Search Results (55)

The crude ethyl acetate extract of the culture of a marine sponge-associated fungus, Aspergillus unguis KUFA 0098, was tested for its capacity to inhibit the growth of ten phytopathogenic fungi, viz. Alternaria brassicicola, Bipolaris oryzae, Colletotrichum capsici, Curvularia oryzae, Fusarium semitectum, Lasiodiplodia theobromae, Phytophthora palmivora, Pyricularia oryzae, Rhizoctonia oryzae, and Sclerotium roflsii. At a concentration of 1 g/L, the crude extract was most active against P. palmivora, causing the highest growth inhibition (55.32%) of this fungus but inactive against R. oryzae and S. roflsii. At a concentration of 10 g/L, the crude extract completely inhibited the growth of most of the fungi, except for L. theobromae, R. oryzae, and S. roflsii, with 94.50%, 74.12%, and 67.80% of inhibition, respectively. The crude extract of A. unguis KUFA 0098 exhibited growth-inhibitory effects against B. oryzae and P. oryzae, causative agents of brown leaf spot disease and leaf blast disease, respectively, on rice plant var. KDML105, under greenhouse conditions. Chromatographic fractionation and purification of the extract led to the isolation of four previously described depsidones, viz. unguinol (1), 2-chlorounguinol (2), 2,4-dichlorounguinol (3), and folipastatin (4), as well as one polyphenol, aspergillusphenol A (5). The major compounds, i.e., 1, 2, and 4, were tested against the ten phytopathogenic fungi. Compounds 1 and 4 were able to inhibit growth of most of the fungi, except L. theobromae, R. oryzae, and S. roflsii. Compound 1 showed the same minimum inhibitory concentration (MIC) values as that of carbendazim against A. brassicicola, C. capsici, C. oryzae, and P. oryzae, while compound 4 showed the same MIC values as that of carbendazim against only C. capsici and P. oryzae. Compound 2 was not active against all of the ten phytopathogenic fungi tested. Full article

With emerging viruses and drug resistance on the rise, the discovery and development of innovative antiviral substances and agents are necessary for the effective treatment and control of viral outbreaks. Surrogate viruses are safer alternatives used in research to mimic dangerous or hard-to-culture viruses. They enable efficient, ethical, and cost-effective screening of antiviral compounds. In this study, we used a recombinant viral hemorrhagic septicemia virus (rVHSV) expressing enhanced green fluorescent protein as a surrogate for RNA viruses for the high-throughput screening of antiviral agents. An optimized mixture of viruses and EPC host cells was distributed in 96-well plates containing chemical compounds or plant extracts for screening. Using this system, 44,642 chemical compounds and 8104 plant and marine organism extracts were tested; 140 candidates were selected from primary screening, and 8 compounds and 5 plant extracts were further selected based on the selectivity index (SI), representing the ratio of the cytotoxic concentration (CC₅₀) to the inhibition concentration (IC₅₀). Among these, compound 3, which had the highest SI value of 1046, was further tested, considering in vitro activity against VHSV and another fish rhabdovirus, snakehead rhabdovirus (SHRV). Full article

Corrosion remains a persistent and costly issue across multiple industrial domains, including infrastructure, transportation, and marine operations. The deterioration of metals and alloys under corrosive conditions results in significant financial losses and poses considerable environmental and safety risks. Although traditional corrosion inhibitors demonstrate high efficacy, they often contain toxic, synthetic compounds that endanger both human health and ecological systems. The increasing global focus on environmental responsibility and green chemistry has intensified the demand for alternative, non-toxic corrosion mitigation strategies. This review examines the use of plant extracts obtained through various processing methods as “environmentally friendly”, responsible corrosion inhibitors. This analysis underscores the capacity of plant-based compounds to counteract material degradation across diverse applications, from technologically advanced industrial systems to the preservation of cultural heritage. Through an interdisciplinary perspective, this review evaluates the viability of botanical approaches as sustainable substitutes for conventional inhibitors, contributing to a broader understanding of their potential across distinct fields. Full article

Plant growth-promoting rhizobacteria (PGPR) offer a sustainable strategy for enhancing crop productivity and suppressing phytopathogens. In this study, seven bacterial isolates obtained from the rhizosphere of healthy tomato plants were evaluated for their antagonistic activity against the fungal pathogen Passalora fulva, the leaf miner Tuta absoluta, and their effects on tomato growth. In vitro dual-culture assays revealed that isolates IQR1, IQR2, IQR3, and IQR5 significantly inhibited P. fulva mycelial growth, with inhibition rates exceeding 35%. Volatile organic compounds (VOCs) produced by the bacterial isolates exhibited considerable antifungal activity, with IQR5, IQR1, and IQR2 achieving over 84% inhibition. Molecular identification based on 16S rDNA sequencing indicated that these isolates belong to distinct taxa: Leucobacter aridicolis (ON799334.1) (genus Leucobacter), Paenochrobactrum sp. (JF804769.1) (genus Paenochrobactrum), an uncultured bacterium (JQ337400.1) (genus Psychrobacter), and marine bacterium AK6_052 (KF816539.1) (genus Brevundimonas). Under greenhouse conditions, isolates IQR3, IQR5, and IQR1 reduced disease incidence of P. fulva to 20–26%. The same isolates also promoted plant growth, enhancing stem height and collar diameter. In addition, IQR5 significantly reduced T. absoluta larval density and foliar damage, with the number of larvae per leaflet decreasing to 1.42, compared to 3.20 in the control. These findings highlight the potentials of these rhizobacterial strains—particularly IQR5—as effective biocontrol agents and biofertilizers for integrated pest and disease management in tomato cultivation. Full article

This study aimed to evaluate the effect of the continuous use of the settling chamber for solids removal in the cultivation of the marine shrimp Penaeus vannamei and the halophyte Salicornia neei in an aquaponic system with bioflocs. Two treatments were tested: with settling and without settling. Each experimental unit consisted of an 800 L tank for shrimp rearing (stocking density of 375 shrimp m⁻³) and a hydroponic bench of 0.33 m² for 28 seedlings (84 plants m⁻²). In the treatment without settling, water was continuously pumped to the hydroponic bench. In the treatment with settling, the water was first pumped to the chamber, and the overflow was then distributed across each irrigation channel, returning to the tank by gravity. To maintain the concentration of suspended solids in the shrimp culture, solids that accumulated in the settling chamber were pumped back into the tank every 30 min. During the 54-day trial, the reduction in suspended solids in the treatment with settling led to an increase in TAN and NO₂ levels, while the concentration of NO₃ remained stable. Although water quality parameters were more stable in the treatment without settling, no significant differences were observed between the treatments regarding plant and shrimp production indices. These results demonstrate the feasibility of cultivating P. vannamei and S. neei in a biofloc-based aquaponic system without the continuous use of a settling chamber during the pre-grow phase (until 10 g), offering a potential method for simplifying aquaponic system design. Full article

Emodin is an anthraquinone compound known for its diverse biological activities, including anti-tumor and anti-inflammatory effects, making it highly applicable in the fields of biology and medicine. The production of emodin using microorganisms represents a sustainable and environmentally friendly approach. A marine-derived Aspergillus flavipes HN4-13 was found to produce emodin, but the yield was too low for industrial production. To develop a high-yielding emodin-producing strain, we established the high-through detection and screening methods of alkaline coloration and deep-well plant culture, enabling the effective selection of high-yielding strains. Following ARTP mutagenesis of the wild strain A. flavipes HN4-13, the resulting mutant strain, M1440, exhibited an increased emodin yield of 124.6 ± 4.95 mg/L. Furthermore, the production of the emodin was enhanced by the exogenous addition of metal ions Mn²⁺ to the medium. Specifically, the addition of 3 mM Mn²⁺ resulted in a 133.2% increase in emodin production, with the highest yield reaching 178.6 ± 7.80 mg/L. Full article

Endophytic bacteria are an important source for developing antimicrobial substances. With the aim to find eco-friendly antimicrobial agents from natural sources, Streptomyces sp. R6 was isolated from Azadirachta indica. After that, a new spirotetronate natural product, lobophorin S (compound 2), together with lobophorin H8 (compound 1) and a known macrolide compound divergolide C (compound 3) were isolated from the cultural solution of strain R6. These compounds mark the first isolation of marine-derived microbial natural products known as lobophorins (LOBs) from endophytic bacteria. The structures of these three compounds were identified by extensive NMR and HRMS analyses. The antimicrobial activities of these three compounds against eight fungal and four bacterial phytopathogens were separately evaluated. Compound 1 demonstrated better antibacterial activity against Erwinia carotovora, Pseudomonas syringae pv. tomato, and P. syringae pv. lachrymans with MIC values of 3.91, 7.81, and 15.63 μg/mL, respectively. Additionally, compounds 1–3 all showed antifungal activity against Botrytis cinerea, with the MIC values of 1.95, 7.81, and 15.63 μg/mL, respectively. Notably, the in vivo antifungal effect of 1 against B. cinerea was up to 78.51 ± 3.80% at 1.95 µg/mL, significantly surpassing polyoxin B (70.70 ± 3.81%). These results highlight the potential of lobophorins as promising lead compounds for the development of new, sustainable agents to control plant diseases. Full article

Scaffolds resembling the extracellular matrix (ECM) provide structural support for cells in the engineering of tissue constructs. Various material sources and fabrication techniques have been employed in scaffold production. Cellulose-based matrices are of interest due to their abundant supply, hydrophilicity, mechanical strength, and biological inertness. Terrestrial and marine plants offer diverse morphologies that can replicate the ECM of various tissues and be isolated through decellularization protocols. In this study, three marine macroalgae species—namely Durvillaea poha, Ulva lactuca, and Ecklonia radiata—were selected for their morphological variation. Low-intensity, chemical treatments were developed for each species to maintain native cellulose structures within the matrices while facilitating the clearance of DNA and pigment. Scaffolds generated from each seaweed species were non-toxic for human dermal fibroblasts but only the fibrous inner layer of those derived from E. radiata supported cell attachment and maturation over the seven days of culture. These findings demonstrate the potential of E. radiata-derived cellulose scaffolds for skin tissue engineering and highlight the influence of macroalgae ECM structures on decellularization efficiency, cellulose matrix properties, and scaffold utility. Full article

This study explores the biocontrol potential of Pediococcus sp. M21F004, a lactic acid bacteria (LAB) isolated from marine environments, against several bacterial and fungal phytopathogens. Out of 50 marine bacterial isolates, Pediococcus sp. M21F004 was selected for its exceptional antimicrobial activity. The strain, isolated from the intestine of a starry flounder, was identified as Pediococcus sp. Gas chromatography–mass spectrometry (GC-MS) analysis revealed that oleic acid (OA) is a key antimicrobial compound produced by Pediococcus sp. M21F004. In vitro assays showed that the culture broth (CB) of Pediococcus sp. M21F004, as well as OA, exhibited significant inhibitory effects against pathogens such as Fusarium oxysporum, Clarireedia homoeocarpa, and Pectobacterium carotovorum subsp. carotovorum. In vivo tests on cucumber Fusarium wilt, creeping bentgrass dollar spot, tomato bacterial wilt, and kimchi cabbage soft rot further demonstrated the strain’s efficacy in reducing disease severity. Moreover, OA had the highest control value of 74% against tomato bacterial wilt, followed by 64.1% against cucumber fusarium wilt, 42.5% against kimchi cabbage soft rot, and 16.5% against creeping bentgrass dollar spot. These findings suggest that Pediococcus sp. M21F004 and its metabolite OA offer promising alternatives to chemical pesticides, contributing to sustainable plant disease management by promoting resistance induction and providing an eco-friendly approach to agriculture. Full article

Microalgae, stemming from a complex evolutionary lineage, possess a metabolic composition influenced by their evolutionary journey. They have the capacity to generate diverse polyunsaturated fatty acids (PUFAs), akin to those found in terrestrial plants and oily fish. Also, because of their numerous double bonds, these metabolic compounds are prone to oxidation processes, leading to the creation of valuable bioactive molecules called oxylipins. Moreover, owing to their adaptability across various environments, microalgae offer an intriguing avenue for biosynthesizing these compounds. Thus, modifying the culture conditions could potentially impact the profiles of oxylipins. Indeed, the accumulation of oxylipins in microalgae is subject to the influence of growth conditions, nutrient availability, and stressors, and adjusting these factors can enhance their production in microalgae culture. Consequently, the present study scrutinized the LC-MS/MS profiles of oxylipins from three marine microalgae species (two Haptagophytes and one Chlorophyte) cultivated in 1 L of photobioreactors under varying stress-inducing conditions, such as the introduction of H₂O₂, EtOAc, and NaCl, during their exponential growth phase. Approximately 50 oxylipins were identified, exhibiting different concentrations depending on the species and growth circumstances. This research suggests that microalgae metabolisms can be steered toward the production of bioactive oxylipins through modifications in the culture conditions. In this instance, the application of a low dose of hydrogen peroxide to Mi 124 appears to stimulate the production of nonenzymatic oxylipins. For Mi136, it is the application of salt stress that seems to increase the overall production of oxylipins. In the case of Mi 168, either a low concentration of H₂O₂ or a high concentration of AcOEt appears to have this effect. Full article

This article presents a comprehensive overview of recent discoveries and advancements in the field of steroid chemistry, highlighting the isolation and characterization of various steroidal compounds from natural sources. This paper discusses a wide range of steroids, including pregnane steroids, steroidal alkaloids, ketosteroids, and novel triterpenoids, derived from marine organisms, fungi, and plants. Significant findings include the isolation of bioactive compounds such as the cytotoxic erectsterates from microorganisms, soft corals, the unusual tetracyclic steroid penicillitone from a fungal culture, and innovative steroidal derivatives with potential anti-inflammatory and anticancer activities. The synthesis of steroids from microorganisms as a tool for pharmaceutical development is also explored, showcasing the role of microbial biotransformation in generating steroidal drugs. Additionally, this paper emphasizes the ecological and medicinal relevance of these compounds, which are often used in traditional medicine and have potential therapeutic applications in treating diseases like cancer and microbial infections. This article serves as a vital resource for researchers interested in the chemical diversity of steroids and their applications in drug discovery and development. Full article

Epitranscriptomics is considered as a new regulatory step in eukaryotes for developmental processes and stress responses. The aim of this study was, for the first time, to identify RNA methyltransferase (writers) and demethylase (erasers) in four investigated species, i.e., the dinoflagellates Alexandrium tamutum and Amphidinium carterae, the diatom Cylindrotheca closterium, and the green alga Tetraselmis suecica. As query sequences for the enzymatic classes of interest, we selected those ones that were previously detected in marine plants, evaluating their expression upon nutrient starvation stress exposure. The hypothesis was that upon stress exposure, the activation/deactivation of specific writers and erasers may occur. In microalgae, we found almost all plant writers and erasers (ALKBH9B, ALKBH10B, MTB, and FIP37), except for three writers (MTA, VIRILIZER, and HAKAI). A sequence similarity search by scanning the corresponding genomes confirmed their presence. Thus, we concluded that the three writer sequences were lacking from the studied transcriptomes probably because they were not expressed in those experimental conditions, rather than a real lack of these genes from their genomes. This study showed that some of them were expressed only in specific culturing conditions. We also investigated their expression in other culturing conditions (i.e., nitrogen depletion, phosphate depletion, and Zinc addition at two different concentrations) in A. carterae, giving new insights into their possible roles in regulating gene expression upon stress. Full article

Marine microorganisms have evolved special metabolic pathways to produce numerous bioactive substances with novel structures and unique functions. This study analyzed the diversity of culturable bacteria in marine water samples from the South China Sea and screened the isolated bacteria with pathogenic fungi. A total of 200 culturable strains of 72 different bacteria were obtained from 56 water samples from the South China Sea. They belonged to three phyla and four classes, namely Gammaproteobacteria, Alphaproteobacteria, Bacilli and Actinomycetia. Bacilli was the dominant class, comprising up to 59.72%, followed by Gammaproteobacteria (20.83%). Bacillus, Pseudomonas, Paenibacillus and Rhizobium were the most dominant genera. Among these strains, HY-88 and HY-91 encoding BamC, FenB and PKSI genes were selected and identified as Bacillus subtilis. The respective inhibition rates of the HY-88 caused by plate confrontation against Magnaporthe grisea, Fusarium oxysporum, Botrytis cinerea, anthrax and Botrytis cinerea were 90.91%, 54.29%, 52.17% and 51.72%, in comparison with HY-91 86.36%, 48.57%, 47.83% and 34.48%. In addition, the supernatant of HY-88 showed a lesion inhibition rate of 74.5%, which was significantly higher than HY-91 (60.55%). In addition, HY-88 and HY-91 showed strong antifungal activity to Colletotrichum viniferum on detached Shine Muscat grapes. Tolerance tests showed that the HY-88 and HY-91 grew at 10–40 °C, 7–10% NaCl and pH 3-11. HY-88 and HY-91 could inhibit various fungal plant diseases, which lays a foundation for the development of new biopesticides. Full article

Precise delineation of marine aquaculture areas is vital for the monitoring and protection of marine resources. However, due to the coexistence of diverse marine aquaculture areas and complex marine environments, it is still difficult to accurately delineate mariculture areas from very high spatial resolution (VHSR) images. To solve such a problem, we built a novel Transformer–CNN hybrid Network, named TCNet, which combined the advantages of CNN for modeling local features and Transformer for capturing long-range dependencies. Specifically, the proposed TCNet first employed a CNN-based encoder to extract high-dimensional feature maps from input images. Then, a hierarchical lightweight Transformer module was proposed to extract the global semantic information. Finally, it employed a coarser-to-finer strategy to progressively recover and refine the classification results. The results demonstrate the effectiveness of TCNet in accurately delineating different types of mariculture areas, with an IoU value of 90.9%. Compared with other state-of-the-art CNN or Transformer-based methods, TCNet showed significant improvement both visually and quantitatively. Our methods make a significant contribution to the development of precision agricultural in coastal regions. Full article

Brown algae from genus Cystoseira s.l. form dense underwater forests that represent the most productive areas in the Mediterranean Sea. Due to the combined effects of global and local stressors such as climate change, urbanization, and herbivore outbreaks, there has been a severe decline in brown algal forests in the Mediterranean Sea. Natural recovery of depleted sites is unlikely due to the low dispersal capacity of these species, and efficient techniques to restore such habitats are needed. In this context, the aims of our study were (1) to improve and simplify the current ex situ laboratory protocol for the cultivation of Gongolaria barbata by testing the feasibility of some cost-effective and time-efficient techniques on two donor sites of G. barbata and (2) to evaluate the survival and growth of young thalli during the laboratory phase and during the most critical five months after out-planting. Specifically, the following ex situ cultivation methods were tested: (A) cultivation on clay tiles in mesocosms with culture water prepared by three different procedures (a) filtered seawater with a 0.22 μm filter membrane, (b) filtered seawater with a 0.7 μm filter membrane (GF), and (c) UV-sterilized water, and (B) cultivation on clay tiles in open laboratory systems. After two weeks, all thalli were fixed to plastic lantern net baskets suspended at a depth of 2 m in the coastal sea (hybrid method), and the algal success was monitored in relation to the different donor sites and cultivation protocol. The satisfactory results of this study indicate that UV-sterilized water is suitable for the cultivation of G. barbata in mesocosm, which significantly reduces the cost of the laboratory phase. This opens the possibility of numerous and frequent algal cultures during the reproductive period of the species. Additionally, if the young thalli remain in the lantern net baskets for an extended period of several months, they can grow significantly in the marine environment without being exposed to pressure from herbivorous fish. Full article