Aquaculture is the fastest-growing food production sector. However, it faces significant challenges, including demand from a growing global population, which is estimated to reach 10.4 billion by the year 2100, disease outbreaks, environmental impacts, and the overuse of antibiotics. To address these issues, sustainable alternatives such as the use of microorganisms (probiotics, bacteriophages, and genetically modified microorganisms) have gained attention. This review examines the effects of these microorganisms on fish aquaculture, focusing on their potential to improve growth, health, and disease resistance while reducing environmental impacts. Probiotics, particularly lactic acid bacteria and yeasts, have been shown to enhance immune responses, digestive enzyme activity, and nutrient absorption in fish. Bacteriophages offer a promising alternative to antibiotics for controlling bacterial pathogens, with studies demonstrating their efficacy in reducing mortality rates in infected fish. Additionally, genetically modified microorganisms (GMMs) have been explored for their ability to produce beneficial compounds, such as enzymes and antimicrobial peptides, which can improve fish health and reduce the need for chemical treatments. Despite their potential, challenges such as regulatory hurdles, public acceptance, and environmental risks must be addressed. This review highlights the importance of further research to optimize the use of microorganisms in aquaculture and underscores their role in promoting sustainable practices. By integrating these biological tools, the aquaculture industry can move towards a more sustainable and environmentally friendly future.

Continued human population growth has resulted in increased demand for products, including those derived from aquaculture. The main challenge in aquaculture is producing more every year. In recent years, environmentally friendly supplements that provide the necessary pathways for optimal production have been emphasized. One of them is prebiotics, selectively utilized substrates by host microorganisms conferring a health benefit. Interest in applying prebiotics in global fish farming has increased in recent years as it has been shown to improve growth, boost the immune system, resist stress conditions, and cause the modulation of digestive enzymes. These effects reflect reduced production and disease costs. However, in Latin American countries such as Mexico, large-scale use of these food supplements is needed as a sustainable alternative to improve fish production. This paper gives a review of the current advances obtained with the application of prebiotics in commercially farmed fish worldwide, mentions the prebiotics to use in the aquaculture industry, and updates the status of studies about the used prebiotics in global commercial fish cultivated in Mexico, as well as freshwater and marine endemic fish in this country. Also, the limitations of prebiotics application in terms of their use and legislation are analyzed.

A method was developed to determine glyphosate, aminomethylphosphonic acid (AMPA), and glufosinate in soil. The worldwide use of this herbicide in agricultural activities, and its known negative effects on both the environment and health, have generated interest in the establishment of methodologies for its determination in several matrices at trace level. The development of analytical methods for the determination of glyphosate, AMPA, and glufosinate is challenging due to its present amphoteric properties, high solubility in water, low molecular weight, high affinity to the ions presents in the soil, and lack of chromophore groups in its structure, making its quantification difficult. The proposed method exhibits a linear range from 5.0 to 600 µg/kg with limits of detection of 1.37, 0.69 and 1.22 μg/kg, limits of quantification of 4.11, 2.08, and 3.66 μg/kg for glyphosate, AMPA, and glufosinate, respectively, and adequate repeatability and reproducibility (coefficients of variation <8.0% and recovery percentages between 93.56% and 99.10%). The matrix effect was calculated for each analyte, proving to be a good alternative for the determination of these contaminants. The described method was applied to 46 soil samples collected from crop fields in Hidalgo, Mexico, with concentrations varying from not detected to 4.358 μg/kg (for AMPA).

Water contamination with pesticides is one of the major pollution problems in northwestern Mexico, and this is due to the extensive use of pesticides in agriculture. In this research, water samples of ten sampling sites (fishing grounds, beaches, and both) were analyzed in the search for 28 pesticides (organochlorines, organophosphates, pyrethroids, carbamates, among other chemical classes), supplemented with a calculation of the resulting potential environmental risk. Pesticides were separated from the matrix by liquid-liquid extraction and quantified by gas chromatography coupled to electron micro-capture (organohalogenated) and pulsed flame photometric detectors (organophosphates). In addition, the ecotoxicological risk of pesticides in algae, invertebrates, and fish was assessed, based on seawater pesticide concentrations using the Risk Quotient (RQ) and Toxic Units (TU) approach. The results showed 18 pesticides identified in the analyzed samples, where cypermethrin and chlorpyrifos were identified with the maximum concentrations of 1.223 and 0.994 μg L^-1, respectively. In addition, these two pesticides have been associated with acute toxic effects on algae, invertebrates, and fish. It is important to pay particular attention to the search for long-term alternatives to the use of chlorpyrifos and cypermethrin due to their high detection rates and the risks associated with their toxic properties. However, the adoption of alternative measures to synthetic pesticide control should be a priority, moving towards sustainable practices such as the use of biopesticides, crop rotation and polycultures.

Teleost fish are the most diverse group of extant vertebrates and have varied digestive anatomical structures and strategies, suggesting they also possess an array of different host-microbiota interactions. Differences in fish gut microbiota have been shown to affect host development, the process of gut colonization, and the outcomes of gene-environment or immune system-microbiota interactions. There is generally a lack of studies on the digestive mechanisms and microbiota of agastric short-intestine fish however, meaning that we do not understand how changes in gut microbial diversity might influence the health of these types of fish. To help fill these gaps in knowledge, we decided to study the Mexican pike silverside (Chirostoma estor) which has a simplified alimentary canal (agastric, short-intestine, 0.7 gut relative length) to observe the diversity and metabolic potential of its intestinal microbiota. We characterized gut microbial populations using high-throughput sequencing of the V3 region in bacterial 16S rRNA genes while searching for population shifts resulting associated with fish development in different environments and cultivation methods. Microbiota samples were taken from the digesta, anterior and posterior intestine (the three different intestinal components) of fish that grew wild in a lake, that were cultivated in indoor tanks, or that were raised in outdoor ponds. Gut microbial diversity was significantly higher in wild fish than in cultivated fish, suggesting a loss of diversity when fish are raised in controlled environments. The most abundant phyla observed in these experiments were Firmicutes and Proteobacteria, particularly of the genera Mycoplasma, Staphylococcus, Spiroplasma, and Aeromonas. Of the 14,161 OTUs observed in this experiment, 133 were found in all groups, and 17 of these, belonging to Acinetobacter, Aeromonas, Pseudomonas, and Spiroplasma genera, were found in all samples suggesting the existence of a core C. estor microbiome. Functional metagenomic prediction of bacterial ecological functions using PICRUSt2 suggested that different intestinal components select for functionally distinct microbial populations with variation in pathways related to the metabolism of amino acids, vitamins, cofactors, and energy. Our results provide, for the first time, information on the bacterial populations present in an agastric, short-gut teleost with commercial potential and show that controlled cultivation of this fish reduces the diversity of its intestinal microbiota.

La biotecnología acuícola se basa en el conocimiento generado por investigaciones científicas multidisciplinarias aplicadas a la producción de organismos acuáticos. Las enfermedades infecciosas, el cambio climático y la sostenibilidad, son los principales retos actuales de la acuicultura. En este trabajo se hace una revisión de las posibles soluciones biotecnológicas a estos retos, a través del mejoramiento de las dietas, del uso de nuevas tecnologías de análisis, como son las ciencias ómicas y finalmente se discute la integración de especies nativas a la acuicultura. Todas estas actividades, con políticas públicas adecuadas, promoverán el desarrollo de una acuicultura más rentable, sostenible y acorde con las condiciones regionales, garantizando la seguridad alimentaria.