A mini-review on co-supplementation of probiotics and medicinal herbs: Application in aquaculture

Unveiling tyrosinase inhibition: exploring secondary metabolites from Fernandoa adenophylla through biological screening and molecular docking

The current study investigated the tyrosinase inhibitory activity of compounds extracted from Fernandoa adenophylla, complemented by in silico analysis. Using methanolic extract and chromatography, several compounds were isolated and tested for their inhibitory effects against human and mushroom tyrosinase enzymes. The indanone derivative (Sample CC) emerged as the most potent inhibitor, demonstrating 96.32% inhibition with an IC50 of 6.2 ± 0.9 µg/mL against human tyrosinase and 91.3% inhibition with an IC50 of 1.8 ± 0.5 µg/mL against mushroom tyrosinase, surpassing the standard inhibitor, Kojic acid. In silico docking studies further supported these findings, revealing strong binding interactions between Sample CC and the active site of the tyrosinase, suggesting a robust inhibition mechanism. The analysis of interaction plots showed that the isolated compounds interact with key amino acid residues. These results highlight the potential of F. adenophylla compounds as natural tyrosinase inhibitors, offering promising alternatives for therapeutic and cosmetic applications.

Isolation, characterization of Bacillus subtilis and Bacillus amyloliquefaciens and validation of the potential probiotic efficacy on growth, immunity, and gut microbiota in hybrid sturgeon (Acipenser baerii ♀ × Acipenser schrenckii ♂)

Probiotics are increasingly considered as an alternative to antibiotics in developing environmentally sustainable aquaculture practices. Hybrid sturgeon (Acipenser baerii ♀ × Acipenser schrenckii ♂), a globally popular species valued for its nutritional content and caviar, has limited research on host-associated probiotics. In this study, we isolated and identified Bacillus subtilis and Bacillus amyloliquefaciens from healthy hybrid sturgeon and assessed their impact on growth, immunity, gut microbiota, and transcriptome following an 8-week feeding trial. The isolated strains demonstrated strong production of protease, amylase, lipase, and cellulase, along with broad-spectrum pathogen inhibition, including Aeromonas veronii, Aeromonas sobria, and Yersinia ruckeri. Supplementation with B. subtilis and B. amyloliquefaciens significantly improved growth performance and increased survival rates against A. veronii infection. Mechanistically, probiotics altered gut microbiota composition, enhancing digestive functions. Transcriptome analysis further revealed that probiotic supplementation boosted immune response and protein digestion and absorption. These findings suggest that B. subtilis and B. amyloliquefaciens are promising probiotic candidates for the hybrid sturgeon industry, offering effective protection against A. veronii infection.

A glimpse on influences of ginger and its derivatives as a feed additive in finfish farming: A mini-review

Ginger (Zingiber officinale) has emerged as a promising feed additive in aquaculture due to its reported benefits for fish health and growth. Possessing a range of bioactive compounds, ginger exhibits antimicrobial, anti-parasite, immunostimulatory, anti-inflammatory, anti-oxidative, and growth-promoting properties. This review provides a comprehensive overview of recent research on dietary ginger and its derivatives for fish. It explores the various forms, bioactive compounds, biological activities, and preparation methods of these feed additives. The discussion focuses on the impacts of dietary ginger and its derivatives on growth performance, flesh quality, hematology profile, antioxidative responses, immune system, and disease resistance stimulation in fish. Additionally, the review examines the mechanisms of action of these additives and explores the optimal supplementation levels for inclusion in fish diets. Previous studies reported the optimal doses of dietary ginger and its derivatives were ranged from 0.0002 to 4 % of diet whereas 0.0004 % for bathing treatment. Bioactive compounds such as phenolic acids, flavonoids, zingerone, gingerols, shogaols, and paradols were responsible to the ginger and its derivatives beneficial effects. Overall, the findings suggest that dietary ginger and its derivatives hold significant promise for enhancing growth and health in fish farming.

Marine microalgae and their industrial biotechnological applications: A review

BACKGROUND

For use in specialized programs in the food, pharmaceutical, nutraceutical, cosmetic, and animal feed sectors, micro-algal biomass has been generated industrially. They can be grown in closed buildings, such as photobioreactors, or open structures. The utilization of biomass from microalgae for energy production is another crucial topic. Because of the world's diminishing petroleum sources and the greenhouse gas emissions from gasoline lines, it is now obvious that fuels generated from petroleum are not sustainable.

RESULTS

Microalgae can produce a variety of unique, sustainable biofuels. These include biodiesel made from trans-esterification of microalgal lipids, bioethanol from fermentation of carbohydrates, methane created by anaerobic digestion of algal biomass, and biohydrogen produced by photobiological processes. The idea of using microalgae as a fuel source is not entirely novel.

CONCLUSION

This analysis emphasizes the significance of recent and noteworthy advancements in the industrial usage of microalgae, with an emphasis on their biotechnological applications.

Probiotics for Aquaculture: Hope, Truth, and Reality

The use of microorganisms as beneficial crops for human and animal health has been studied for decades, and these microorganisms have been in practical use for quite some time. Nowadays, in addition to well-known examples of beneficial properties of lactic acid bacteria, bifidobacteria, selected Bacillus spp., and yeasts, there are several other bacteria considered next-generation probiotics that have been proposed to improve host health. Aquaculture is a rapidly growing area that provides sustainable proteins for consumption by humans and other animals. Thus, there is a need to develop new technologies for the production practices associated with cleaner and environment-friendly approaches. It is a well-known fact that proper selection of the optimal probiotics for use in aquaculture is an essential step to ensure effectiveness and safety. In this critical review, we discuss the evaluation of host-specific probiotics in aquaculture, challenges in using probiotics in aquaculture, methods to improve the survival of probiotics under different environmental conditions, technological approach to improving storage, and delivery along with possible negative consequences of using probiotics in aquaculture. A critical analysis of the identified challenges for the use of beneficial microbes in aquaculture will help in sustainable aquafarming, leading to improved agricultural practices with a clear aim to increase protein production.

Effects of dietary powdered Ficus deltoidea on the growth and health performance of African catfish, Clarias gariepinus production

Intensive aquaculture causes a decline in the health status of fish, resulting in an increased disease incidence. To counteract this, feed additives have been utilized to improve the growth performance and health of aquaculture species. This work specifically investigates the impact of powdered Ficus deltoidea (FD) on various parameters related to growth, blood parameters, liver and intestine morphology, body proximate analysis, digestive enzymes, antioxidant capacity, and disease resistance to motile Aeromonad Septicemia (MAS) caused by Aeromonas hydrophila infection in African catfish, Clarias gariepinus. Four formulated diets were prepared: T1 (0% FD), T2 (0.5% FD), T3 (0.75% FD), and T4 (1% FD). After 8 weeks, the African catfish's growth performance fed with the T2 diet exhibited a substantial improvement (p < 0.05), along with a remarkably lower (p < 0.05) feed conversion ratio (FCR) when compared to the other treatment groups. Blood parameter analysis revealed notably higher (p < 0.05) levels of white blood cell (WBC), lymphocytosis (LYM), hemoglobin (HGB), albumin (ALB), globulin (GLOB), as well as total protein (TP) in the T2 diet group. While all treatment groups displayed normal intestinal morphology, liver deterioration was observed in groups supplemented with higher FD. The T2 diet group recorded the highest villus length, width, and crypt depth. Protease and lipase levels were also notably improved in the T2 diet group compared to other treatment groups. Additionally, catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) were remarkably elevated in all FD diet groups than in the control group. The expression of immune-related genes, including transforming growth factor beta 1, heat shock protein 90, nuclear factor kappa-B gene, and lysozyme G, was upregulated in all treatments. Overall, the results of this study indicate that incorporating dietary FD at 0.5% concentration in the diet of African catfish may enhance their productivity in intensive farming.

Role of Phytobiotics in Modulating Transcriptomic Profile in Carps: A Mini-Review

Carp is a key aquaculture species worldwide. The intensification of carp farming, aimed at meeting the high demand for protein sources for human consumption, has resulted in adverse effects such as poor water quality, increased stress, and disease outbreaks. While antibiotics have been utilized to mitigate these issues, their use poses risks to both public health and the environment. As a result, alternative and more sustainable practices have been adopted to manage the health of farmed carp, including the use of probiotics, prebiotics, phytobiotics, and vaccines to prevent disease outbreaks. Phytobiotics, being both cost-effective and abundant, have gained widespread acceptance. They offer various benefits in carp farming, such as improved growth performance, enhanced immune system, increased antioxidant capacity, stress alleviation from abiotic factors, and enhanced disease resistance. Currently, a focal point of research involves employing molecular approaches to assess the impacts of phytobiotics in aquatic animals. Gene expression, the process by which genetic information encoded is translated into function, along with transcription profiling, serves as a crucial tool for detecting changes in gene expression within cells. These changes provide valuable insights into the growth rate, immune system, and flesh quality of aquatic animals. This review delves into the positive impacts of phytobiotics on immune responses, growth, antioxidant capabilities, and flesh quality, all discerned through gene expression changes in carp species. Furthermore, this paper explores existing research gaps and outlines future prospects for the utilization of phytobiotics in aquaculture.

Exploring beneficial effects of phytobiotics in marine shrimp farming: A review

Marine shrimp farming, mainly Penaeus monodon and Litopenaeus vannamei, is an important component of the aquaculture industry. Marine shrimp farming helps produce a protein source for humans, provides job opportunities, and generates lucrative profits for investors. Intensification farming practices can lead to poor water quality, stress, and malnutrition among the farmed marine shrimp, resulting in disease outbreaks and poor production, impeding the development of marine shrimp farming. Antibiotics are the common short-term solution to treat diseases in marine shrimp farming. Moreover, the negative impacts of using antibiotics on public health and the environment erode consumer confidence in aquaculture products. Recently, research on using phytobiotics as a prophylactic agent in aquaculture has become a hot topic. Various phytobiotics have been explored to reveal their beneficial effects on aquaculture species. In this review paper, the sources and modes of action of phytobiotics are presented. The roles of phytobiotics in improving growth performance, increasing antioxidant capacity, enhancing the immune system, stimulating disease resistance, and mitigating stress due to abiotic factors in marine shrimp culture are recapitulated and discussed.

Exploring the potential of black fungus, Auricularia auricula, as a feed additive in African catfish, Clarias gariepinus, farming

This study explores the beneficial effects of Auricularia auricula (AA) as a feed additive in promoting growth, digestive enzyme activities, antioxidative responses, heat tolerance, and disease resistance against Edwardsiella tarda in African catfish (Clarias gariepinus) farming. The application of feed additives is a hot topic in recent aquaculture studies aimed at promoting the growth and health of aquaculture species. After 8 weeks of feeding trial, the results of the present study revealed that fish-fed AA diets performed significantly better (p < 0.05) compared to the control group in growth performances, including final weight, weight gain, and specific growth rate. The highest performances were observed in the fish-fed AA at 3 and 4 %. A similar trend was also observed in the values of feed conversion ratio, hepatosomatic index, and visceral somatic index, with the lowest values (p < 0.05) in the fish-fed AA at 3 and 4 %. AA diets enhanced the activities of all tested digestive enzymes (amylase, protease, and lipase) significantly (p < 0.05), with the highest activities in the fish-fed AA at 3 and 4 %. Meanwhile, fish-fed AA diets exhibited significantly higher (p < 0.05) catalase, superoxide dismutase, and glutathione peroxidase activities both before and after heat stress, with the highest activities in the fish that received AA at 3 and 4 %. Furthermore, AA diets stimulated disease resistance in African catfish, with the fish-fed AA at 4 % performing the highest cumulative survival rate (73.3 ± 5.77 %) post-infection with E. tarda in African catfish. The findings of the current study suggest that AA has huge potential as a feed additive in African catfish farming.

Resveratrol impacts on aquatic animals: a review

Aquaculture has intensified tremendously with the increasing demand for protein sources as the global population grows. However, this industry is plagued with major challenges such as poor growth performance, the lack of a proper environment, and immune system impairment, thus creating stress for the aquaculture species and risking disease outbreaks. Currently, prophylactics such as antibiotics, vaccines, prebiotics, probiotics, and phytobiotics are utilized to minimize the negative impacts of high-density farming. One of the promising prophylactic agents incorporated in fish feed is resveratrol, a commercial phytophenol derived via the methanol extraction method. Recent studies have revealed many beneficial effects of resveratrol in aquatic animals. Therefore, this review discusses and summarizes the roles of resveratrol in improving growth performance, flesh quality, immune system, antioxidant capacity, disease resistance, stress mitigation, and potential combination with other prophylactic agents for aquatic animals.

Microbial community structure and diversity in fish-flower (mint) symbiosis

The fish-flower symbiosis model is an eco-friendly sustainable farming technology combining plants, fish and microorganisms in a recirculating aquaculture system. However, there are few studies on the structure and diversity of microbial communities in fish intestines, culture water and plant roots during fish-flower symbiosis. Here, we cultured carp (Cyprinus carpio), crucian carp (Carassius auratus) and grass carp (Ctenopharyngodon idella) with mint (Mentha spicala L.) and extracted total genomic DNA from intestinal microorganisms, culture-water microorganisms and root microorganisms for each fish species for high-throughput sequencing of 16S rRNA genes. Analysis of microbial community structure and diversity revealed changes in abundance of microbial genera in the intestines and culture water of each fish species, including changes in the dominant taxa. Pirellula, Truepera, Aquincola, Cetobacterium and Luteolibacter were widespread in the fish intestine, culture water and mint root system. This study revealed the effects of mint feeding on the structure and diversity of microbial communities of fish, water bodies and the mint root system during fish-flower symbiosis, providing a theoretical reference for the promotion and application of fish-flower (mint) symbiosis technology and healthy fish culture technology.