Effects of Multi-strain probiotic on Muscle Antioxidant Parameters and Fillet Shelf Life of Rainbow Trout

Introduction 
Rainbow trout, oncorhynchus mykiss, is an important aquaculture candidate with more than 800000 tons of world annual production (Yousefi et al., 2022a). Aquaculture of rainbow trout is an essential sector of the food supply in Iran (Dezfuly et al., 2019), with more than 170000 tons annual production (Yousefi et al., 2022c). Although aquaculture can supply high-quality human food, fish/shellfish meat is very susceptible to perishing due to their relatively high protein content, nitrogenous compounds, and unsaturated fats in muscles (Arulkumar et al., 2017). Refrigeration is one of the methods that can be used to increase the shelf life of fish meat in fish supply centers or for transferring fish from aquaculture centers to markets. Fish storage in refrigerators reduces the rate of enzymatic, chemical, and microbial activities. However, undesirable changes such as oxidation and hydrolysis of fats slowly deteriorate the quality of the products due to the inability of the fridge to minimize fish meat temperature to the necessary level (Pérez-Alonso et al., 2003). Therefore, using methods to improve the quality and increase the shelf life of meat is essential to prevent economic losses and maintain consumer health. Many studies have been conducted on adding preservatives to fish fillets after harvesting (Hussain et al., 2021). However, improving the antioxidant conditions of fish during rearing may help improve the quality of fish fillets in the refrigerator after harvesting.
Probiotics are widely used in aquaculture and can improve fish growth, immunity, and antioxidant systems (Balcázar et al., 2008; Alishahi et al., 2018). For this reason, the use of probiotics in aquaculture increases economic efficiency. The most comprehensive definition of probiotics was provided by Merrifield et al. (2010): “In general, any microbial cell that enters a living organism’s body through feed or water in aquaculture and creates beneficial effects for the fish and consumer by improving microbial balance is called a probiotic.” Probiotics can create an unfavorable environment for pathogens and control them by various mechanisms such as the production and secretion of inhibitory compounds, competition with pathogenic agents, opportunistic consumption of essential nutrients and attachment sites in the digestive system, as well as stimulating the host’s immune system (Balcázar et al., 2008; Wang et al., 2010). Studies have shown that probiotics can improve growth performance, feed utilization, and digestibility of dietary components in fish (Rohani et al., 2021).
Adding probiotics to the fish diet can increase the antioxidant power of fish, as the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase in various fish tissues increases and the amount of thiobarbituric reactive substances (TBARS) decreases (Tovar-Ramírez et al., 2010; Duan et al., 2017; Gobi et al., 2018). However, few studies have focused on the antioxidant effects of probiotics on muscle antioxidant indices and fillet quality during refrigerated condition. For example, the use of the yeast probiotic Rhodosporidium paludigenum in the diet of white leg shrimp, Penaeus vannamei, led to an increase in the activity of muscle antioxidant enzymes and a decrease in TBARS levels (Yang et al., 2010). Adding the probiotic Bacillus vireti to the freshwater prawn Macrobrachium rosenbergii diet improves muscle’s antioxidant status after disease occurrence in animals (Vidhya Hindu et al., 2018). Dietary supplementation with Bacillus subtilis improves intestinal antioxidant indices and increases physical quality indices of the muscle in crucian carp, Carassius auratus (Cao et al., 2019). Adding a probiotic mixture of Bacillus subtilis, Enterococcus faecium, Pediococcus acidilactici, and Lactobacillus reuteri to rainbow trout diets increases antioxidant enzyme activity. It decreases TBARS levels in the fish fillet after 5 days of refrigerated condition (Giannenas et al., 2015). Therefore, adding probiotics to fish diets can improve fish’s growth and disease resistance and increase fillet quality and shelf life in refrigerated condition, which is important for consumer health. However, further research is needed due to limited studies in this area and the variety of probiotics and fish species (with different muscle compositions) on the market. 
In the present study, a commercial probiotic consortium (Bio-Aqua, Biodep Co., Tehran, Iran) composed of 9 bacterial and yeast strains (P. acidilactici, E. faecium, B. subtilis, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus casei, Lactobacillus rhamnosus, Bifidobacterium bifidum, and Saccharomyces cerevisiae) was used for dietary supplementation and administration to rainbow trout. This product has been formulated explicitly for fish and has a 3×109 CFU/g cell density. The recommended dose of this product is 0.2-0.3 g/kg, although studies have shown that adding 1-2 g/kg of this product to the diet can increase the growth rate of male and female breeders (Akbari Nargesi et al., 2018; Akbari Nargesi et al., 2019). However, no data shows its benefits on rainbow trout fillet quality in refrigerator. Therefore, the study aims to investigate the effect of adding Bio-Aqua probiotics to rainbow trout diets on antioxidant indices and biochemical quality of fish fillets during refrigerated conditions.

Materials and Methods

Fish diets
This study used a specific rainbow trout feed (Faradaneh Co., Tehran, Iran). Bio-Aqua was a gift from Zist Darman Mahan Co. (Tehran, Iran). To prepare the diets, the probiotic supplement was first mixed with water and then sprayed onto the surface of the pellets. The concentrations used in this study were 0 (control=CTR), 0.3, 1, and 2 g/kg of feed. The amount of 0.3 g/kg was selected based on the manufacturer’s recommendation, and the amounts of 1 and 2 g/kg were based on previous studies on rainbow trout (Akbari Nargesi et al., 2018; Akbari Nargesi et al., 2019). After spraying the probiotic onto the feed surface, a gelatin solution was sprayed to prevent the probiotic from being washed away. The feed pellets were used for fish feeding after drying.

Fish culture
In this study, rainbow trout with a mean weight of ~50 g were purchased from a local farm (Aliabad, Golestan Province, Iran). The fish were allowed to acclimatize to the new conditions for 10 days, during which they were fed the control diet and kept in a 2000 L tank with aeration and water flow rate of 5 L/min. Then, 240 fish (61.02±0.13 g) were distributed among twelve 300 L tanks. Each of the three tanks was considered one dietary treatment, and fish were fed daily with the mentioned diets at a rate of 3% biomass (Yousefi et al., 2023a). The rearing tanks were equipped with aeration and constant water flow. Every two weeks, the biomass of each tank was measured to adjust the daily feed amount accordingly. After 12 weeks of culture, the final weight of the fish was recorded, and growth and feed efficiency were calculated based on the Equation 1 (Mirghaed et al., 2023): 

The proximate composition and antioxidant indices of fish muscle
At the end of the culture period, three muscle samples were taken from each treatment. For this purpose, a piece of dorsal muscle was cut and immediately frozen in liquid nitrogen (Ahmadifar et al., 2023). These samples were used to investigate the biochemical composition and antioxidant parameters, including the activity of SOD, CAT, and GPx, as well as the amount of TBARS. The biochemical composition of the muscle, including moisture, fat, protein, and ash, was determined according to the Association of Official Analytical Chemists (AOAC) (AOAC, 2023) method. Moisture was measured using an oven at 105°C for 24 h. Fat was measured using ether extraction and a soxhlet apparatus. Protein was determined using the Kjeldahl method by measuring the nitrogen content of the samples. Ash was determined using an electric furnace at 550 °C for 8 h (AOAC, 2023). 
The samples were first homogenized in phosphate buffer (pH=7.4) to determine the antioxidant parameters and centrifuged at 4°C (15 min and 13000×g). Then, the upper part of the sample was separated and used to measure the mentioned parameters. The activity of SOD was calculated based on the rate of cytochrome C reduction using a commercial kit from ZellBio Co. (Germany) (Hoseini et al., 2020). CAT activity was measured based on the rate of hydrogen peroxide decomposition. Hydrogen peroxide was used as a substrate, and ammonium molybdate was used as a chromogen and reaction stopper (Goth, 1991). GPx activity was measured based on the rate of glutathione oxidation using a commercial kit from ZellBio Co. (Germany) (Hoseini et al., 2019). TBARS was estimated based on the reaction with thiobarbituric acid at a temperature of 95°C using Oakes et al. (2003) method. In this method, the samples were first deproteinized with trichloroacetic acid. Then, the samples were incubated with a thiobarbituric acid solution in the presence of butylated hydroxytoluene (BHT) for 2 h at a temperature of 95°C to produce a red color. The absorbance of the samples was recorded at a wavelength of 534 nm, and the amount of TBARS was calculated based on the Equation 2:
2. TBARS=Sample absorbance-Blank absorbanc/1560000

Investigation of fillet quality indices during refrigerated storage
Three fillets from each treatment were used to investigate the fillet quality indices. For this purpose, the fillets were placed in a refrigerator, and the total bacterial count, psychrotrophic bacterial count, TVBN and TBARS will be determined on days 0, 4, 8, 12 and 16.
The samples were first homogenized in a 0.85% sodium chloride solution to determine the total bacterial and psychrotrophic bacteria counts. Then, different dilutions of these solutions were prepared and cultured on a nutrient agar medium. The total bacterial count was determined after 48 h of incubation at 37°C, and the psychrotrophic bacteria count was determined after 7 days of incubation at a temperature of 10°C (Ojagh et al., 2010).
The total volatile base nitrogen (TVBN) was determined using Goulas & Kontominas’s (2005) method. In this method, magnesium oxide was used to homogenize the samples. Then, the distillation process was performed on the homogenized samples, and the volatile bases were collected in a flask containing boric acid and an indicator. The amount of volatile bases is calculated after titration with sulfuric acid.

Statistical analysis
Normal distribution and homoscedasticity of the data were confirmed by the Shapiro-Wilk and Levene’s tests, respectively. Data of growth performance, feed efficiency, survival, muscle antioxidant enzymes’ activities, and proximate composition were subjected to one-way ANOVA and Duncan tests. Repeated measure ANOVA and Duncan test analyzed fillet quality parameters during the refrigerated condition. All analyses were performed in SPSS software, version 22 and expressed as Mean±SE. 

Results
Growth performance, feed efficiency, and survival of fish within different treatments are presented in Table 1. The treatments had no significant differences in growth performance and feed efficiency. No mortality was observed in various treatments 

Proximate composition analysis showed that dietary probiotics did not significantly affect the fish muscle moisture, fat, and ash percentages (Figure 1). On the other hand, the muscle protein percentage increased dramatically in 0.3B, compared to CTR treatment groups. 

There was a significant elevation in SOD activity in 0.3B compared to the other treatments (Figure 2). The muscle CAT and GPx activities significantly increased in 0.3B and 1B treatments, compared to CTR and 2B treatments (Figure 2). 

Fillet total bacterial count and psychrotrophic bacterial count increased over time during refrigerated condition (Table 2; Figure 3).

An interaction effect of dietary probiotics and sampling time was observed in total bacterial count. The probiotic treatments exhibited significantly lower total bacterial count than CTR after 8 and 16 days. The lowest total bacterial counts were observed in 1B and 0.3B treatments after 8 and 16 days, respectively (Figure 3).

Fillet TBARS and TVBN exhibited elevation over time during refrigerated condition (Table 2; Figure 4). Dietary probiotics significantly affected the fillet TBARS concentrations, as 0.3B and 1B showed lower TBARS than CTR and 2B treatments (Figure 3). There were no interaction effects of dietary probiotics and sampling time on the fillet TVBN and TBARS (Figure 4).

Discussion
Probiotics are used to increase fish growth performance and well-being (Merrifield & Carnevali, 2014; Soltani et al., 2023). However, the growth-promoting effects of probiotics are context-dependent. The present results do not align with Akbari Nargesi et al. (2019) and Akbari Nargesi et al., (2018), who reported growth increase in male and female rainbow trout at 1 and 2 g/kg, respectively. Although several studies have reported enhancement in the growth rate of fish-fed probiotics (El-Haroun et al., 2006; Giannenas et al., 2015; Ramos et al., 2015; Standen et al., 2016), the present results are similar to Shakourian et al. (2021), Nasiripour et al. (2018) and Merrifield et al. (2010) who found no growth enhancement in Siberian sturgeon, Acipenser baerii, and rainbow trout, as a result of dietary supplementation with probiotic consortium. Probiotic effects on fish growth are time-dependent. Many studies have shown that a probiotic/probiotic consortium can cause growth-promoting effects over a long time compared to a short time. In the present study, 0.3B treatment exhibited non-significant improvement in fish growth and feed efficiency. Therefore, Bio-Aqua at 0.3 g/kg may increase rainbow trout’s growth and feed efficiency over a longer time. 
An increase in muscle protein content can be related to various factors. Probiotics have been demonstrated to decrease stress in fish (Gomes et al., 2009), so they may suppress stress-mediated muscle proteolysis, as proposed by Sadoul & Vijayan (2016). On the other hand, probiotics may act against myostatin, a protein that blocks muscle growth (Michelato et al., 2017), as observed in European sea bass, Dicentrarchus labrax, administered by dietary Lactobacillus delbrueckii (Carnevali et al., 2006). The present results are in line with those obtained in mrigal carp, Cirrhinus mrigala (Ullah et al., 2018), largemouth seabass, Micropterus salmoides (Wang et al., 2021), and Asian seabass, Lates calcarifer (Lin et al., 2017), after dietary administration of probiotic consortiums. 
Reactive oxygen species are common products of cell metabolism and are neutralized by antioxidant enzymes (Yousefi et al., 2022b; Yousefi et al., 2023b). Fish rely on their antioxidant system, which includes enzymes such as SOD, CAT, and GPx (Abbasi et al., 2023; Koohkan et al., 2023). However, if the antioxidant system is overwhelmed, biological materials can be oxidized. Unsaturated fatty acids are particularly vulnerable to oxidation and can lead to the formation of TBARS, which are toxic and can cause further damage to biological materials (Rajabiesterabadi et al., 2020; Hoseini et al., 2022). Probiotics can increase the antioxidant capacity of fish (Hoseinifar et al., 2021), and present results suggest Bio-Aqua improves the activity of SOD, CAT, and GPx in the muscle of rainbow trout. Similar results were obtained by other researchers when rainbow trout (Giannenas et al., 2015), white leg shrimp (Yang et al., 2010), and freshwater prawn (Vidhya Hindu et al., 2018) were treated with dietary probiotics. 
Dietary Bio-Aqua supplementation (0.3B and 1B) decreased TBARS content during the refrigerated condition, which aligns with a previous study on rainbow trout (Giannenas et al., 2015). Such benefits can be related to the higher concentration of antioxidants and lower concentration of pro-oxidant compounds in these treatments that protect lipid peroxidation during refrigerated condition when the cellular antioxidant system does not work. Supporting this hypothesis, it has been found that probiotic administration increases the reducing capacity of different fish/shellfish organs (Xie et al., 2019; Chen et al., 2020). 
Microbial spoilage is a significant cause of food loss worldwide, accounting for a remarkable portion of annual production losses (Mirsadeghi et al., 2023). Due to microbial activity, fresh and lightly preserved seafood are particularly susceptible to spoilage (Li et al., 2013). To address this issue, monitoring microbial loads in fish fillets during refrigerated condition is inevitable. There is a gradual increase in total bacterial count, psychrotrophic bacterial count, and TVBN over the refrigerated condition period, which is expected (Li et al., 2013; Nowzari et al., 2013; Ramezani et al., 2015). Interestingly, 0.3 and 1 g/kg dietary probiotics decreased total bacterial count after 8 and 16 days of refrigeration storage, indicating the role of Bio-Aqua in decreasing microbial count during refrigeration condition. There is no similar study for comparison, but feeding chicken with diets containing S. cerevisiae decreased bacterial load while kept in the refrigerator (Aksu et al., 2005). Applying probiotics in packing fish fillets also showed similar effects (Yasin et al., 2020). On the other hand, probiotics can produce antibacterial compounds with antagonistic effects against harmful microbes (Hamad et al., 2022).

Conclusion 
In conclusion, dietary supplementation with Bio-Aqua has no significant effects on the growth performance of rainbow trout. However, 0.3 or 1 g/kg of this probiotic increases muscle protein content and activity of antioxidant enzymes. These concentrations also decrease lipid peroxidation during refrigerated condition storage. 

Ethical Considerations

Compliance with ethical guidelines
This study was conducted in accordance of Ethical Guidelines for the Use of Laboratory Animals in Scientific Research" of the University of Tehran, Tehran, Iran.

Funding
The paper was extracted from the PhD dissertation of Faramarz Amiri, approved by the Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.

Authors' contributions
Conceptualization, supervision and data analysis: Afshin Akhondzadeh Basti, Ali Taheri Mirghaed, Negin Noori, and Parastoo Pourashoori; Methodology: Faramarz Amiri; Data collection: Faramarz Amiri; Investigation: Faramarz Amiri; Writing: All authors. 

Conflict of interest
The authors declared no conflict of interest for this article.

Acknowledgments
The authors thanks the staffs of the Inland Waters Aquatics Resources Research Center, Gorgan, Iran for their help in fish rearing and sampling.

References

Abbasi, M., Taheri Mirghaed, A., Hoseini, S. M., Rajabiesterabadi, H., Hoseinifar, S. H., & Van Doan, H. (2023). Effects of dietary glycine supplementation on growth performance, immunological, and erythrocyte antioxidant parameters in common carp, Cyprinus carpio. Animals, 13(3), 412. [DOI:10.3390/ani13030412] [PMID]

Ahmadifar, E., Kalhor, N., Yousefi, M., Adineh, H., Moghadam, M. S., & Sheikhzadeh, N., et al. (2022). Effects of dietary Plantago ovata seed extract administration on growth performance and immune function of common carp (Cyprinus carpio) fingerling exposed to ammonia toxicity. Veterinary Research Communications, 47(2), 731–744. [DOI:10.1007/s11259-022-10034-5] [PMID]

Akbari Nargesi, E., Falahatkar, B., & Sajjadi, M. (2018). [The effect of probiotic on growth performance and hematological indices in female rainbow trout (Oncorhynchus mykiss) broodstock (Persian)]. Journal of Aquatic Ecology, 8(2), 51-60. [Link]

Akbari Nargesi, E., Falahatkar, B. and Mohammadi, M. (2019) Growth performance and hematological indices in rainbow trout (Oncorhynchus mykiss): Exclusive study of probiotic effect on male broodstock. Iranian Scientific Fisheries Journal, 28(3), 101-112. [Link]

Aksu, M. I., KaraoGlu, M., EsenbuGa, N., Kaya, M., Macit, M., & Ockerman, H. W. (2005). Effect of a dietary probiotic on some quality characteristics of raw broiler drumsticks and breast meat. Journal of Muscle Foods, 16(4), 306-317. [DOI:10.1111/j.1745-4573.2005.00023.x]

Alishahi, M., Dezfuly, Z. T., Mesbah, M., & Mohammadian, T. (2018). Effects of two probiotics, Lactobacillus plantarum and Lactobacillus bulgaricus on growth performance and intestinal lactic acid bacteria of Cyprinus carpio. Iranian Journal of Veterinary Medicine, 12(3), 207-2017. [Link]

AOAC (2023) Official methods of analysis of the association of official analytical chemists. Washington: Association of Official Analytical Chemists. [link]

Arulkumar, A., Paramasivam, S., Rameshthangam, P., & Rabie, M. A. (2017). Changes on biogenic, volatile amines and microbial quality of the blue swimmer crab (Portunus pelagicus) muscle during storage. Journal of Food science and Technology, 54(8), 2503–2511. [DOI:10.1007/s13197-017-2694-5] [PMID]

Balcázar, J. L., Vendrell, D., de Blas, I., Ruiz-Zarzuela, I., Muzquiz, J. L., & Girones, O. (2008) Characterization of probiotic properties of lactic acid bacteria isolated from intestinal microbiota of fish. Aquaculture (Amsterdam, Netherlands), 278(1-4), 188-191. [DOI:10.1016/j.aquaculture.2008.03.014]

Cao, H., Yu, R., Zhang, Y., Hu, B., Jian, S., Wen, C., ... & Yang, G. (2019). Effects of dietary supplementation with β-glucan and Bacillus subtilis on growth, fillet quality, immune capacity, and antioxidant status of Pengze crucian carp (Carassius auratus var. Pengze). Aquaculture, 508, 106-112. [DOI:10.1016/j.aquaculture.2019.04.064]

Carnevali, O., de Vivo, L., Sulpizio, R., Gioacchini, G., Olivotto, I., & Silvi, S., et al. (2006). Growth improvement by probiotic in European sea bass juveniles (Dicentrarchus labrax, L.), with particular attention to IGF-1, myostatin and cortisol gene expression. Aquaculture (Amsterdam, Netherlands), 258(1-4), 430-438. [DOI:10.1016/j.aquaculture.2006.04.025]

Chen, X., Zhang, Z., Fernandes, M. O., Gao, Y., Yin, P., & Liu, Y., et al. (2020). Beneficial effects on growth, haematic indicators, immune status, antioxidant function and gut health in Juvenile Nile tilapia (Oreochromis niloticus) by dietary administration of a multi-strain probiotic. Aquaculture Nutrition, 26(4), 1369-1382. [DOI:10.1111/anu.13094]

Duan, Y., Zhang, Y., Dong, H., Wang, Y., & Zhang, J. (2017). Effect of the dietary probiotic Clostridium butyricum on growth, intestine antioxidant capacity and resistance to high temperature stress in kuruma shrimp Marsupenaeus japonicus. Journal of Thermal Biology, 66, 93-100. [PMID]

El-Haroun, E. R., Goda, A. M. A. S., & Kabir Chowdhury, M. A. (2006). Effect of dietary probiotic Biogen® supplementation as a growth promoter on growth performance and feed utilization of Nile tilapia Oreochromis niloticus (L.). Aquaculture Research, 37(14), 1473-1480. [DOI:10.1111/j.1365-2109.2006.01584.x]

Giannenas, I., Karamaligas, I., Margaroni, M., Pappas, I., Mayer, E., & Encarnação, P., et al. (2015). Effect of dietary incorporation of a multi-strain probiotic on growth performance and health status in rainbow trout (Oncorhynchus mykiss). Fish Physiology and Biochemistry, 41(1), 119–128. [DOI:10.1007/s10695-014-0010-0] [PMID]

Gobi, N., Vaseeharan, B., Chen, J. C., Rekha, R., Vijayakumar, S., & Anjugam, M., et al. (2018). Dietary supplementation of probiotic Bacillus licheniformis Dahb1 improves growth performance, mucus and serum immune parameters, antioxidant enzyme activity as well as resistance against Aeromonas hydrophila in tilapia Oreochromis mossambicus. Fish & Shellfish Immunology, 74, 501-508. [PMID]

Gomes, L. C., Brinn, R. P., Marcon, J. L., Dantas, L. A., Brandão, F. R., & De Abreu, J. S., et al. (2009). Benefits of using the probiotic Efinol®L during transportation of cardinal tetra, Paracheirodon axelrodi (Schultz), in the Amazon. Aquaculture Research, 40(2), 157-165. [DOI:10.1111/j.1365-212008.02077.x]

Goth, L. (1991) A simple method for determination of serum catalase activity and revision of reference range. Clinica Chimica Acta; International Journal of Clinical Chemistry, 196(2-3), 143–151. [DOI:10.1016/0009-8981(91)90067-M] [PMID]

Goulas, A. E., & Kontominas, M. G. (2005). Effect of salting and smoking-method on the keeping quality of chub mackerel (Scomber japonicus): Biochemical and sensory attributes. Food Chemistry, 93(3), 511-520. [DOI:10.1016/j.foodchem.2004.09.040]

Hamad, G., Ombarak, R.A., Eskander, M., Mehany, T., Anees, F. R., & Elfayoumy, R. A., et al. (2022). Detection and inhibition of Clostridium botulinum in some Egyptian fish products by probiotics cell-free supernatants as bio-preservation agents. LWT, 163, [DOI:10.1016/j.lwt.2022.113603]

Hoseini, S. M., Hoseinifar, S. H., & Van Doan, H. (2020). Growth performance and hematological and antioxidant characteristics of rainbow trout, Oncorhynchus mykiss, fed diets supplemented with Roselle, Hibiscus sabdariffa. Aquaculture (Amsterdam, Netherlands), 530, [DOI:10.1016/j.aquaculture.2020.735827]

Hoseini, S. M., Rajabiesterabadi, H., Khalili, M., Yousefi, M., Hoseinifar, S. H., & Van Doan, H. (2019). Antioxidant and immune responses of common carp (Cyprinus carpio) anesthetized by cineole: Effects of anesthetic concentration. Aquaculture (Amsterdam, Netherlands), 520, [DOI:10.1016/j.aquaculture.2019.734680]

Hoseini, S.M., Yousefi, M., Abbasi, M., Kulikov, E.V., Drukovsky, S.G., & Petrov, A.K., et a (2022) Improvement of growth performance, hepatic and erythrocyte antioxidant capacity, innate immunity, and biochemical parameters of Persian sturgeon, Acipenser persicus, by sulfur amino acids’ supplementation. Aquaculture Nutrition, 2022: 2025855. [DOI: 10.1155/2022/2025855]

Hoseinifar, S. H., Yousefi, S., Van Doan, H., Ashouri, G., Gioacchini, G., & Maradonna, F., et al. (2020). Oxidative stress and antioxidant defense in fish: The implications of probiotic, prebiotic, and synbiotics. Reviews in Fisheries Science & Aquaculture, 29(2), 198-217. [Link]

Hussain, M. A., Sumon, T. A., Mazumder, S. K., Ali, M. M., Jang, W. J., & Abualreesh, M. H., et al. (2021). Essential oils and chitosan as alternatives to chemical preservatives for fish and fisheries products: A review. Food Control, 129, [DOI:10.1016/j.foodcont.2021.108244]

Koohkan, O., Morovvati, H., & Mirghaed, A. T. (2023). Effects of Spirulina platensis on iron oxide nanoparticles induced-oxidative stress and liver damage in grey mullet (Mugil cephalus). Iranian Journal of Veterinary Medicine, 17(1), 75-86.[DOI:10.32598/IJVM.17.1.1005284]

Li, T., Li, J., Hu, W., & Li, X. (2013). Quality enhancement in refrigerated red drum (Sciaenops ocellatus) fillets using chitosan coatings containing natural preservatives. Food Chemistry, 138(2-3), 821–826. [DOI:10.1016/j.foodchem.2012.11.092] [PMID]

Lin, H. L., Shiu, Y. L., Chiu, C. S., Huang, S. L., & Liu, C. H. (2017). Screening probiotic candidates for a mixture of probiotics to enhance the growth performance, immunity, and disease resistance of Asian seabass, Lates calcarifer (Bloch), against Aeromonas hydrophila. Fish & Shellfish Immunology, 60, 474-482. [DOI:10.1016/j.fsi.2016.11.026] [PMID]

Merrifield, D. L., & Carnevali, O. (2014). Probiotic modulation of the gut microbiota of fish. Aquaculture Nutrition: Gut Health, Probiotics and Prebiotics, 185-222. ch8 [DOI: 10.1002/9781118897263.ch8]

Merrifield, D. L., Bradley, G., Baker, R. T. M., & Davies, S. J. (2010). Probiotic applications for rainbow trout (Oncorhynchus mykiss Walbaum) II. Effects on growth performance, feed utilization, intestinal microbiota and related health criteria postantibiotic treatment. Aquaculture Nutrition, 16(2), 496-503. [DOI:10.1111/j.1365-2095.2009.00688.x]

Michelato, M., Zaminhan, M., Boscolo, W. R., Nogaroto, V., Vicari, M., & Artoni, R. F., et al. (2017). Dietary histidine requirement of Nile tilapia juveniles based on growth performance, expression of muscle-growth-related genes and haematological responses. Aquaculture (Amsterdam, Netherlands), 467, 63-70. [DOI:10.1016/j.aquaculture.2016.06.038]

Mirghaed, A.T., Mirzargar, S. S., Ghelichpour, M., Moghaddam, A. A., El-Haroun, E., & Hoseini, S. M. (2023). Effects of dietary lactic acid supplementation on growth performance, hemato-immunological parameters, and calcium and phosphorus status of common carp, Cyprinus ca Aquaculture Reports, 29, 101499. [DOI:10.1016/j.aqrep.2023.101499]

Mirsadeghi, H., Alishahi, A., Shabanpour, B., Safari, R., & Daneshvar, M. (2023). Effects of salting and refrigerator storage on rainbow trout (Oncorhynchus mykiss) roe quality: Chemical and microbial changes. Iranian Journal of Veterinary Medicine, 17(1), 87-98. [DOI:10.32598/IJVM.17.1.1005059]

Nasiripour, S., Jafaryan, H., Gholipour, K. H., & Harsij, M. (2018). [The effect of commercial Multi-Behsil probiotic on growth performance, feeding efficiency and carcass quality of rainbow trout (Oncorhynchus mykiss) juvenile (Persian)]. Journal of Aquaculture Sciences, 6, 42-52. [Link]

Nowzari, F., Shábanpour, B., & Ojagh, S. M. (2013). Comparison of chitosan-gelatin composite and bilayer coating and film effect on the quality of refrigerated rainbow trout. Food Chemistry, 141(3), 1667–1672. [PMID]

Oakes, K. D., & Van Der Kraak, G. J. (2003). Utility of the TBARS assay in detecting oxidative stress in white sucker (Catostomus commersoni) populations exposed to pulp mill effluent. Aquatic Toxicology, 63(4), 447-463. [DOI:10.1016/s0166-445x(02)00204-7] [PMID]

Ojagh, S. M., Rezaei, M., Razavi, S. H., & Hosseini, S. M. H. (2010). Effect of chitosan coatings enriched with cinnamon oil on the quality of refrigerated rainbow trout. Food Chemistry, 120(1), 193-198. [DOI:10.1016/j.foodchem.2009.10.006]

Pérez-Alonso, F., Arias, C., & Aubourg, S.P. (2003). Lipid deterioration during chilled storage of Atlantic pomfret (Brama brama). European Journal of Lipid Science and Technology, 105(11), 661-667. [DOI:10.1002/ejlt.200300804]

Rajabiesterabadi, H., Hoseini, S. M., Fazelan, Z., Hoseinifar, S. H., & Doan, H. V. (2020). Effects of dietary turmeric administration on stress, immune, antioxidant and inflammatory responses of common carp (Cyprinus carpio) during copper exposure. Aquaculture Nutrition, 26(4), 1143-1153. [DOI:10.1111/anu.13071]

Ramezani, Z., Zarei, M., & Raminnejad, N. (2015). Comparing the effectiveness of chitosan and nanochitosan coatings on the quality of refrigerated silver carp fillets. Food Control, 51, 43-48. [DOI:10.1016/j.foodcont.2014.11.015]

Ramos, M. A., Gonçalves, J. F., Batista, S., Costas, , Pires, M. A., & Rema, P., et al. (2015). Growth, immune responses and intestinal morphology of rainbow trout (Oncorhynchus mykiss) supplemented with commercial probiotics. Fish & Shellfish Immunology, 45(1), 19–26. [PMID]

Rohani, M. F., Islam, S. M., Hossain, M. K., Ferdous, Z., Siddik, M. A., & Nuruzzaman, M., et al. (2022). Probiotics, prebiotics and synbiotics improved the functionality of aquafeed: Upgrading growth, reproduction, immunity and disease resistance in fish. Fish & Shellfish Immunology, 120, 569–589. [DOI:10.1016/j.fsi.2021.12.037] [PMID]

Sadoul, B., & Vijayan, M. M. (2016). 5 - stress and growth. In: Schreck C.B., Tort L., Farrell A.P. & Brauner C.J. (Eds), Fish physiology. pp. 167-205. Academic Press: Academic Press. [DOI: 10.1016/B978-0-12-802728-8.00005-9]

Shakourian, M., Alipour, J. A. R., Bagherzadeh, L. F., Yazdani, S. M. A., Hosseinpour, Z. A., & Seyed, H. S. H. (2021). [The effects of different levels of native commercial probiotic (Super zist) on the growth, nutritional efficiency and survival rate of Siberian sturgeon (Acipenser baerii) Juvenile (Persian)]. Journal of Aquaculture Development, 14(4), 55-67. [Link]

Soltani, M., Shafiei, S., Mirzargar, S. S., & Asadi, S. (2023). Probiotic, paraprobiotic and postbiotic as an alternative to antibiotic therapy towards Lactococcosis in aquaculture. Iranian Journal of Veterinary Medicine, 17(4), 287-300. [DOI:10.32598/IJVM.17.4.1005342]

Standen, B. T., Peggs, D. L., Rawling, M. D., Foey, A., Davies, S. J., & Santos, G. A., et al. (2016). Dietary administration of a commercial mixed-species probiotic improves growth performance and modulates the intestinal immunity of tilapia, Oreochromis niloticus. Fish & Shellfish Immunology, 49, 427-435. [DOI:10.1016/j.fsi.2015.11.037] [PMID]

Tovar-Ramírez, D., Mazurais, D., Gatesoupe, J., Quazuguel, P., Cahu, C., & Zambonino-Infante, J. (2010). Dietary probiotic live yeast modulates antioxidant enzyme activities and gene expression of sea bass (Dicentrarchus labrax) larva Aquaculture (Amsterdam, Netherlands), 300(1-4), 142-147. [DOI:10.1016/j.aquaculture.2009.12.015]

Dezfuly, Z. T., Alishahi, M., Ghorbanpoor, M., Tabandeh, M. R., & Mesbah, M. (2019). Effects of lipopolysaccharides (LPS) of Yersinia ruckeri on immune response in rainbow trout (Oncorhynchus mykiss) by intraperitoneal and oral administration. Iranian Journal of Veterinary Medicine, 13(4), 421-435. [Link]

Ullah, A., Zuberi, A., Ahmad, M., Bashir Shah, A., Younus, N., & Ullah, S., et al. (2018). Dietary administration of the commercially available probiotics enhanced the survival, growth, and innate immune responses in Mori (Cirrhinus mrigala) in a natural earthen polyculture system. Fish & Shellfish Immunology, 72, 266–272. [DOI:10.1016/j.fsi.2017.10.056] [PMID]

Vidhya Hindu, S., Chandrasekaran, N., Mukherjee, A., & Thomas, J. (2018). Effect of dietary supplementation of novel probiotic bacteria Bacillus vireti 01 on antioxidant defence system of freshwater prawn challenged with Pseudomonas aeruginosa. Probiotics and Antimicrobial Proteins, 10(2), 356–366.[DOI:10.1007/s12602-017-9317-3] [PMID]

Wang, J., Zhu, Z., Tian, S., Fu, H., Leng, X., & Chen, L. (2021).Dietary Lactobacillus casei K17 Improves lipid metabolism, antioxidant response, and fillet quality of Micropterus salmoides. Animals, 11(9), 2564. [DOI:10.3390/ani11092564] [PMID]

Wang, W., Zhou, Z., He, S., Liu, Y., Cao, Y., & Shi, P., et al. (2010). Identification of the adherent microbiota on the gills and skin of poly-cultured gibel carp (Carassius auratus gibelio) and bluntnose black bream (Megalobrama amblycephala Yih). Aquaculture Research, 41(9), e72-e83. [DOI:10.1111/j.1365-2109.2009.02459.x]

Xie, J. J., Liu, Q. Q., Liao, S., Fang, H. H., Yin, P., & Xie, S. W., et al. (2019). Effects of dietary mixed probiotics on growth, non-specific immunity, intestinal morphology and microbiota of juvenile pacific white shrimp, Litopenaeus vannamei. Fish & Shellfish Immunology, 90, 456-465. [PMID]

Yang, -P., Wu, Z.-H., Jian, J.-C. and Zhang, X.-Z. (2010). Effect of marine red yeast Rhodosporidium paludigenum on growth and antioxidant competence of Litopenaeus vannamei. Aquaculture, 309: 62-65. [DOI: 10.1016/j.aquaculture.2010.09.032]

Yasin, R., Samiullah, K., Fazal, R. M., Hussain, S., Mahboob, S., & Al-Ghanim, K.A., et al. (2020). Combined effect of probiotics on prolonging the shelf life of GIFT tilapia fillets. Aquaculture Research, 51(12), 5151-5162. [DOI:10.1111/are.14853]

Yousefi, M., Hoseini, S. , Abtahi, B., Vatnikov, Y.A., Kulikov, E. V., & Yurievna, R. N. (2022). Effects of dietary methanolic extract of hyssop, Hyssopus officinalis, on growth performance, hepatic antioxidant, humoral and intestinal immunity, and intestinal bacteria of rainbow trout, Oncorhynchus mykiss. Frontiers in Marine Science, 9, 1026651. [DOI:10.3389/fmars.2022.1026651]

Yousefi, M., Hoseini, S. M., Weber, R. A., da Silva, E., Rajabiesterabadi, H., & Arghideh, M., et al. (2022). Alleviation of transportation-induced stress in Nile tilapia, Oreochromis niloticus, using brackish water. Aquaculture Reports, 27, [DOI:10.1016/j.aqrep.2022.101378]

Yousefi, M., Hoseini, S. M., Kulikov, E. V., Seleznev, S. B., Petrov, A. K., & Babichev, N. V., et al. (2022). Effects of dietary Hyssop, Hyssopus officinalis, extract on physiological and antioxidant responses of rainbow trout, Oncorhynchus mykiss, juveniles to thermal stress. Frontiers in Veterinary Science, 9, [DOI:10.3389/fvets.2022.1042063] [PMID]

Yousefi, M., Ghafarifarsani, H., Raissy, M., Yilmaz, S., Vatnikov, Y. A., & Kulikov, E. V. (2023). Effects of dietary malic acid supplementation on growth performance, antioxidant and immunological parameters, and intestinal gene expressions in rainbow trout, Oncorhynchus mykiss. Aquaculture, 563(1), 738864. [DOI:10.1016/j.aquaculture.2022.738864]

Yousefi, M., Hoseini, S. M., Kulikov, E. V., Babichev, N. V., Bolshakova, M. V., & Shopinskaya, M. I., et al. (2023). Effects of dietary pomegranate peel supplementation on growth performance and biochemical responses of common carp, Cyprinus carpio, to chronic crowding stress. Aquaculture Reports, 30, [DOI:10.1016/j.aqrep.2023.101532]