مریم میر بخش

The positive performance of beneficial bacteria (probiotics) in promoting aquatic production has been proven, and Bacillaceae family is considered to be one of the most widely used bacteria in aquaculture. This study was conducted to investigate and compare the effect of indigenous probiotic Bacillus vallismortis IS03 (JQ085958.1) at 1011 CFU kg-1 concentration, on the growth performance, feed efficiency, and the amount of harvested biomass of western white shrimp in earthen culture ponds. Two treatments were considered for this purpose addition of the probiotic to water, addition of the probiotic to feed, and a control group (without the probiotic).  The lowest feed conversion ratio was recorded in the water treatment (1.60) and then, in the feed treatment (1.62), which were significantly different from the control group (1.74) during the 100 days of the culture period in ponds with a stocking density of 500,000 per hectare (p<0.05). The percentage of survival in the water treatment (80.72%) and in the feed treatment (80.09%) was recorded, and there was a significant difference between the water treatment and control group (p<0.05). The highest amount of harvested biomass was in the water treatment and then the feed treatment, respectively, and a significant difference was observed with the control (p<0.05). There was no significant difference between the relative and specific growth rates in the treatments and the control (p<0.05). However, the final weight of shrimp at harvest was significantly different in the water treatment compared to the control treatment (p<0.05). Considering the positive and significant effects of the probiotic B. vallismortis IS03 in the method of adding to water on the survival rate, harvested biomass, and feed conversion ratio, this bacterium can be suggested as a suitable probiotic to be added to the water of shrimp rearing ponds.

This study was aimed to compare the halo diameter (mm) caused by the lack of bacteria growth (Vibrio harvey) in the post-larvae of Vannamei shrimp (Litopenaeus vannamei) under the influence of methanolic, acetone, and aqueous extracts (ppm) of razor clam (Solen vagina). Based on the obtained results, the methanolic extract stopped the growth of Vibrio harvey bacteria at 450 ppm. Although the use of this extract stopped the growth of bacteria at a concentration of 450 ppm, the diameter of the created halo was smaller compared to the halo of non-growth caused by antibiotics. Acetone extract prevented the growth of Vibrio harvey bacteria at 250 ppm and higher concentrations and created a lack of growth halo with a diameter of 2.8 cm. Also, the aqueous extract did not have any inhibitory effect. The results of the mean comparison test showed that there was a significant difference between different concentrations of methanolic and acetone extracts (P<0/05). Also, significant differences were observed between the same effective concentrations of different treatments (250, 300, 350, 400 and 450 ppm) (P<0/05). Therefore, methanolic and acetone extracts of S. vagina can be used as a bioactive substance to prevent vibriosis in Litopenaeus vannamei. However, more studies are suggested to investigate other extracts of this species and their effects.

Similar to mammals, neurohormones regulate reproductive process in fish. Gonadotropin-releasing hormone (GnRH) is one of the most important factors controlling reproduction, which causes gametogenesis by regulating the amount and time of LH and FSH secretion. The highest amount of GnRH isoforms in vertebrates is related to teleost. According to the phylogeny tree, GnRH is classified into three forms (GnRH1, GnRH2, GnRH3) and all fishes have at least two forms. In fish that lack GnRH1, GnRH3 plays an alternative role. Unlike mammals, it seems that GnRH is not the main gate of reproduction, at least in ornamental fish (zebrafish and medaka). However, farming fishes in closed environments such as farms leads to a decrease in the level of GnRH and LH, which causes reproductive impairment. Therefore, the synthesis of GnRH analogs that have prolonged stability is important for the aquaculture industry. Over the last decade molecular techniques have been well developed and the role of other neuropeptides on the production of LH hormone have confirmed which raised new challenges of the relationship between novel peptides and GnRH. The present study is centered on the most important applied and fundamental findings on GnRH.

In the present study, the effects of different probiotics mixtures on growth performance, hematology and antioxidant capacity of Asian seabass (Lates calcarifer) juveniles (30 g). In this study, three bacterial mixtures were used that were isolated from the native aquatic species of Khuzestan and the South of the country, which include: the first group includes different strains of Lactobacillus plantarum, the second group includes L. plantarum with a mixture of L. bulgaricus, L. acidophilus and L. rahamnosus and the third group includes the mixture of bacteria of the first and second groups along with the mixture of Bacillus cereus and B. thuringiensis, which were identified through their quorum quenching features and isolated from Asian sea bass. Four treatments were designed by spraying various bacterial mixture on a basal diet, which included diet (1, control group) on which only sterile physiological serum was sprayed on the diet, diet (2) on which the bacterial mixture of the first group was sprayed on the diet, diet (3) on which the mixture of bacteria of the second group was sprayed and diet (4) which was the mixture of all bacteria was sprayed on it and fed to the fish. The fish was fed with the experimental diets four times a day up to satiation at 30.5 °C for 100 days. In this study, the fish that was fed with 2, 3 and 4 diets had a higher growth performance than the control (p < 0.05), which was associated with an improvement in the food conversion ratio. Blood and antioxidant indices were improved in the fish fed with diets containing probiotics mixture. Treatment 4 had more total plasma protein and albumin than other treatments. In conclusion, the use of a mixture of different probiotics increased growth in Asian seabass that associated with improved health indices in this species.

The aim of this study was to investigate the effects of Estonian and aqueous extracts of Persian walnut leaves on the performance of growth indices in western white shrimp (Litopenaeus vannamei). Materials and methods included 6 treatments of shrimp with different concentrations of 100, 200 and 300 mg/kg aqueous and Estonian extracts of Persian walnut leaves in the diet and 2 negative control treatments and 2 positive control treatments were randomly tested over a period of 40 days. They got Biometrics of stored shrimp were measured for the performance of growth indices.The results showed that the addition of extracts significantly increased protein efficiency in the treatment groups compared to the positive control group (p≥0.05). Addition of aqueous and Estonian extracts of Persian walnut leaves to the diet showed that the extracts had a positive effect on food conversion index on days 20 and 40 of the study (p≥0.05); And this effect is more in Estonian extract than aqueous extract (p ≥ 0.05). The results showed that in the two indices of weight and length in aqueous and Estonian extracts compared to the control groups showed a significant increase (p ≥ 0.05) but no significant difference was observed in the carapace length index among all treatments (p ≥). In the survival index, studies show that at the end of day 11, aqueous and Estonian extracts of 100 mg / kg had a significant positive control compared to the other groups, which shows that these extracts caused more survival of shrimp (p≥0.05).

Microbial infections outbreak in aquatics are important challenges, and farmers have major difficulties dealing with microbes especially regarding their antibiotic resistance. The purpose of this study was comparative evaluating of antimicrobial activity of silver nanoparticles (Ag NPs) against one gram-positive bacteria (Bacillus spp) and a gram-negative (Vibrio harveyi). In this experimental study, the antibacterial effects of Ag NPs was determined by agar well diffusion method through the measurement of the inhibitory zone diameter and micro-broth dilution for determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). According to the results of well diffusion test in agar, the maximum diameter of inhibition zone (44.6 ± 0.15 mm) was related to Bacillus spp. MIC of Ag NPs against Bacillus spp and Vibrio harveyi  were 1.95 and 3.91 mg/ml respectively and MBC was recorded 3.91 mg/ml for both bacteria. Also the kinetic study confirmed the results, So that growth of Bacillus spp 5 hours and V. harveyi 6 hours after exposure to silver nanoparticles was stopped.This study showed that colloidal Ag NPs have higher bactericidal effects on gram-positive bacteria compared with gram-negative bacteria and of course can be a candidate for the elimination of both gram negative and gram positive bacteria, especially in control of infective aquatic microorganisms.

One of the important factors in the use of natural pigments in various foods is their stability and preservation of their antioxidant properties under the production and storage conditions. Astaxanthin is one of these natural pigments that microalgae are one of its resources. In the present study, after the extraction of astaxanthin from hematococcus microalgae (Haematococcus pluvialis) by a combined method (HCL-Acetone), the effect of temperature, pH, and time parameters on its stability and antioxidant activity (DPPH free radical scavenging activity and reducing power of ferric) were evaluated. The results showed that the effect of temperature, pH and time factors alone and the interactions between the time and temperature were significant (p<0.05). However, the interactions of pH with time, pH with temperature, and the interaction of three factors together on the concentration and stability of astaxanthin were not significant (p>0.05). According to the findings, the antioxidant activity and pigment stability at 4 °C was more than 20 °C and with increasing the storage time, these properties were decreased. The pH changes did not have much effect on the pigment properties, although the results at pH=5.5 were relatively better than pH=4.5. Among the studied treatments, DPPH free radical scavenging activity as well as the reducing power of the extracted pigment ranged from 45.5-93.11% and absorption of 0.31-0.81 at 700 nm, respectively. This property makes it possible to use this pigment in food products as an antioxidant. However, use of various methods such as coating the pigment for using in heat-treated foods is recommended due to the low stability of the pigment at the higher temperatures.

This study aimed to investigate the effect of extracted chloroform from sea cucumber (Holothuria Parva) on the survival of white leg shrimp (Litopenaeus vannamei) exposed to Vibrio harveyi and to evaluate changes in immune factors during the experimental period. Sea cucumber samples were collected from the tidal zone of Dayyer county in Bushehr province. Shrimps with an average weight of 10±1 g were collected from culture ponds and kept in 33 aquariums containing 100 liters of water with a salinity of 40 ppt. The results showed that the survival rate in treatments 1, 2, and 3 with consumption of the extracted chloroform was 100%. PO had a significant difference in treatments 1, 2, and 3 with negative and positive control groups. POD had a significant difference in treatments 1, 2, and 3 with the positive control group. THC was significantly different in treatments 1 and 2 with the positive control group and treatment 3 with the negative control group. TPP was significantly different in treatment 1 with positive and negative control groups, in treatment 2 with the negative control group, and treatment 3 with negative and positive control groups. SOD was significantly different in treatment 1 with positive and negative control groups, and in treatments 2 and 3 with negative control groups. According to the results, the survival rate and safety factors were higher in shrimp fed with extracted chloroform compared to shrimp fed with commercial food.

Safety, raising awareness, and preventing the occurrence of hazards are necessary in order to continue to improve the quality of laboratory activities, which have been recently considered by scientific, research, and industrial communities. Therefore, the present study was conducted to determine the risk factor, potential hazards, and provide practical programs in the laboratories of the Shrimp Research Institute.

Safety hazards of eight laboratories of the National Shrimp Research Institute were evaluated during the intervention study with the Failure Mode and Effects Analysis technique. To this end, in the first phase, the team of safety experts (HSE: Health and Safety Executive), by preparing and completing safety questionnaire forms, identified the current status of safety indicators and danger points of laboratories, assessed the distance with safety indicators, and managed danger points. Based on risk severity, probability of occurrence, and probability of risk detection, the risk priority number (RPN) was calculated, prioritized, and corrective measures were proposed. In the second phase, after corrective measures, the safety questionnaire was completed again and the level of risk severity, probability of occurrence, probability of detection, risk priority number, risk number, and percentage reduction of risk priority number of the studied laboratories were calculated and analyzed.

Thirty-five hazard points were identified in the laboratories. The range of risk priority numbers ranged from RPN = 12 for the Plankton Laboratory to RPN = 210 for the Marine Microbiology Laboratories and Marine Pollutants. After control measures, the risk number of marine microbiology laboratory was reduced to 180 and marine pollutants to 120 (P <0.05).

The results showed that FMEA technique is appropriate in identifying the risk points, evaluating, and classifying the risks of the Iran Shrimp Research Institute laboratories and provide control strategies to eliminate or reduce the risk rate of research environments.

Inroduction & Objective:

One of the biggest threats facing the aquaculture industry is bacterial infectious diseases and the use of antibiotics. Phage therapy is a reliable alternative to antibiotics to inactivate bacteria as major pathogens in the aquaculture industry. The aim of this study was to screen Vibrio species off the coast of Bushehr province and control this shrimp pathogen using phage.
 

For this study, water was sampled in 1398 from areas close to the coast of Bushehr province. Bacteria that cause Vibriosis were determined using biochemical tests and molecular sequencing. Bacterial selection was performed according to the results of antibiogram profiles of dominant bacteria and pathogens. TCBS was used to determine the phage titer of the culture medium and the plugs were counted 24 hours after incubation at 30 ° C.

5 bacteria (Vibrio alginolyticus strain SeqID, Vibrio xuii strain Z-03Phage, Vibrio alginolyticus SZ / 10 gene, Vibrio rotiferianus strain SRPR-Phage, Vibrio harveyi strain Z05 were isolated from Bushehr wastewater contaminated waters). Vibrio alginolyticus strain SeqID was selected as the dominant bacterial species according to the results of antibiogram profile determination, growth halo diameter and bacterial biochemical test of the studied species. Based on the results of 16srDNA molecular analysis, the isolated strain of the bacterium was 100% similar to Vibrio alginolyticus. Based on the results of the host domain, Vibrio alginolyticus strain Samira Phage was able to form plugs.

The isolated bacteriophage Vibrio alginolyticus strain Samira Phage had a bactericidal effect with a wide range against Vibrio bacteria identified from the shores of Bushehr, which indicates that this bacteriophage can be a good candidate for use in phage therapy Be against viberosis.

The aim of this study was to identify different population broodstocks of Litopenaeus vannamei and effect of inbreeding and cross-inbreeding on genetic characteristics and inbreeding coefficient of offspring in the next generation. According to origin of broodstocks kept in hatcheries of Bushehr province in the first generation, different populations were identified through microsatellite method from Hybrid, High health and Molokai stocks then, in the next generations genetic characteristics of offspring from their inbreeding and cross-inbreeding were examined. The results showed that the amount of genetic diversity in Molokai and High Health stocks (0.46±0.09 and 0.50±0.07) was more than hybrid stock (0.38±0.06). The inbreeding coefficients of Molokai, High Health and hybrid stocks were 0.14, 0.31 and 0.41, respectively. Due to the low genetic distance between the hybrid and Molokai stocks, after mixing them together Molokai and High Health populations were introduced as the first generation broodstock. In the second generation, despite the high genetic diversity in the offspring of Molokai×High Health (0.47±0.12) and High Health×Molokai (0.39±0.08) than the offspring of Molokai×Molokai (0.19±0.04) and High Health× High Health (0.11±0.03), these values were reduced compared to the first generation. The lowest and highest inbreeding coefficients were related to the offspring of Molokai×High Health (0.268 ±0.18) and Molokai× Molokai (0.853±0.145), respectively. According to the results, it can be said that the lack of knowledge about the genetic characteristics of broodstocks and mating between individual relationships (full and half sib) can reduce genetic characteristics and genetic depression due to increased inbreeding coefficients in next generations.

This research was carried in order to study of pathology and changes of some hematology indicators of indigenous and French Rainbow trout fish after following with Aeromonas hydrophila. For this research, treatments were performed in eight treatments and each treatment with three replications (each replicate containing 10 rainbow trout fish with an average weight 16±0.36 g). two treatments as a negative control (including of indigenous and French fish without bacterial injection), Two treatments as a positive control (including of indigenous and French fish with serum physiology injection), two treatments including indigenous fish with 106 and 108 CFU/ml Aeromonas hydrophila bacteria and two treatments including French fish, which were injected with 106 and 108 CFU/ml of Aeromonas hydrophila by intra-peritoneal method. After 20 days, to determine the values of some hemotology parameters including counts of white blood cells (WBC), red blood cells (RBC), hemoglobin, hematocrit, and MCV, MCH and MCHC indices, blood samples were taken from 6 fish of each treatment, and then, in order to study of pathology of the tissues of the kidney, liver and spleen, fishes were fixed in 10% formalin solution. The present study, the results showed that the hematocrit, hemoglobin and counts of red blood cells decreased significantly in the treatments of infected with bacterial infection of Aeromonas hydrophila compared with the control groups, and the number of white blood cells and neutrophils increased significantly. Lesions such as mild degeneration lesions in liver cells and tissue texture and severe cytoplasmic vacuating of liver cells and complications such as degeneration and necrosis of renal tubules and hyperemia, edema and lose of spleen pulmonary defence cells, the most important changes in tissue pathology were in experimental treatments compared to control. The highest survival rate was observed in indigenous Rainbow trout control group without bacterial injection and with serum physiology injection. Due to the greater capability of internal race resistance along with management measures that have been able to increase survival rates, improvement of environmental conditions and elimination of stressors can be effective in reducing Aeromonas lesions.

In this study, “Tak Cell” probiotic, based on eight-year studies (2009- 2016) of the Iranian Fisheries Sciences Research Institute in National Shrimp Research Institute, and produced in collaboration with the “Tak Zhen Zist ®” company, was added to the diet of western white shrimp (Litopenaeus vannamei) weighing more than 6 grams (in three Different quantities 106, 107 and 108 CFU/Kg) and health indicators (including THC, TPP and DHC) were determined at the beginning and the end of the test period. For this purpose, shrimp was randomly selected and kept in 150-liter aquariums (30 Shrimps in each aquarium). The Shrimps were treated in three treatments and each with three replications and negative control (no probiotic and disease agent) and positive control (With probiotic). In each treatment, shrimps were fed with the “Tak Cell” probiotic pellet three times a day for 40 days and the parameters of temperature; salinity and oxygen were recorded during the test. After 40 days, exposure to white spot virus was challenged and daily mortality and survival rate was recorded for 2 weeks. According to Robertson et. al key, shrimp in the phase between two molting selected and hemolymph sampling was Carried out and the health index, including Total Hemocyte Count (THC), Differentiated Hemocyte Count (DHC) and Total Plasma Protein (TPP) were measured and compared with positive and negative control groups. According to the results, concluded that feeding Litopenaeus vannamei with diets containing 107 and 108 CFU/Kg were significantly increase (P≤0.05). The performance of shrimp immune system and health indicators. In addition, the fed of these diets is effective in increasing the survival rate of shrimp exposure to white spot virus in comparison with the control (P<0.05).

In recent years, the use of probiotics has been considered as an ecological preventive approach to aquaculture, because of the perilous consumption of antimicrobials for humans and the environment, the use of alternative methods is increasing. In this study, we compared the efficacy of different methods of preparation of functional food containing native probiotic Takcell® on the growth performance of juvenile western white shrimp. For this purpose, post larvae of shrimps were fed in 8 experimental treatments in two ways: probiotic Supplemented and sprayed diets at doses of 108, 107, and 106 CFU kg-1 and probiotic-free diets for 40 days in tanks. All probiotic fed- diets showed better performance in relative growth rate, specific growth rate, survival rate and feed conversion ratio compared to control groups (p<0.05). The highest activity of growth indices was observed in spray treatment at a dose of 108 CFU kg-1. There was no significant difference with complementary diets (p>0.05). The results of this study showed that functional food containing native probiotic Takcell®, regardless of doses and preparation methods, resulted in improvement of growth and survival indices in western white shrimp, and the dose of 108 and 107 CFU kg-1 had the highest effect.

An excellent alternative for chemical antimicrobial agents to prevent disease in the shrimp aquaculture is the application of effective probiotics. The present study was evaluated the effect of Bacillus vallismortis IS03 as a native probiotic, isolated from digestive tract of Litopenaeus vannamei on pathogenic Vibrio harveyi under in vitro and in vivo circumstances. Co-cultivation of V. harveyi and B. vallismortis showed significantly (P<0.05) decreased the growth of V. harveyi in the treatment groups compared to the control. Cell-free extracts of B. vallismortis IS03 exhibited more appropriate antibacterial effects on replication of V. harveyi. The highest and lowest inhibitory effects were respectively shown in108 and 106 CFU ml-1 of B. vallismortis IS03 cell-free extracts. The probiotic potential of B. vallismortis IS03 was assessed through the groups of control and the experiments 106, 107 and 108 CFU ml-1 salt water once every 3 days from zoea1 process to end point of the study. The probiotic potential of B. vallismortis IS03 was assessed through the groups of control and the experiments 106, 107 and 108 CFU ml-1 salt water once every 3 days from zoea1 process to end point of the study. Shrimp survival was determined after 10 days of challenge with V. harveyi  at 10 5 CFU ml-1 (for the first 5 days) and 10 7 CFU ml-1  (for the second 5 days).The cumulative mortality in the treatment with 108 CFU ml-1 of  B. vallismortis IS03 reached 11.88% compared to 40.63% in the control group. At the end of the trial, total bacterial counts on TSA, total vibrio on TCBS were significantly (P<0.05) lower in the 108 CFU ml-1 treatment group. Bacillus counts on MYP agar in the treatment groups were significantly (P<0.05) higher than the control, also total bacterial counts was lower in the treatment groups, while, no vibrio were grown in the muscle tissues of shrimp treated with probiotics. It is concluded that 108 CFU ml-1 of probiotic, B. vallismortis IS03 has antibacterial efficiency against pathogenic V. harveyi at in vitro and in vivo conditions.

The purpose of this research was possibility evaluation of indirect use of Ag-NPs-coated porous ceramic in water filtration of culture system of shrimp post larvae to control Vibrio harveyi. After confidence of antibacterial activity of Ag-NPs-coated on porous ceramic against mentioned bacteria via in vitro experiments (Zone of inhibition test and Test tub test), porous ceramic filter media used for water treatment. Therefore, the performance of the Ag-NPs-coated on porous ceramics in removing pathogenic bacteria was studied in two phases: in the first phase, V. harveyi (1.5*108 cfu/ml) was inoculated to the water and efficacy of filters of inhibition of bacteria was evaluated via total count of bacteria in the test water; in the second phase, the performance of the Ag-NPs-coated on porous ceramic was tested in the presence of shrimp larvae and efficacy of filters in inhibition of bacteria was evaluated via total count of bacteria, mortality rate, clinical signs, and also hepatopancreas and muscle culture. Based on the results, the highest zone of inhibition obtained in presence of Ag-NPs-coated porous ceramic modified by an aminosilane coupling agent, 3-aminopropyltriethoxysilane (APTES) (The samples were immersed in the silver colloidal solution for 24 h).The results of flow test showed the highest bacteria removal efficiency from water with complete (100%) removal of the targeted pathogen in the flow rate of 1 L/min. In the second phase, the results indicated significant difference in decreasing of water bacteria, shrimp mortality and disease symptoms in treatment containing silver compounds compare to controls.

Integrated culturing of Gracilaria corticata and Litopenaeus vannamei was surveyed under zero water exchange system in a 45- day period. Water temperature, pH and salinity were measured each 3- day. At the end of culturing period, all seaweeds were separately weighted, dried and their protein, fat, carbohydrate, ash, agar percent and jell strength were measured. The maximum SGR of G. corticata (1.23 ± 0.07% day-1) was observed in treatment S1A1 (25 shrimp per m2 and 200g seaweed per m2) but the maximum agar percent (17 ± 0.2 %) and the maximum agar production (11.21±0.21 gm-2(were observed in S1A2. The maximum jell strength was observed in wild seaweed. Contents of protein, ash, fat and carbohydrate ranged 19.54- 21.31, 33.98 – 35.41, 1.94-2 and 41.95- 43.61% respectively. According to the results, G. corticata can be considered as an important source of protein and carbohydrate.