Search Results (86)

This review examines the status, challenges, and future trajectories of global mussel aquaculture within the blue food system. Despite steady production growth, mussels’ relative contribution to total bivalve output has significantly declined over recent decades due to disproportionate expansion of oyster, clam, and scallop sectors. A major geographical production shift has occurred, with Asia, spearheaded by China, emerging as the dominant region, supplanting traditional European producers while the Americas rapidly ascend. China’s overwhelming dominance in overall bivalve production starkly contrasts with its underdeveloped mussel sector, where growth lags behind other bivalves despite substantial absolute increases, reflecting a fundamental restructuring of species composition. The industry faces interconnected sustainability constraints: persistent vulnerabilities in spat supply stemming from environmental variability, hatchery limitations, and disease transmission risks; escalating environmental stressors including climate change impacts, harmful algal blooms, pollution, and pathogens; structural flaws in value chains characterized by fragmented production, market volatility, and underutilized byproducts; and governance challenges related to spatial access and licensing inefficiencies. This review advocates for a comprehensive strategy to boost the mussel aquaculture. These encompass advancing hatchery technology and genetic breeding programs, implementing ecosystem-based management such as multi-trophic systems and AI-enhanced environmental monitoring, restructuring value chains through producer cooperation and high value product diversification, and establishing science-based spatial planning frameworks with streamlined governance. Addressing these challenges holistically is critical to position mussel farming as a resilient pillar of sustainable blue food production capable of reconciling ecological integrity with economic viability and social equity. Full article

Coral bleaching is a multifactorial stress response in which the breakdown of symbiosis with algal and bacterial partners has been well characterized, but the role of fungal communities remains largely unexplored. Here, we tracked the temporal dynamics of coral-associated fungi in Turbinaria sp. across three defined bleaching stages under natural thermal stress. In total, 161 genera from six phyla were detected. From the unbleached to partly bleached stage, fungal Simpson diversity declined, whereas observed richness slightly increased; putative pathogenic genera (e.g., Apiotrichum, Curvularia, Exserohilum, and Schizophyllum) rose sharply (39.44%→69.04%), whereas parasitic fungi decreased (33.01%→11.72%). From the partly to fully bleached stage, diversity rebounded. Co-occurrence networks became more complex initially (nodes 86→98; edges 454→809; average degree 10.56→16.51) but then collapsed below baseline (nodes 98→65; edges 809→196; average degree 16.51→6.03), indicating stress-driven restructuring. The proportion of positive correlations declined steadily (98.68%→93.82%→77.55%), suggesting a shift toward more competitive and unstable community structures under stress. Our findings demonstrate that fungal communities actively respond to thermal stress and exhibit distinct compositional and ecological shifts during bleaching, pointing to their overlooked but potentially significant role in coral health and deterioration. This study highlights the need to integrate fungal dynamics into the broader understanding of holobiont responses to coral bleaching. Full article

The identification and development of novel antimicrobials is a crucial challenge in the face of increasing antibiotic and antimycotic resistance. As such, there is growing interest in exploring the chemical diversity of natural sources, such as invasive seaweeds such as Asparagopsis armata. The valorization of such sources can further contribute to the development of bio-based industries, aligning with societal goals for environmental and economic sustainability. Therefore, a solid-liquid extraction method was performed using ethanol, and the obtained extract was studied for chemical composition elucidation, bioactivity, and toxicity evaluation. Analysis by GC-MS revealed some major chromatographic peaks, including floridoside (2-α-O-D-galactopyranosyl glycerol), glycerol, and oleamide. Also, several other smaller peaks were tentatively attributed to Low Molecular Weight Carbohydrate Derivatives, including isosaccharino-1,4-lactone, which had only been reported once in nature. The extract demonstrated significant antioxidant activity as measured by Ferric Reducing Antioxidant Potential and Oxygen Radical Absorption Capacity, but not by Lipid Peroxidation Inhibitory Potential assays, which is in line with its polar nature. The extract exhibited antimicrobial activity against various microorganisms, with a MIC of 2 mg/mL observed for Staphylococcus epidermidis, Vibrio parahaemolyticus, and the three yeast strains tested. Moreover, the extract inhibited the growth and phenotypic changes in filamentous fungi, which may result in reduced virulence. Specifically, the extract inhibited sporulation in Aspergillus fumigatus and orange pigmentation in Fusarium graminearum, possibly by a reduction in the production of aurofusarin, rubrofusarin, and mycotoxins. In vitro cell viability assays in 3T3, RAW264.7, and HaCaT demonstrated the extract was not cytotoxic or presented low cytotoxicity at concentrations up to 0.1 mg/mL, but a strong cytotoxic effect was observed at 1 mg/mL. At non-cytotoxic concentrations, the ethanol extract inhibited up to 48% of NO production in LPS-stimulated RAW264.7. This may indicate that anti-inflammatory activity may add to the antimicrobial activity in human and animal systemic and topical applications of the extract. In this work, new molecules were reported in A. armata, and the bioactivities reported were novel for this extract and algal species—especially through the choice of uncommon but very relevant pathogens to study. Our findings are a valuable contribution to addressing challenges in human and animal health, food and feed technology, as well as animal husbandry and agriculture. Full article

The green alga Haematococcus pluvialis, rich in natural astaxanthin, is a key feed additive for salmonid pigmentation. This study evaluated dietary micro-algal astaxanthin effects on structure, antioxidative and immune response, as well as microbiota in different gut segments of rainbow trout Oncorhynchus mykiss (initial average weight: 0.67 ± 0.02 kg). Three diets contained 0 (Diet 1, control), 18.57 (Diet 2) and 31.25 mg/kg (Diet 3) micro-algal astaxanthin. After a 4-month feeding trial, dietary astaxanthin promoted the goblet cell proliferation of pyloric caeca and increased hindgut tunica muscularis thickness (p < 0.05). It also improved antioxidant capacity, characterized by the upregulation of gpx and cat expression in the midgut, accompanied by a significant decrease in MDA content (p < 0.05). Furthermore, dietary astaxanthin could upregulate tgf-β, tor1 and pcna levels in midgut and igm in hindgut, while il1β, il6, il8 and tnfα in hindgut were significantly downregulated in Diet 2 (p < 0.05). Additionally, dietary astaxanthin also enhanced the α-diversity of hindgut and altered the core microbiota (reduced Proteobacteria, increased Actinobacteria). Diet 2 increased microbic abundance associated with reducing gut inflammation and promoting nutrient absorption while decreasing that of pathogenic bacteria. Overall, dietary 18.57 mg/kg astaxanthin supplementation could promote gut structure, antioxidant and immune capacity, reduce inflammation and modulate microbiota. These findings indicate that natural astaxanthin from H. pluvialis has potential as an immunostimulant to promote gut health in salmonids. Full article

Poultry slaughterhouse wastewater (PSW) affects environmental and economic issues, and the introduction of modern treatment technologies, including microalgae-based ones, is strictly necessary. In this study, bioremediation of unsterilized PSW by several algal representatives of the genera Chlorella, Tetradesmus, Desmodesmus, and Neochloris was investigated. All microalgae grew in original wastewater, and the elevated N, P, and S levels in PSW allowed the microalgae to increase the biomass yield (from 2.44–3.15 to 2.73–4.42 g L⁻¹). Modification of PSW for cultivation of microalgae made it possible to obtain biomass with a high content of valuable metabolites. The highest protein content was observed in cells of cultures of Chlorella sorokiniana and Neochloris sp. (26% and 33% of the final dry weight, respectively). At the same time, starch and lipids were also accumulated in the algal cells at substantial levels in both original and modified PSW. With the growth of algae, a decrease in the relative abundance of members of Arcobacteraceae and Clostridium, which include pathogens, was also observed. At the same time, PSW contained a variety of bacteria capable of stimulating the growth of microalgae. Thus, integrating microalgae into the treatment of PSW will reduce the negative impact of such wastewaters on the environment and improve the sanitary indicators. Full article

Anaerobic digestion piggery effluent (ADPE), dark brown with high turbidity and ammonium, inhibits algal growth and requires pretreatment for cultivation. This study compared various physical/biological pretreatment methods for microalgae cultivation. The results showed that the strategy of 10%ADPE fungal cultivation (10%AF) pretreatment and subsequent microalgae cultivation achieved maximum specific growth rate (0.094 d⁻¹) with productivity (0.014 g L⁻¹ d⁻¹) and significant nutrient removal: 100% ammonium nitrogen, 99% total nitrogen, 63% total phosphorus, 91% chemical oxygen demand. However, the pathogenic fungus used poses safety risks, requiring future screening of eco-friendly alternatives. This study demonstrated that the strategy could be a promising approach to algal biomass production and nutrient removal from ADPE. Full article

Methicillin-resistant Staphylococcus aureus (MRSA), a multidrug-resistant pathogen, poses a significant threat to global healthcare. This review evaluates the potential of marine algal metabolites as novel antibacterial agents against MRSA. We explore the clinical importance of S. aureus, the emergence of MRSA as a “superbug”, and its resistance mechanisms, including target modification, drug inactivation, efflux pumps, biofilm formation, and quorum sensing. The limitations of conventional antibiotics (e.g., β-lactams, vancomycin, macrolides) are discussed, alongside the promise of algal-derived compounds such as fatty acids, pigments, polysaccharides, terpenoids, and phenolic compounds. These metabolites exhibit potent anti-MRSA activity by disrupting cell division (via FtsZ inhibition), destabilizing membranes, and inhibiting protein synthesis and metabolic pathways, effectively countering multiple resistance mechanisms. Leveraging advances in algal biotechnology, this review highlights the untapped potential of marine algae to drive innovative, sustainable therapeutic strategies against antibiotic resistance. Full article

Mastitis is a common condition in dairy cattle that causes huge losses globally. The inflammation is caused by the invasion of the teat canal by pathogens, including hard-to-control single-cell microalgae of the genus Prototheca. The aim of the study was the in vitro comparison of the antimicrobial properties of 10 selected essential oils (EOs) and amphotericin B (AMB) against Prototheca bovis strains (PRO3 and PRO7) from different regions in Poland. The antialgal effect was estimated by using toxicity tests. The chemical composition of the EOs was determined by using gas chromatography coupled with mass spectrometry. The tested EOs had significant cytotoxic effects on algal viability. A statistical analysis of the results revealed that the highest biocidal potential, at a concentration of 2%, was demonstrated by lavender, rosemary, and oregano oils, reducing the survival of the Prototheca bovis strains, on average, by 51.21%, 45.83%, and 45.15%, respectively. In comparison, AMB reduced algal viability by an average of 88% compared with the control groups. Further research into the utilization of the biocidal properties of lavender, rosemary, and oregano oil against Prototheca spp. may help to develop new forms of treatments against mastitis caused by this pathogen in the future. Full article

Biofilms are structurally organized communities of microorganisms that adhere to a variety of surfaces. These communities produce protective matrices consisting of polymeric polysaccharides, proteins, nucleic acids, and/or lipids that promote shared resistance to various environmental threats, including chemical, antibiotic, and immune insults. While algal and bacterial biofilms are more apparent in the scientific zeitgeist, many fungal pathogens also form biofilms. These surprisingly common biofilms are morphologically distinct from the multicellular molds and mushrooms normally associated with fungi and are instead an assemblage of single-celled organisms. As a collection of yeast and filamentous cells cloaked in an extracellular matrix, fungal biofilms are an extreme threat to public health, especially in conjunction with surgical implants. The encapsulated yeast, Cryptococcus neoformans, is an opportunistic pathogen that causes both pulmonary and disseminated infections, particularly in immunocompromised individuals. However, there is an emerging trend of cryptococcosis among otherwise healthy individuals. C. neoformans forms biofilms in diverse environments, including within human hosts. Notably, biofilm association correlates with increased expression of multiple virulence factors and increased resistance to both host defenses and antifungal treatments. Thus, it is crucial to develop novel strategies to combat fungal biofilms. In this review, we discuss the development and treatment of fungal biofilms, with a particular focus on C. neoformans. Full article

Water treatment technologies have received great attention recently, as water is the most important nutritional element, and animals consume it daily in larger quantities than those of food. The ideal water treatment affects the chemical composition and physical properties of water, having a significant positive impact on the animal’s physiology, productivity, and welfare. Studies conducted on water ionization devices for broiler chickens remain limited; therefore, this study was planned to investigate the effect of ionized drinking water on the productive performance, physiological status, and carcass characteristics of broiler chicks. A total of 900 one-day-old broiler chicks were randomly and equally assigned to three groups, each with six replicates (50 birds/replicate). The first group (C) received tap drinking water and served as a control, while the second group (T1) received ionized drinking water from an ionizing device that worked for 1 h/100 L. The third group (T2) received ionized drinking water from an ionizing device that worked for 2 h/100 L. Water analysis for each treatment was performed. Productive traits, such as weekly body weight, feed intake, and water intake, were recorded. Hematological parameters and biochemical constituents were measured according to the reference’s description. Furthermore, carcass characteristics, such as carcass weight and dressing percentage, and bacterial count of the intestine, such as Lactobacilli and Coliform counts, were determined. From the results, ionized water (T1 and T2) had a negative ORP, which is often desirable as it suggests the presence of antioxidant properties and lower total dissolved solids (TDSs), heterotrophic plate count (HPC), and algal total count (ATC) than in tap water. The treated chicks showed higher final body weights and better feed conversion rates than the control. Ionized water also improved carcass quality characteristics, such as carcass weight and dressing percentage. T1 and T2 chicks exhibited higher hemoglobin, total protein, globulin, G and M immunoglobulin, and total antioxidant capacity (TAC) levels, as well as lower malondialdehyde (MDA) and low-density lipoprotein (LDL) levels than the control. Furthermore, they had lower pathogenic bacteria counts. Therefore, it is recommended to employ the ionizing approach for broiler chicken drinking water, particularly a 2 h/100 L ionization application, for better animal productivity, health, and welfare. Full article

Background: Lake Al-Asfar in KSA was used as a sink for wastewater for decades and suffered from pollution. The lake is a habitat to different microbial species that play important ecological roles, some of which are good, and some are bad and even pathogenic. In a previous investigation, algal-bacteria consortia have proven to be beneficial in bioremediating heavy metals and hydrocarbons in Lake Al-Asfar. The identity of algae was revealed to be Chlorella sp. and Geitlernema sp. in the consortia. The identity of the heterotrophic bacterial partners, on the other hand, awaits investigation and is addressed in the present research. On the other hand, investigating the diversity of Protozoa and parasites is also tackled as they represent indicators of pollution. Some pose serious health risks, but some of them also contribute to reducing some of the pollution levels. Methods: Bacteria associated with algae were isolated in pure form. The polyphasic approach was used to identify bacterial samples, including staining procedures, the use of Vitek technology, and scanning electron microscopy. This information was integrated with structure information such as capsule presence, endospore formation, and wall characteristics indicated by Gram stain. With regard to protists including Protozoa and parasites, Light microscopy and taxonomic books of identification were used to reveal their identity. Results: three main bacterial strains belonging to the following genera were identified: Sphingomonas, Rhizobium, and Enterbacter. The last is potentially pathogenic and poses health risks to Lake goers. Rhizobium, on the other hand, is most likely found in the lake from agricultural wastewater and is a nitrogen fixer that increases the fertility of crops. The first bacterium is associated with special lipid metabolism and is hardly pathogenic. Several diverse microscopic forms of protists, mainly Protozoa and parasites, were identified, which included Entamoeba histolytica, Balantidium coli, Ascaris lumbricoides, Amoeba, Paramecium, Euglena, and Gymnodinium sp. Discussion: The three types of bacteria identified have metabolic activities that are associated with bioremediation. On the other hand, protists, including Protozoa and parasites, are regular members of wastewater communities and help in scavenging solid wastes, but they cause hazards such as secreting toxins, causing disease, and impacting the bioremediation potential by feeding on beneficial bioremediating algae and bacteria. This is part of the wastewater ecosystem dynamics, but efforts must be exerted to minimize, if not completely eliminate, pathogenic parasites in order to maximize the growth of algal consortia. Conclusions: Vitek technology is an emerging less time- and effort-consuming fast technology for identifying bacteria. Bacteria identified have significant ecological bioremediating roles, together with their algal partners, but some pose pathogenic risks. Identifying co-inhabitants like protists and parasites helps to shed light on their impact on one another and pave the way for restoration efforts that minimize the biological hazards and maximize the use of beneficial local microorganisms. Full article

Tourism still represents a means of generating revenues in the coastal areas in the Mexican Caribbean, despite the growing concern about the social and environmental impacts. The Nichupte Lagoon System (NLS), the most representative lagoon of Quintana Roo State for being in the middle of Cancun’s hotel development, has experienced a continuous drop-off in its water quality due to several factors, including dredging and wastewater discharges from different anthropogenic activities, which modify the flux of nutrients, increase the number of pathogenic microorganisms, and promote physicochemical changes in this ecosystem. Three sampling campaigns (2018, 2019, and 2020) were carried out in the NLS in August, which is the month of greatest tourist occupancy. To evidence the presence of anthropogenic wastewater in the NLS, the caffeine tracer was used, and to determine the water quality, 43 sampling stations were monitored for “in situ” physicochemical parameters (salinity and dissolved oxygen), and water samples were collected for the quantification of nutrients (NO₂⁻ + NO₃⁻, NH₄⁺, SRP and SRSi) and chlorophyll-a (Chl-a). For data analysis, the lagoon was subdivided into five zones (ZI, ZII, ZIII, ZIV, and ZV). Caffeine spatial and time variation evidence (1) the presence of anthropogenic wastewater in all areas of the NLS probably resulting from the tourist activity, and (2) wastewater presence is directly influenced by the coupling of the hydrological changes driven by anomalous rain events and the number of tourists. This same tendency was observed for nutrients that increased from 2018 to 2019 and the trophic state changed from oligotrophic to hypertrophic in all areas, as a result of previous anomalous precipitations in 2018, followed by normal precipitations in 2019. From 2019 to 2020, the nutrients decreased due to the drop in tourism due to COVID-19, promoting fewer nutrients in the lagoon, but, also coupled with an anomalous precipitation event (Cristobal storm), resulted in a dilution phenomenon and an oligotrophic state. The cluster analysis indicated that the least similar zones in the lagoon were the ZI and ZV due to their geomorphology that restricts the connection with the rest of the system. Principal component analysis revealed that wastewater presence evidenced by the caffeine tracer had a positive association with dissolved oxygen and chlorophyll-a, indicating that the arrival of nutrients from wastewater amongst other sources promotes algal growth, but this could develop into an eutrophic or hypertrophic state under normal precipitation conditions as seen in 2019. This study shows the relevance of monitoring in time of vulnerable karstic systems that could be affected by anthropogenic contamination from wastewater inputs, stressing the urgent need for efficient wastewater treatment in the area. The tourist industry in coastal karstic lagoons such as the NLS must have a Wastewater Treatment Program as a compensation measure for the anthropic pressure that is negatively changing the water quality of this highly relevant socio-environmental system. Full article

The exploration of natural antifungal substances from algal origins is significant due to the increasing resistance of pathogens to conventional antifungal agents and the growing consumer demand for natural products. This manuscript represents the inaugural investigation into the antifungal attributes of bioactive compounds extracted from Fucus vesiculosus via supercritical carbon dioxide (scCO₂) extraction utilizing contemporary countercurrent chromatography (CCC). In aligning with the prospective utilization of this extract within the agricultural sector, this study also serves as the preliminary report demonstrating the capability of Fucus vesiculosus scCO₂ extract to enhance the activity of plant resistance enzymes. The fractions obtained through CCC were subjected to evaluation for their efficacy in inhibiting the macrospores of Fusarium culmorum. The CCC methodology facilitated the successful separation of fatty acids (reaching up to 82.0 wt.% in a given fraction) and fucosterol (attaining up to 79.4 wt.% in another fraction). All CCC fractions at the concentration of 1.0% were found to inhibit 100% of Fusarium culmorum growth. Moreover, Fucus vesiculosus scCO₂ extract was able to activate plant resistance enzymes (Catalase, Ascorbic Peroxidase, Guaiacol Peroxidase, Phenylalanine Ammonia-Lyase, and Phenylalanine Ammonia-Lyase Activity). Full article

Antibiotic resistance in cyanobacteria represents a global threat to public health. The widespread presence of cyanobacteria in aquatic environments exposes them to antibiotic contamination. Cyanobacteria are also in direct contact with pathogenic bacteria containing antibiotic-resistance genes (ARGs), which impart these characteristics to them. This study aims to examine the presence of some ARGs in locally isolated cyanobacteria species, Spirulina laxa, Chroococcus minutes, Oscillatoria princeps, Oscillatoria proteus, Oscillatoria terebriformis, and Lyngbya epiphytica, and compare the presence of these genes in two pathogenic bacteria, Escherichia coli and Klebsiella pneumoniae. Ampicillin (Ap) and erythromycin (Em) resistance genes were detected in five algal samples. Meanwhile, Chloramphenicol (Cm) and gentamicin (Gm) resistance genes were apparent in only two species. Genes encoding resistance towards kanamycin (Km) and spectinomycin (Sp) were recorded in three specimens. It was also found that E. coli possessed resistance genes for four antibiotics, ampicillin (Ap), erythromycin (Em), gentamicin (Gm), and kanamycin (Km), whereas K. pneumoniae was resistant towards three antibiotics, ampicillin (Ap), gentamicin (Gm), and kanamycin (Km). The results show that there is a match in antibiotic-resistance genes in both cyanobacteria and pathogenic bacteria. Suggesting the possibility that cyanobacteria could acquire ARGs from the environment through horizontal gene transfer. Thus, freshwater cyanobacteria may play a significant role in the prevalence of ARGs in their environment. Full article

Background: Glyoxal has been implicated as a significant contributor to the formation of secondary organic aerosols, which play a key role in our ability to estimate the impact of aerosols on climate. Elevated concentrations of glyoxal over open ocean waters suggest that there exists an additional source, different from urban and forest environments, which has yet to be identified. Methods: Based on mass spectrometric analyses of nascent sea spray aerosols (SSAs) and gas-phase molecules generated during the course of a controlled algal bloom, the work herein suggests that marine microorganisms are capable of excreting toluene in response to environmental stimuli. Additional culture flask experiments demonstrated that pathogenic attack could also serve as a trigger for toluene formation. Using solid-phase microextraction methods, the comparison of samples collected up-channel and over the breaking wave suggests it was transferred across the air–water interface primarily through SSA formation. Results: The presence and then absence of phenylacetic acid in the SSA days prior to the appearance of toluene support previous reports that proposed toluene is produced as a metabolite of phenylalanine through the Shikimate pathway. As a result, once in the atmosphere, toluene is susceptible to oxidation and subsequent degradation into glyoxal. Conclusions: This work adds to a minimal collection of literature that addresses the primary production of aromatic hydrocarbons from marine microorganisms and provides a potential missing source of glyoxal that should be considered when accounting for its origins in remote ocean regions. Full article