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  This study aimed to investigate the quality of effluent water of a large shrimp farming complex in Chabahar region in Sistan and Baluchestan province (Iran). Fifteen sampling stations were designated in three distinct areas of these farms i.e. the water supply canal, the drainage canal and the receiving area of the farm effluents in Gwatar Gulf. Water samples were taken from June to December 2004 for measurement and monitoring of nitrate, nitrite and ammonia compounds. The results revealed that the shrimp farms effluents have a profound effect on the water quality and aquatic environment of the drainage canal and the Gwatar Gulf. The average concentration of nitrate, nitrite and ammonia remained considerably higher in the drainage canal and Gwatar Gulf compared to the supply canal throughout the study. The amount of these compounds increased considerably in the drainage canal during the final stages of culture period and in Gwatar Gulf at post monsoon. The results of one way analysis of variance (at P<0.01 level) showed that all physical and chemical factors except water temperature were significantly different between stations. Considering that more than 25% of the shrimp farms of this complex were active during this study the measured values of nitrate, nitrite and ammonia compounds in the effluents were at the optimum range recommended for the shrimp farms.

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Fish Protein Concentrate (FPC) is a healthy, sustainable and high nutritive product that produced from fish and protein and other nutrients are more concentrated than in the fresh fish. The aim of this research is to study the sustainability of FPC produced from Kilka (combination of three Caspian Sea Kilka species, Clupeonella engrauliformis, C. grimmi and C. cultriventris which were not identified and processed separately) in VP (Vacuum Packaging) and MAP (Modified Atmosphere Packaging) at different temperatures during six months of storage. According to result of chemical analysis performed, protein content was evaluated 91.2%, lipid 0.5%, ash 3.6%, moisture 2.3%, TVN 10 mg/100g and peroxide 5 meq/kg in the produced FPC before packing. Amino acids and fatty acids were also determined. Lipid amount in FPC after 6 months at 35°C in VP changed from 0.50 to 0.45 and in MAP (combined of 60% CO₂, 30% N₂ and 10% O₂), decreased from 0.50 to 0.36. It was also detected that increase in temperature leads to more decrease in lipid content but it was not significant (P>0.05). Protein content of FPC has changed from 91.2% to 73.6% during six months at 35°C in VP and 69.4% in MAP. But at 5°C, protein contents were changed from 91.2% to 88.4% and 81.2% in VP and MAP, respectively these changes were significant (P<0.05) but the decrease in MAP was again more than VP.

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In this research the affect of A. hydrophila on pathogenesis of Crayfish A. leptodactylus was carried out. This study was designed in three groups as treatments and one group as control in triplicate with 20 Crayfish in each glass aquarium. The treatments have exposed to A. hydrophila. The concentrations of the bacteria in treatments were      , and   CFUmL^-1 respectively. The untreated control group was disinfected by oxytetracyclin at concentration of 100 ppm for 24 hours. The haemolymph samples were withdrawn for measuring of THC and TPC within interval hours (2, 6, 12, 24, 48, 96, 144, 240 and 336). The Crayfish samples were then fixed in Davidson fixative. The results showed that the differences of THC value between treatment 4 (95.33±23.16) and control (1.13±.45) were significant (P<0.05) as well as control and treatments 3 (35.33±16.16) and 4 (95.33±23.16) during 2 initial hours. In case of THC the significant difference (P<0.05) was observed between control group (72.33±15.04) and treatment 3 (13.13±5.85) after 48 hours. During 240 hours, also the difference of THC value between control group (80.33±24.94) with treatment 2 (14.67±3.51) was significant (P<0.05). The finding of TPP value showed that there was no significant difference between control group and treatments in during mentioned times (P<0.05). The result of histopathology in heaptopancreas and gill sections showed that hemocyte aggregation and necrosis within pyknosis of nucleus. In lower concentrations of bacteria no pathological changes of heart were observed. In digestive tract no changes were appeared in treatments, but in concentration of 3×10⁸ CFU ml^-1 a low aggregation of hemocytes was revealed.

 

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The study was undertaken to determine bacterial contamination of warm-water fish ponds and silver carps harvested from those ponds in Guilan province, Iran. In this respect, water samples were taken from 7 ponds and investigated by testing total bacteria, coliforms, and Escherichia coli. In addition, skin swab samples of silver carps caught from each pond were studied for enumeration of the same bacteria as well as Staphylococcus aureus and also for the presence of some human bacterial pathogens including Salmonella spp., Vibrio spp., and Listeria monocytogenes. For all bacteriological examination techniques of International Organization for Standardization were followed. Results showed that mean water bacterial quality in ponds was significantly different (p<0.01). About 43% of water samples were positive for E. coli, which indicates fecal contamination of some fish ponds. Bacteriological results of the fish harvested from ponds showed significant differences (p<0.0001) in total bacterial counts and coliform counts. However, counts of E. coli and S. aureus did not vary significantly (p>0.05) in different ponds. Results also showed that potential human pathogens were isolated from about 78.5% of fish studied. Out of five bacteria genera investigated, S. aureus, E. coli, V. cholera, and L. monocytogenes were isolated from 78.57%, 47.61%, 7.14%, and 4.76% of the fish samples, respectively. The Salmonella spp. and V. parahaemolyticus were not detected in fish samples during the study. The association of pathogenic bacteria among silver carps suggests that if fish are handled or prepared improperly it could lead to food safety hazards for consumers.

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Considering the ever increasing population and industrialization leading to developmental trend of humankind's life, we are hardly able to detect the toxins produced in food products using traditional techniques. In this technique, the production of molecular framework and polymer is done using meta acrylic acid monomers, which are formed via covalence connection between meta acrylic acid monomers (MAA) of white polymer. Here also hydrogenised connection between exotoxin amino acid and meta acrylic acid is made that would function as the selective absorption for that. Then in the second stage, based on the bacterial antibody connection to nanoparticle, a sensor was used. In this part of the research, as the basis for absorption for the recognition of bacterial toxin, medium sized silica nanoparticles of 10 nanometer in the form of solid powder were utilized with Notrino brand. Then the suspension produced from agent-linked nanosilica which was connected to bacterial antibody was positioned near the samples of distilled water, that were contaminated with Staphylococcus aureus bacterial toxin with the density of 10-3, so that in case any toxin exists in the sample, a connection between toxin antigen and antibody would be formed. Finally, the light absorption related to the connection of antigen to the particle attached antibody was measured using spectrophotometers. The results indicate that the molecular framework polymer sensor is capable of detecting up to the density of 10-3, but not lower than that, whereas using the second sensor, up to 10-4 of density is detectable. Additionally, the sensitivity of the sensors were examined after 60 days and the first sensor by the day of 28 and the second sensor by the 56 day had confirmatory results and started to decrease after those time periods

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This study examined the effects of feeding of two dietary probiotics on growth performance and feed utilization, intestinal colonization and related health criteria, biochemical parameters, hematological indices, and immune parameters and protection against Yersinia ruckeri in Oncorhynchus mykiss during a period of 56 days. The study included 3 groups:1(a control group of fish, 2) a group of fish fed with a basal commercial diet supplemented with 2 × 10⁶ CFU g^-1 Pediococcus acidilactici (PA-group and 3) a group of fish fed with a basal commercial diet supplemented with  2.5 × 10⁸ CFU g^–1 Enterococcus faecium strain IR5 (EF-group). Each group was run in triplicate. The PA-group and EF-group showed significant improvement with respect to WG, SGR, FCR, PER, lactic acid bacteria (LAB) (%) in intestinal, intestinal colonization (log CFU g–¹), survival (%), RBCs, WBCs, hematocrit percentage (Hct %), and respiratory burst activity (RBA) levels, each of which was significantly higher than that in the control group (p<0.05). The WG and PER in the EF-group were significantly higher than that in the PA and control groups (p<0.05). Levels of immune-system response across a variety of measures, some of the measured hematological indices, LAB (%) in intestines, and survival rate (%) were higher in the PA group than that in the EF group on 56th days of feeding. Mortality in the PA group (20%) and EF group (33.3%) were significantly lower compared with that in the positive control (73.3%) during the 10 days following exposure to Y. ruckeri (p<0.05).

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The effects of Caper (Capparis spinosa L.) extracts on microbiological, chemical and sensory changes of rainbow trout (Oncorhynchus mykiss) fillets stored at 4 ˚C were evaluated. Trout fillets were dipped in Caper extracts (0.2 and 0.5%), packaged with or without modified atmosphere packaging (MAP; O₂ 5%, CO₂ 20%, N₂ 75%) and stored at 4 ˚C for 28 days. The data showed that lipid oxidation and spoilage of the samples were significantly delayed in the samples treated with Caper extract associated with MAP (p<0.05). The acceptability limit (7 log CFU g^-1) of the psychrophilic bacterial counts was observed for MAP+Caper (0.5%) treatment in 7 and 14 days of storage time while it was reported for other treatments only in day 7. The use of 0.5 % Caper+MAP had the best antioxidative and antimicrobial effects, as well as sensory scores in the trout fillets during refrigerated storage (28 days) (p<0.05). This study determined that the Caper associated with MAP had significant effects on shelf-life extension of fresh rainbow trout at cold storage period and could be a natural preservative for extending shelf life of fish fillets.

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The present study was conducted to evaluate the effects of nanochitosan with sodium acetate and none-sodium acetate coating on Pseudomonas fluorescens and the shelf life of refrigerated rainbow trout (Onchorhynchus mykiss). 45 samples of rainbow trout filet in five positive and negative treatments including a control, 1% NCH(T2), 2% NCH(T3), 1% NCH+5% NaOAC1 (V/V, T4), 2%NCH2%+ 5%NaOAC1(V/V,T5), the negative groups  incubated by P. fluorescens bacteria (PF+NCH (1 and 2%) +5% NaOACl (V/V) (PF+NCH(1 and 2%)) and a negative control during the 16 days. Comparisons of microbial, chemical and sensory analyses were purely done on safe treatments periodically using one way ANOVA and Duncan tests. Results detected significant differences between the control group and both NCH+5% NaOAC1 (V/V), and NCH free of 5% NaOAC1 (V/V) in all amounts of microbial and chemical indices (p<0.05) and there were no significant differences between the two NCH groups (p>0.05). Sensory indices illustrated that filets treated with each groups of NCH±5% NaOAC1(V/V) received good points and their shelf life was 16 days, but control group settled in this status on sixth day of the test. For the two other treatments, shelf life storage increased and remained on 12 th and 16 th day, respectively. Furthermore, third day of the test showed high amounts of bacteria in the PF incubation treatment.  High levels of bacteria same as that in the control group were determined on sixth day in desirable samples and in NCH+ P. fluorescens, while there was an obvious bacterial reduction in bacterium mixed with NCH+NaOAC and kept for 12 days. Overall, utility of NCH+NaOAC increased the shelf life in refrigerator storage and decreased the amount of P. fluorescens in it.

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One of the subjects attracted the interest of researchers in recent years in the field of biology is marine algae, due to their nutritional value, their benefits for health and their biological activities. In this study, steroid fractions of acetone extract of Colpomenia sinuosa (Phaeophyceae alga) from the Persian Gulf and Oman sea (Iran) have studied and evaluated for their antibacterial activity against pathogenic bacteria: one gram-positive bacterium (Staphylococcus aureus) and two gram-negative bacteria (Escherichia coli, Pseudomonas aeroginosa). Antimicrobial susceptibility tests have expressed in terms of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) of the test organisms with respect to the acetone extracts of Colpomenia sinuosa. Extracts of all tested marine algae have showed inhibition against all of the pathogenic microbes. In addition, the highest inhibition activity among all the extracts was shown from Cholestane fraction to S.aoreus and lower inhibition activity was shown from Oleic acid fraction to P. aeruginosa.

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This study was carried out to evaluate the feasibility of chitosan, a natural antimicrobial substance to improve the caviar shelf life. The effect of chitosan coating was carefully studied within 150 days storage time at -3°C in a standard situation. Both the caviar wrapped  by chitosan and the control sample, were packed in commercial glass Jars. Chemical, microbiological and sensory analyses were done during storage time. Results showed that the effect of chitosan coating on caviar samples was to maintain their good quality characteristics and extend the shelf life of caviar significantly (p<0.05) about 60 days in contrast with standard sample.

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Regarding to the roles of prebiotics and probiotics in feeding the aquatic animals, the aim of this study was to evaluate the effects of Pediococcus acidilactici, Mannan-oligosaccharide prebiotic and Beta-glucan on hematologic and immunologic parameters of the trout. 720 healthy rainbow trout were divided into four groups as the control group and groups treating with prebiotics, probiotics and both. After the treatment, immunologic, hematologic, growth-nutritional parameters were measured with various stressors indicating the positive effects of simultaneous probiotic and prebiotic treatment on all above-mentioned parameters and stress prevention in the trout.