) and the optical density of bacteria at different times were compared with control samples . Results showed that the highest degree of hydrolysis and soluble proteins were referred to alcalase and protamex, pepsin and trypsin respectively. The highest value of hydrolysis, in all treatments, was attributed to grass carp and silver carp, common carp and big head respectively. The best pH and temperature for alcalase, protamex, pepsin and trypsin 8.5and 55, 7.5 and 55, 3.5, 37, 7 and 37 respectively. Best time to achieve the highest degree of hydrolysis and soluble protein was 90 minutes. Qualitative analysis showed that the highest and lowest amounts of protein and fat in the treatment of alcalase (about 70 % protein and less than 0.5 % fat ) and protamex, pepsin and trypsin was then . The results of bacteria culture showed that the highest percentage growth of lactic acid bacteria was referred to Streptococcus thermophilus and Lactobacillus casei had the lowest rate of growth. In other bacteria, Pseudomonas and Bacillus species were the highest percentage of growth and Listeria monocytogenes and Streptococcus faecium respectively. In all treatments, alcalase had the best results and the peptone prepared from fish waste grass carp had the best condition for growth of used bacteria. It seems that the initial substrate , the parameters used such as temperature, pH, and enzyme hydrolysis time , have a significant effect on the quality of peptone and protein content in the final product is determined value of protein for culture of bacteria.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: The project of "Assessment of different methods of water treatment on decreasing pathogenic bacteria in shrimp hatcheries" achieved by mean of reviewing the effectiveness of various methods on the water treatment to reduce bacterial load of sea water. The project performed in Bandargah region of Bushehr province in order to checking the effect of different methods on the sea water and bacterial population. This project has been done over a year. In this study a total of 138 samples was collected during seven times and was evaluated as well as 7 treatments. In this study, the comparison of the effect of each factors (sand filter, chlorine, ultra violet ray, chlorine combined with ultra violet ray) was analyzed on the sea water by means of disinfection. During this study, other environmental factors such as water temperature, dissolved oxygen, pH and salinity was measured till we can ensure that they don’t have any negative impact on the treatments. Results showed that the density of total bacteria in sea water (Control) was averagely 5187 CFU/ml, this was done while the total density of bacteria in the sea water, reservation pool sample, sand filter water, water that irradiated with ultraviolet rays, chlorinated water and the water that was influenced by both chlorine and ultra violet ray was respectively 5187 2137, 4449 2042, 2782 1335, 1164 692, 143 104, 87 76 CFU/ml. Therefore, reservation pool, sand filter, ultra violet ray, chlorine, chlorine-ultra violet ray each of them was reduce respectively 14, 46, 77, 97, 98 percent of the density of total bacteria or in other words they reduced 0.06, 0.27, 0.65, 1.56, 1.77 log of the total population of bacteria in water. Moreover, the results from the total count of vibrios showed that reservation pool, sand filter, ultra violet ray, chlorine, chlorine-ultra violet ray each of them was reduce respectively 17, 47, 74, 98, 99 percent of the density of total vibrios or in other words they reduced respectively 0.08, 0.27, 0.59, 1.66, and 1.95 log of the total population of vibrios in sea water. Also the bacteria that isolated from each treatment were identified with the use of biochemical methods that totally were includes a wide range of bacteria, the identified vibrios were: Vibrio alginolyticus, V. costicola, V. fischeri, V. fluvialis I, V. fluvialis II, V. harveyi, V. natriegens, V. nigripulchritudo, V. parahaemolyticus, V. plagius I, V. vulnificus, V. anguilarum I, V. campbellii, V. nereis, V. proteolyticus, V. splendidus, and Unknown V. spp. Other identified bacteria belonging to the following genus: Acinetobacter, Aeromonas, Alcaligenes, Bacillus, Borkholderia, Eschricia, Enteroacter, Flavobacterium, Micococcus, Proteus, Pseudomonas, Serratia, Staphaphylococcus, Streptococcus, and Unknown Bacteria spp. By comparing the results, we concluded that the best result was related to treatment that the sea water had been disinfected after the combined effects of chlorine and ultraviolet ray. It was determined that this process in compared with other treatments, had been reduced the total number of bacteria, the total number of Vibrios, the number of sucrose fermentative vibrios, and the number of non-sucrose fermentative vibrios respectively 98, 99, 98, 99 percent. In other words, the number of bacteria was reduced respectively 1.77, 1.94, 1.82, 2.23 log. So in this study, the applied method was introduced as the most effective way of disinfecting sea water. Meanwhile, none of pathogenic bacteria for shrimp including Vibrio harveyi was isolated by using this treatment. Comparing the results showed that the combined effects of chlorine and ultraviolet radiation is the most effective applied method for disinfecting sea water.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: At present, the aquaculture industry to provide proper instructions in the field of health management, including production of Specific Pathogen Free shrimp (SPF), require sensitive and reliable methods for the detection and identification of pathogenic microorganisms. Molecular methods which used in the detection of microorganisms have a high discriminatory power in the taxonomy and in relation to libraries in the world. On the other hand, the accurate identification of microorganisms, providing the genetic data bank of shrimp pathogens and maintenance of these strains is the step to promote further research on the mechanisms of pathogenesis of pathogens, diagnosis, treatment, prevention of disease, identify indigenous production kits, diagnosis re emerging and emerging diseases and their origin. Therefore, in this project, by using ribotyping technique, native isolated pathogenic bacteria and fungi were identified and recorded in the gene bank database center. During sampling of shrimp and water of Specific Pathogen Free shrimp center, 40 bacterial strains were isolated, which 8 of them had the most frequency and identification based on 16S rDNA sequencing was performed. Bacteria identified are: Vibrio nigripulchritudo strain IS013(GenBank:KP843725), Vibrio brasiliensis strain IS014 (GenBank:KR186076), Vibrio rotiferianus strain IS015 (GenBank:KR186077), Vibrio azureus strain IS012 (GenBank:KJ018724.1), Vibrio owensii strain IS016 (GenBank:KR186078), Agarivorans gilvus strain IS017 (GenBank:KR186079), Vibrio brasiliensis IS018 (GenBank:KR186080) and Vibrio alginolyticus strain IS019 (GenBank:1817854), which were recorded in The World Bank genes. In this study fungal isolates were not detected.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: This project investigates bacteria effects as probiotics on growth and survival rate and resistance of shrimp during propagation stages. Bacterial flora were extracted from seawater , water of cultured farms , shrimp cultured and sludge from private propagation farms different bacteria such as Vibrio alginolyticus(serotype1-4) Vibrio splendidus I , Vibrio fluvialis ,Vibrio anguillarum ,Vibrio costicul, Vibrio vulnificus,Vibrio nereis,Vibrio camplbelli,Vibrio natriegens,Vibrio proteolyticus, Vibrio plegius ,Vibrio fischeri,Aeromonas hydrophila, Aeromonas schuberti,Aeromonas salmonisida, Aeromonas veronii , Pseudomonas pseudoalcaligenes, Pseudomonas chloraphis, Alcaligenes faecalis, Bacillus megaterium, Bacillus pumilus, Bacillus circulans, Bacillus cereus, Bacillus subtilis, Bacillus licheniformis, Lactobacillus case, Lactobacillus bulgaricus, Lactobacillus delbrukii, Lactobacillus fermentum, Lactobacillus leichmanii, Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus acidophilus, Lactobacillus lactis, Pediococcus acidilactici were isolated , identified and lyophilized.These bacteria in different experiments were used on shrimp life cycle stages and live food such as Chaetoceros , Skeletonema and Tetraselmis algae. Some serotypes of one bacterial species showed various reactions in media and experiment probiotics. Vibrio alginolyticus(serotype1) with 107 cells/ml can increase Tetraselmis sp production during 6 days to 71% compared to the control experiment without bacteria. Also Vibrio alginolyticus(serotype4) with 105 cells/ml can increase Tetraselmis spp production during 6 days to 389% more than control. Vibrio splendidus could increase 23% shrimp fork length in postlarvae 3 compared control. Vibrio alginolyticus+ Vibrio fischeri can increase survival , fork lenght and body weight of green tiger shrimp postlarvae significantly(P〈.05).

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: Streptococcosis is an infectious bacterial disease that causes huge economic losses in cold water aquaculture industry. Disease outbreak was experienced in some of provinces farms in recent years. Fars Province, has produced 7,000 tons of cold-water fish. According to Streptococcosis report in 1381 from the province and Proceedings have been performed during 10 years against disease and also economic losses impact of disease on rainbow trout production, risk assessment of Streptococcosis conducted on the plan. In this study, of 586 sick fish (have symptoms) studied 230 fish (39.24%) Streptococcus and (26.62%) gram negative bacteria were isolated. Of 754 healthy grower fish and fry (with no clinical signs) 10 fish or fry (1.32%)infected with streptococcus and 60 fish or fry(7.95%) infected with gram negative bacteria (Yersinia ruckeri , Pseudomonas , entrobacteriaceae).According to biochemical tests and molecular examinations , isolated Streptococcus identified as Lactococcus garvieae , Streptococcus iniae and Streptococcus sp. Furthermore some physical and chemical parameters measured and aerobic bacteria of selected farm water counted. These factors effects on disease incidence and changes were evaluated by applying logistic regression.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: Bacterial flora and parasitic fauna of M. leidyi an exotic invader jelly fish to Caspian sea ecosystem and B. ovata to Black sea an alternative biological control agent was studied. During summer 1382 to spring 1383, using routine Bacteriological work. 72 sample of sea water Caspian sea obtained from depth 20 and 50 meters, 36 sample of M. leidyi from depth 20 meters , 10 sample of B. ovata and 3 sample of sea water (Black sea ) were collected and according to Bacteriological was studied. 216 sample of M. leidyi from depth 10 to 50 meters of Caspian sea and 47 sample of B. ovata from Black and Marmarreh sea (turkey) were collected and was studied. In this study no parasite from was identified in M. leidyi (Caspian sea) but 64 percentage and 73 percentage of B. ovata (Marmarreh and Black sea respectively) contaminated to Trichodina ctenophore at varians concentration B. ovata of Black sea (130 min 1050 max) and B. ovata Marmarre sea (420 min 2100 max). while B. ovata kept at high salinity of 21 ppt was more contaminated with this pretrichial protozoan(Trichodina) than in low salinity (12/5 ppt). in comparision of bacterial flore in two cetenophore (M. leidyi and B. ovata) was observed that some of bacteria such as micrococcus sp, Aeromonas sp. Bacillus coagulans in both ctenophore and some other bacteria such as Agromobacterium and chromobacterium only observed in B. ovata but other researcher have reported fram Caspin sea and some of bacteria to specific Shewanella , Vibrio harveiy and bacillus linens was observed in B. ovata . of course specific bacteria can not transfer to Caspian sea (different of salinity black sea (2/1%) to Caspian sea (1/25 %)). Therefore if B. ovata to introduce to south Caspian sea for biological control population M. leidyi. it is necessary at first some of viral pathogen in aquatic animal (fish) such as VNN, IPN,IHN,VHS,SVC was studied and then with confidence 95% non infestation B. ovata to viruses and pass from bath anti parasite and anti bacterial must be introduce to south Caspian sea.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: In recent years, according to increase in consumption of fish in the world, however, due to the lack of control of many common diseases with disease-causing pathogens, the total world production of fish has decreased. Rainbow trout (Oncorhynchus mykiss) is one of the most preferred species in aquaculture of Iran. Development of an economical artificial to accelerate the growth and to maintain the health status of this fish is of major importance for sustainable rainbow trout culture. Fish diseases are a serious threat to economic viability of any aquaculture practice. Currently, the commercial aquaculture industry prefers to reduce the costs of production. Because the cost of antibiotics used for prevention and treatment of diseases, and excessive use of growth hormones for improving growth performance is very high. However, the development of antibiotic resistant bacterial strains, accumulation of residue in cultured fish and environmental problems associated with the use of chemicals have led to investigate on suitable methods of disease management. Therefore, a new approach to immunotherapy is actively used to prevent or treat fish diseases, increased disease resistance, feed efficiency and growth performance of fish in a sustainable aquaculture industry. In this regard, extensive research has been carried out to test the new compounds led to the development of the aquaculture industry. It has been proved that use of medicinal herbs in fish diet enhance the immune system against infections with various bacteria, especially, Aeromonas hydrophila in different species of fish, which is of the major bacterial pathogens, leading to heavy mortality rate and decrease the productivity efficiency, causing high economic loss of the fish farmers. The present project “the use of development medicinal plants in Aquaculture” with 4 separate sections reveled their results as follows: Part one: In this study, Origanum vulgare, Aloe vera extracts and placebo (70 % lactose, 10 % starch and 20 % talc) were used at a rate of 1% and levamisole at a rate of 0.1% of weight feed at a rate 2% of body weight.In conclusion, dried Origanum Vulgare and Aloe vera extracts at a rate of 1% of weight feed increased specific and non-specific immune systems in rainbow trout (13 and 2 gram) in identical weeks (2, 4, 6, 8 and 10). Therefore, these extracts can use to enhance immune system in aquaculture industry. Part two: In this study, some non-specific immune responses, hematology and biochemical parameters in rainbow trout juveniles (16 gr mean weight) and their resistance to Streptococcus iniae were evaluated following oral administration of Echinacea purpurea and Astragalus sp. extract. Three concentrations (0.5, 1 and 1.5 gr/kg of feed) of Echinacea purpurea and three concentrations (2, 3 and 5 gr/kg of feed) of Astragalus sp extract and control group were used for 60 days. Parameters evaluated included: levels of C4, C3 (complement components), free oxygen radicals (respiratory burst), Lysozyme, numbers of lymphocytes, monocytes and neutrophils. In the end, the relative survival rate (RSR) of fish was evaluated against S. iniae. The results showed that the levels of C3, lysozyme, oxygen free radicals, the number of neutrophils and lymphocytes in the experiment groups (the highest dose) compared to control group were increased significantly (p 〈0/05). While, the values of C4 and number of monocytes compared to the control group were not significantly different (p〉 0.05). The relative survival rates of fish following challenge with Streptococcus iniae, were 91/11, 93/33 and 44/44 percent in experiments (Echinacea purpurea and Astragalus sp.) and control groups, respectively. In conclusion, it may be state that Echinacea purpurea and Astragalus sp. extracts enhance the non-specific immune system and fish resistance against Streptococcusis, and it seems it can be used as immunostimulant in feed. Part three: Today, regarding the development of sturgeon rearing and importance of the aquatic health, it is necessary to apply natural material to combat pathogenic factors. Therefore, using medicinal plants is an excellent alternative instead of chemical material to control pathogenic factors. As, protozoan ectoparasites are one of the most important factors which have threatened sturgeon life, so this study carried out to determine lethal concentration of garlic (Allium sativum) and Zataria multiflora hydroalchoholic extracts on fingerlings of Persian sturgeon (Acipenser persicus) that the efficiency and the effective dose of theses extracts determined for controlling protozoan parasite naming Trichodina. Then, considering the results of the mentioned experiments, the study conducted on effective concentrations (EC50) of these extracts to combat Trichodina protozoan parasite. In this study the concentration of Zataria multiflora hydroalchoholic extract for final experiments was 200 to 600 mg/L. Therefore, it was determined for the first time that Zataria multiflora extract can be effective to combat Trichodina. The EC50 of Zataria multiflora extract for 1h bath is 437.62mg/L. Moreover, the concentration of garlic hydroalchoholic extract for final experiments set at 50 to 400 mg/L and the EC50 of garlic extract is 172.58 mg/L for 1h. In experiments of EC50, the differential counts of white blood cells (WBC) showed no significant difference in numbers of lymphocytes, monocytes and neutrophils in different treatments (P〉0.05). But there is significant difference in numbers of eosinophils in different treatments (P〈0.05). During the experiments of EC50 for garlic and Zataria multiflora extracts, no abnormal behavior observed in Persian sturgeon fingerlings which indicates that these extracts have not created stressful and irritable conditions. The final effective time for these extracts to completely eradicate Trichodina by garlic hydroalchoholic extract is less than 3h in 172.58 mg/L (EC50). But, for Zataria multiflora hydroalchoholic extract, it is less than 5h in 437.62 mg/L. The results showed that in all treatments of garlic hydroalchoholic extract, Trichodina eradicated completely from gill and skin of Persian sturgeon fingerlings during 9h. This time for Zataria multiflora hydroalchoholic extract is 12h. The results of this study showed that garlic and Zataria multiflora hydroalchoholic extracts with EC50 of 172.58 and 437.62mg/L, have categorized in low toxicity materials which are suitable to be replaced with chemical materials. This investigation showed that the therapeutic index of garlic hydroalchoholic extract is 73.15 that found to be more than Zataria multiflora hydroalchoholic extract (22.69). So, regarding this index, garlic hydroalchoholic extract is more healthful. Considering the results of this study which indicates the health of these herbal extracts, applying medicinal herbs can be emphasized as a suitable material to be replaced with chemical ones. Part four: In order to investigate the effect of ethanol extracts of garlic (Allium sativum) and Zataria multiflora on Aeromonas hydrophila bacteria Persian sturgeon (Acipenser persicus)took the kids to the isolation and identification of bacteria , the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of bacteria Aeromonas hydrophila by garlic (Allium sativum) and Zataria multiflora hydroalchoholic extracts to determine the lethal concentrations of hydroalchoholic extracts of garlic (Allium sativum) and Zataria multiflora hydroalchoholic extracts on Persian sturgeon (Acipenser persicus)children , and also to evaluate the efficacy and determine the effective doses of the bacterium Aeromonas hydrophila extracts of in vitro and in vivo were measured . Due to the absence of the Aeromonas hydrophila identification by molecular country in the study of bacteria isolated from sturgeon disease is suspected after detection by screening DNA extraction and molecular By toward action and results by NSBI Aeromonas hydrophila bacteria and Authentication Code NSBI was recorded in Gen Bank JX987090 . Based on studies done in vitro (in vitro) in this study, the minimum inhibitory concentrations (MIC) Aeromonas hydrophila bacteria by extracts of garlic and thyme and arrange 1 mg/ml, 0.25mg/ml and the minimum bactericidal concentration (MBC) of bacteria Aeromonas hydrophila by the extracts, respectively , and 2mg/ml, 0.5mg/ml. Study on the pictures taken out from sections of gill, liver and kidny of Persian sturgeon fingerlings (Acipenser persicus) showed that in different doses of garlic (Allium sativum) and Zataria multiflora hydroalchoholic extracts the teretment grups were examined and some microscopic damages observed. They are hyperemia, adhesion in the gill filaments, cell necrosis, melanin pigments in gill primary filaments, cloudy swelling of hepatocytes, liver necrosis, hyperemia and increase in melanin pigments and melano macrophage centers in liver, glomerular changes such as congestion and blocked the dilation of Bowman's space , bleeding, cell necrosis , cloudy swelling of the in kidney.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: The aim of this study was comparison the effect of cow dung as organic fertilizer and chemical fertilizer on microbial flora, fish and human pathogenic bacteria and physico-chemical parameters of cyprinus fish pond water. The water samples were collected from two ponds, pond 1 was fertilized by cow dung and pond 2 was fertilized by chemical fertilizer, respectively from May to October 2011. . The aerobic and anaerobic bacteria were enumerated in TSA by serial dilution of the sample, followed by conventional pure plate method. Coliforms bacteria were similarly isolated on Chrom agarTM ECC. Moreover, the water samples were used to analysis of BOD, dissolved oxygen, conductivity, transparency, total alkalinity, total dissolved solid, total hardness, total nitrogen and total phosphorous. Temperature and pH were measured by thermometer and portable pH meter in place of ponds. For isolating of fish and human pathogenic bacteria, thirty six fish were collected from pond 1 from July to October and then sampled from their liver and kidney and inoculated in blood agar. The mean of total count of bacteria and total coliform count in cow dung sample were 4 × 104 ± 1200 and 4700 ± 300 CFUmL-1 respectively. The mean of water total count bacteria of pond 1 were significantly higher than the water of pond 2. The water total count bacteria of pond 1 were significantly increased in August, but water total count of pond 2 was not shown significant variation from May to October. The results showed that Pseudomonas, Klebsiella, Enterobacter, Yersinia and E.coli were isolated from water of pond 1 but just Pseudomonas and E.coli were isolated from water of pond 2. Moreover, the human pathogenic bacteria shuc as Shigella and Salmonella were not isolated from of water and fish samples from pond 1. In this study, the bacteria growths were negative in all of the inoculated plate from fish liver and kidney. The total hardness, total phosphorus, total dissolved solid and conductivity of the pond 1 water were significantly higher than the pond 2 water. But the BOD, dissolved oxygen and transparency of the pond 2 were significantly higher than the pond 1 water. There were no significant differences in the total nitrogen, total alkalinity and pH between water of pond 1 and 2. In recent years, the chemical fertilizer has been used in cyprinus fish pond but many studies have showed that they were high risked as environmental pollution. Thus, the use of livestock manure especially cow dung could be a suitable alternative. The results showed the use of cow dung increased the bacterial population and diversity. Increasing of bacteria population caused increased total phosphorus that plays an important role in bloom of plankton because we found decreasing transparency and planktons are an important food for cyprinus fish. In despite of isolation of fish and human pathogenic bacteria from water, the bacteria growths were negative in all of the inoculated plate from fish liver and kidney. In summary, it seems the cow dung is a suitable alternative for fertilizing of cyprinus fish pond water if a microbial and physico-chemical monitoring of fish and pond water were continuously arranged.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: Nisin is a natural antimicrobial and has inhibitory effect on the pathogens and spoilage organisms. The efficiency of nisin reduced after reaction with food compounds. There is the hypothesis that combination of nisin with organic salt increases the shelf life of fish. The purpose of this study was mainly to evaluate the effects of nisin (0.15 %) and sodium acetate ( 1% ) individually and in combination on shelf life of fillets and whole trout ( without viscera). then, the behavior of Listeria monocytogenes and Clostridium botulinum type E were evaluated in different time at 40C. Physical and chemical parameters including: pH, Peroxide Value (PV), Tiobarbithoric Acid (TBA) and Total Volatile Nitrogen (TVN) and bacterial factors such as Total Viable Count (TVC), Pscycrothophic Count (PTC) and Lactic Acid Bacteria (LAB) were examined. These parameters were done at intervals of 4 days for 16 days. Results showed that chemical and bacterial factors of whole trout (Oncorhynchus mykiss) ( (without viscera) have been more favorable than the fillets . It also showed that the peroxide value , the thiobarbituric acid, volatile nitrogen bases , and pH in combination of sodium acetate and nisin Z treatments were exposed to significantly compared to control treatments ( no preservatives ) (P〈0.05). Treatments with sodium acetate and nisin Z (individual ) were exist after combination treatment. Hence it can be concluded that the maximum shelf life of in preservative treatments was 16 days , but control treatment was 12 days in some cases and in some cases 16 days. Effects of treatments on Listeria monocytogenes and Clostridium botulinum in the control treatment showed the highest growth was observed in both species ( log 8 ) but in single and combined treatment of bacterial growth slower , but is still the trend the 16th day of so Listeria and Clostridium log 5 to log 6 , respectively. Vegetative cells of Clostridium were more sensitive in compare to Listeria. When using preservatives (chemical or biological) in fish tissue, parameters such as the type of preservative, used method, pH, proteolytic enzymes, the incidence of resistant strains and so on influence of antimicrobial agents used. The overall conclusion of the study was shelf life of whole trout (without viscera) was more than fillets, combination of nisin and sodium acetate were better than other treatment and finally higher doses of bilogival preservatives are need to for achieve to significant reduction of pathogenic bacteria .

Description: Iranian Fisheries Science Research Institute

Description: Published