Search Results (28)

In order to promote the development of biodiversity, the present study conducted three sampling surveys at 26 representative sampling sites selected from the Chishui River, a freshwater river in China, in July (rainy season), November (flat water period), and April 2024 (dry season), respectively, focusing on the relationship between benthic algae and the response of water environmental factors. The results revealed that a total of 140 species from 48 genera and 7 phyla of benthic algae were identified, with the highest number of species belonging to the diatom phylum (85 species). The average density of benthic algae was highest during the flat water period, followed by the dry season and the flood season. Microcystis sp. was the dominant species during the flood season, while Gomphonema sp., Achnanthes tumescens, and Oscillatoria sp. were common dominant species during the dry and flat water periods. Achnanthes tumescens was the absolute dominant species in the upstream during the dry and flat water periods; Leptolyngbya sp. was the absolute dominant species in the midstream during the flat water period, and Oscillatoria sp. was the absolute dominant species in the middle reaches during the dry season. The Shannon-Wiener index, Margalef index, and species richness of benthic algae during the dry and flat water periods decreased from upstream to downstream. Non-metric multidimensional scaling analysis revealed significant differences in the community structures of benthic algae in the upper, middle, and downstream areas of the Chishui River during different periods, while cluster analysis indicated high similarity among benthic algae communities in locally adjacent areas. The differences in the benthic algae community structure increased with environmental and geographical distance, with environmental distance playing a greater role than geographical distance. RDA (Redundancy Analysis) identified TN (Total Nitrogen), TP (Total Phosphorus), DO (Dissolved Oxygen), EC (Electrical Conductivity), and NH₃-N (Ammonia Nitrogen) as key water environmental factors influencing the structure of benthic algal communities in the Chishui River. Full article

Cyanobacteria are among the oldest organisms colonizing Earth. Their great biodiversity and ability to biosynthesize secondary metabolites through a variety of routes makes them attractive resources for biotechnological applications and drug discovery. In this pioneer study, four filamentous cyanobacteria (Cephalothrix lacustris LEGE 15493, Leptolyngbya boryana LEGE 15486, Nodosilinea nodulosa LEGE 06104 and Leptothoe sp. LEGE 11479) were explored for their anti-inflammatory potential in cell and cell-free in vitro bioassays, involving different inflammatory mediators and enzymes. Extracts of different polarities were sequentially prepared and chemically characterized for their content of phycobiliproteins (PBPs) and carotenoids. HPLC-PDA analysis of the acetone extracts revealed β-carotene to be the dominant carotenoid (18.4–44.3 mg/g) and zeaxanthin as the dominant xanthophyll (52.7–192.9 mg/g), with Leptothoe sp. LEGE 11479 and Nodosilinea nodulosa LEGE 06104, respectively, being the richest strains. The PBP profile was in accordance with the color presented by the aqueous extracts, with Leptolyngbya boryana LEGE 15486 being the richest in phycocyanin (204.5 μg/mg) and Leptothoe sp. LEGE 11479 the richest in phycoerythrin (78.5 μg/mg). Aqueous extracts were more effective in superoxide anion radical scavenging, while acetone ones were more effective in scavenging nitric oxide radical (^●NO) and in inhibiting lipoxygenase. Acetone extracts also reduced ^●NO production in lipopolysaccharide-stimulated RAW 264.7 macrophages, with the mechanistic study suggesting a downregulation of the inducible nitric oxide synthase expression. Nodosilinea nodulosa LEGE 06104 and Leptothoe sp. LEGE 11479 acetone extracts presented the lowest IC₅₀ values for the mentioned assays, pointing them out as promising resources for the development of new multi-target anti-inflammatory therapies. Full article

During the study of diversity in filamentous cyanobacteria in China, two strains (WZU0719 and WZU0723) with the form of thin filaments were isolated from the surface of Qiandao Lake, a large freshwater lake in Zhejiang Province, China. A comprehensive analysis was conducted, incorporating morphological, ecological, and molecular data. The morphological examination provided an initial identification as a Leptolyngbya-like cyanobacterium. Genetic characterization was also performed by amplifying the 16S rRNA gene and the 16S-23S rRNA internal transcribed spacer (ITS) region. The phylogenetic grouping based on the 16S rRNA gene demonstrates that the examined strain is unequivocally assigned to the Pegethrix genus. However, it possesses distinct phylogenetic divergence from the six described Pegethrix species. Additionally, discrepancies in habitat further differentiate it from other members of this genus. Employing the polyphasic approach, we present a comprehensive account of the newly discovered taxa: Pegethrix qiandaoensis sp. nov. The novel taxonomic finding in this research significantly contributes to enhancing the comprehension of Pegethrix diversity across various habitats. Full article

The study explores the application of natural biocides (oregano essential oil and eugenol, directly applied in solutions or encapsulated within silica nanocapsules) for safeguarding stone cultural heritage from biodeterioration, using green algae (Chlorococcum sp.) and cyanobacteria (Leptolyngbya sp.) as common pioneer biodeteriogens. Core-shell nanocontainers were built for a controlled release of microbicidal agents, a safe application of chemicals and a prolonged efficacy. The qualitative and quantitative evaluations of biocide efficiency at different doses were periodically performed in vitro, after six scheduled intervals of time (until 100 days). The release kinetics of composite biocide-embedding silica nanocapsules were characterized by the UV-Vis spectroscopy technique. Data showed both promising potential and some limitations. The comparative tests of different biocidal systems shed light on their variable efficacy against microorganisms, highlighting how encapsulation influences the release dynamics and the overall effectiveness. Both the essential oils showed a potential efficacy in protective antifouling coatings for stone artifacts. Ensuring compatibility with materials, understanding their differences in biocidal activity and their release rates becomes essential in tailoring gel, microemulsion or coating products for direct on-site application. Full article

The importance of lung microbiome changes in developing chronic lung allograft dysfunction (CLAD) after lung transplantation is poorly understood. The lung microbiome–immune interaction may be critical in developing CLAD. In this context, examining alterations in the microbiome and immune cells of the lungs following CLAD, in comparison to the lung condition immediately after transplantation, can offer valuable insights. Four adult patients who underwent lung retransplantation between January 2019 and June 2020 were included in this study. Lung tissues were collected from the same four individuals at two different time points: at the time of the first transplant and at the time of the explantation of CLAD lungs at retransplantation due to CLAD. We analyzed whole-genome sequencing using the Kraken2 algorithm and quantified the cell fractionation from the bulk tissue gene expression profile for each lung tissue. Finally, we compared the differences in lung microbiome and immune cells between the lung tissues of these two time points. The median age of the recipients was 57 years, and most (75%) had undergone lung transplants for idiopathic pulmonary fibrosis. All patients were administered basiliximab for induction therapy and were maintained on three immunosuppressants. The median CLAD-free survival term was 693.5 days, and the median time to redo the lung transplant was 843.5 days. Bacterial diversity was significantly lower in the CLAD lungs than at transplantation. Bacterial diversity tended to decrease according to the severity of the CLAD. Aerococcus, Caldiericum, Croceibacter, Leptolyngbya, and Pulveribacter genera were uniquely identified in CLAD, whereas no taxa were identified in lungs at transplantation. In particular, six taxa, including Croceibacter atlanticus, Caldiserium exile, Dolichospermum compactum, Stappia sp. ES.058, Kinetoplastibacterium sorsogonicusi, and Pulveribacter suum were uniquely detected in CLAD. Among immune cells, CD8+ T cells were significantly increased, while neutrophils were decreased in the CLAD lung. In conclusion, unique changes in lung microbiome and immune cell composition were confirmed in lung tissue after CLAD compared to at transplantation. Full article

Leptolyngbya sp. KIOST-1 has been proposed as a candidate species for use as a protein supplement due to its high protein content and absence of cytotoxicity. The species has also garnered attention due to the photosynthetic pigments it possesses. However, limited information is available on its cultivation. Therefore, this study was conducted to identify the optimal culture medium and fundamental physiological properties of Leptolyngbya sp. KIOST-1 under various culture conditions. In this study, SOT (Society of Toxicology) medium was confirmed as the optimal culture medium for Leptolyngbya sp. KIOST-1 growth. The biomass production, protein content, and photosynthetic pigment content of Leptolyngbya sp. KIOST-1 were significantly higher in SOT medium. The use of this medium allowed for scaling up from laboratory (10 mL) to pilot (200 L) conditions and industrial-scale outdoor conditions (10,000 L), with the biomass containing over 66% protein. The phytochemical composition of Leptolyngbya sp. KIOST-1 cultured at laboratory and industrial-scales was discovered in this study. Furthermore, we observed that reducing the carbon and nitrogen sources to 1/5 of those supplied by the optimal medium did not significantly affect biomass production, and Leptolyngbya sp. KIOST-1 demonstrated favorable growth capabilities in a salinity range of 10–50 psu and at pH levels of 8.3 to 10.3. The results of this study demonstrate the suitability of Leptolyngbya sp. KIOST-1 for various industrial applications and its adaptability to large-scale cultivation. Full article

The incidence of diseases brought on by resistant strains of micro-organisms, including tuberculosis, is rising globally as a result of the rapid rise in pathogenic micro-organism resistance to antimicrobial treatments. Secondary metabolites with potential for antibacterial activity are produced by cyanobacteria and microalgae. In this study, gram-positive (S. aureus, E. faecalis) and gram-negative (K. pneumoniae, A. baumannii, P. aeruginosa) bacteria were isolated from pulmonary tuberculosis patients receiving long-term antituberculosis therapy. The antimicrobial potential of extracts from the cyanobacteria Leptolyngbya cf. ectocarpi, Planktothrix agardhii, Arthrospira platensis, Rohotiella mixta sp. nov., Nanofrustulum shiloi, and Tetraselmis (Platymonas) viridis Rouchijajnen was evaluated. On mouse splenocytes and peritoneal macrophages, extracts of cyanobacteria and microalgae had inhibitory effects. In vitro studies have shown that cyanobacteria and microalgae extracts suppress the growth of bacteria and mycobacteria. At the same time, it has been demonstrated that cyanobacterial and microalgal extracts can encourage bacterial growth in a test tube. Additionally, the enhanced fucoxanthin fraction significantly reduced the development of bacteria in vitro. In a mouse experiment to simulate tuberculosis, the mycobacterial load in internal organs was considerably decreased by fucoxanthin. According to the information gathered, cyanobacteria and microalgae are potential sources of antibacterial compounds that can be used in the manufacturing of pharmaceutical raw materials. Full article

Cyanobacteria are ever-present, mainly flourishing in aquatic environments and surviving virtually in other habitats. The microbiota of indoor dust on the pre-filter of heating, ventilation, and air-conditioning (HVAC) systems, which reflect indoor microbial contamination and affect human health, has attracted attention. Contemporary studies on cyanobacteria deposited on the pre-filter of HVAC remain scant. By the culture-independent approach of qPCR and high throughput sequencing technologies, our results documented that the cyanobacterial concentrations were highest in autumn, occurred recurrently, and were about 2.60 and 10.57-fold higher than those in winter and summer. We proposed that aquatic and terrestrial cyanobacteria contributed to the pre-filter of HVAC by airborne transportation produced by wave breaks, bubble bursts, and soil surface by wind force, owing to the evidence that cyanobacteria were commonly detected in airborne particulate matters. The cyanobacteria community structure was characterized in Shanghai, where Chroococcidiopsaceae, norank_cyanobacteriales, Nostocaceae, Paraspirulinaceae, and others dominated the dust on the pre-filter of HVAC. Some detected genera, including Nodularia sp., Pseudanabaena sp., and Leptolyngbya sp., potentially produced cyanobacterial toxins, which need further studying to determine their potential threat to human health. The present work shed new insight into cyanobacteria distribution in the specific environment besides aquatic habitats. Full article

Metallic nanoparticles have received a significant amount of reflection over a period of time, attributed to their electronic, specific surface area, and surface atom properties. The biogenic synthesis of iron oxide nanoparticles (FeONPs) is demonstrated in this study. The green synthesis of metallic nanoparticles (NPs) is acquiring considerable attention due to its environmental and economic superiorities over other methods. Leptolyngbya sp. L-2 extract was employed as a reducing agent, and iron chloride hexahydrate (FeCl₃·6H₂O) was used as a substrate for the biogenic synthesis of FeONPs. Different spectral methods were used for the characterization of the biosynthesized FeONPs, ultraviolet-visible (UV-Vis) spectroscopy gave a surface plasmon resonance (SPR) peak of FeONPs at 300 nm; Fourier transform infrared (FTIR) spectral analysis was conducted to identify the functional groups responsible for both the stability and synthesis of FeONPs. The morphology of the FeONPs was investigated using scanning electron microscopy (SEM), which shows a nearly spherical shape, and an X-ray diffraction (XRD) study demonstrated their crystalline nature with a calculated crystallinity size of 23 nm. The zeta potential (ZP) and dynamic light scattering (DLS) measurements of FeONPs revealed values of −8.50 mV, suggesting appropriate physical stability. Comprehensive in-vitro pharmacogenetic properties revealed that FeONPs have significant therapeutic potential. FeONPs have been reported to have potential antibacterial and antifungal properties. Dose-dependent cytotoxic activity was shown against Leishmania tropica promastigotes (IC50: 10.73 µg/mL) and amastigotes (IC50: 16.98 µg/mL) using various concentrations of FeONPs. The cytotoxic potential was also investigated using brine shrimps, and their IC50 value was determined to be 34.19 µg/mL. FeONPs showed significant antioxidant results (DPPH: 54.7%, TRP: 49.2%, TAC: 44.5%), protein kinase (IC50: 96.23 µg/mL), and alpha amylase (IC50: 3745 µg/mL). The biosafety of FeONPs was validated by biocompatibility tests using macrophages (IC50: 918.1 µg/mL) and red blood cells (IC50: 2921 µg/mL). In conclusion, biogenic FeONPs have shown potential biomedical properties and should be the focus of more studies to increase their nano-pharmacological significance for biological applications. Full article

The present study evaluated 53 Irish marine cyanobacteria intending to identify potential producers of mycosporine-like amino acids (MAAs) to meet the increasing demand for replacing chemical sunscreen with bio-sunscreen. The biodiscovery analysis using absorption spectra of methanolic extracts identified eight cyanobacteria as potential MAAs producers with a specific content of 0.114–0.511 A* mg DW⁻¹. Leptolyngbya tenuis SABC010201 was found to possess notably higher MAAs content. LC-MS analysis identified a total of eight different types of known MAAs (mycosporine-glutamicol, mycosporine-glutaminol-glucoside, mycosporine-serinol, mycosporine-taurine, palythine, palythine-threonine-sulphate, porphyra-334, and usujirene) in eight cyanobacteria, while four compounds were considered unknown UV-absorbing compounds with specific mass and absorption maximum. For example, two unknown compounds with, respectively, [M-H]^- values of 219.0557 and 289.0730 and lambda max of 314 and 326 nm, were detected in three cyanobacteria Leptolyngbya tenuis SABC010201, Phormidium angustissimum SABC020801, and Schizothrix sp. SABC022401. These two unknown compounds were named M-314 and M-326, respectively. Antioxidant activities of total MAAs of all cyanobacteria showed considerable amounts of DPPH, FRAP, and ORAC activities. Considering the specific MAAs content and antioxidant activities, Leptolyngbya africana SABC021601 was considered the best producer of MAAs. Full article

Unique natural objects, such as the caves of the Gobustan National Historical and Artistic Preserve, are also of great cultural and historical value due to rock art and sites of ancient people. A favorable microclimate makes these habitats convenient for colonization by microbiota, including phototrophs. In arid regions with intense seasonal fluctuations of microclimatic parameters, the conditions for survival are the least favorable; therefore, it becomes especially important to determine the composition of communities that are the most adapted to specific conditions. This work aimed to identify the biodiversity of communities of caves and grottoes of the Gobustan Reserve. The studies were carried out in July 2019. Samples were analyzed for cyanobacteria and algae by microscopy and cultivation methods, microfungi were isolated by soil dilution, and the fouling glass method was also used. In total, 29 taxa of cyanobacteria and algae, 18 taxa of fungi, and 3 species of mosses were identified. The studied habitats were dominated by the algae Chlorella vulgaris, Aphanocapsa sp., and Stichococcus bacillaris; the subdominants were Jaaginema subtilissimum, Leptolyngbya tenuis, Chlorococcum minutum, and Humidophila contenta. Microfungi had the highest occurrence of Aspergillus niger, Aureobasidium pullulans, Alternaria alternata, and Talaromyces ruber. It was noted that cyanobacteria dominated in morphologically differentiated biofilms and green algae on the rocks. The greatest number of microfungi was found in the aphotic zone and bryophyte tufts. The dominance of green algae is atypical for most caves of other regions and may be associated with intense lighting of habitats. The absence of protonema is a consequence of the aridity and low moisture content of the substrates. Full article

Cyanobacteria are rich in phytochemicals, which have beneficial impacts on the prevention of many diseases. This study aimed to comprehensively characterize phytochemicals and evaluate multifunctional bioactivities in the ethanolic extract of the cyanobacterium Leptolyngbya sp. KC45. Results found that the extract mainly contained chlorophylls, carotenoids, phenolics, and flavonoids. Through LC–ESI–QTOF–MS/MS analysis, 38 phenolic compounds with promising bioactivities were discovered, and a higher diversity of flavonoids was found among the phenolic compounds identified. The extract effectively absorbed the harmful UV rays and showed high antioxidant activity on DPPH, ABTS, and PFRAP. The extract yielded high-efficiency inhibitory effects on enzymes (tyrosinase, collagenase, ACE, and α-glucosidase) related to diseases. Interestingly, the extract showed a strong cytotoxic effect on cancer cells (skin A375, lung A549, and colon Caco-2), but had a much smaller effect on normal cells, indicating a satisfactory level of safety for the extract. More importantly, the combination of the DNA ladder assay and the TUNEL assay proved the appearance of DNA fragmentation in cancer cells after a 48 h treatment with the extract, confirming the apoptosis mechanisms. Our findings suggest that cyanobacterium extract could be potentially used as a functional ingredient for various industrial applications in foods, cosmetics, pharmaceuticals, and nutraceuticals. Full article

Staphylococcus aureus (SA) and Methicillin-resistant Staphylococcus aureus (MRSA) are multidrug-resistant bacterial pathogens. A novel approach needs to be followed to combat these pathogens in an ecofriendly manner. Cyanobacterial extracts were previously proven to be affective as antimicrobial agents. To capitalize on this, laser treatments were used to increase their antimicrobial efficacy. Two cyanobacterial strains isolated from Al-Ahsa were identified using molecular methods. Their aqueous extracts were used in the antimicrobial bioassay for these two bacterial pathogens. The first group of aqueous extracts were exposed directly to laser treatment and used in antibacterial bioassay. In parallel, the cyanobacterial biomass of the two isolates was exposed to the laser, then aqueous extracts were prepared. The third group of extracts were not exposed to the laser and were used as a control. Time and distance were the factors tested as they affected the dose of the laser, both individually and in combination. In addition, accessory pigment estimation in extracts before and after laser exposure of extracts was also determined. The two cyanobacterial strains were identified as Thermoleptolyngbya sp. and Leptolyngbya sp. and the molecular analysis also confirmed the identity of pathogenic bacteria. The untreated cyanobacterial aqueous extracts had little effect against the two bacterial strains. In contrast, the extract directly exposed to the laser was significantly more effective, with an inhibition zone of 22.0 mm in the case of a time of 32 min and distance of 10 cm against S. aureus. Accessory pigment composition increased in extracts directly exposed to the laser. This is the first case report on the effect of lasers on enhancing the antimicrobial profile of cyanobacterial extracts against SA and MRSA bacterial pathogens, as well as enhancing accessory pigment content. The laser dose that was most effective was that of 32 min time and 10 cm distance of Thermoleptolyngbya sp. extract directly exposed to the laser, which highlights the importance of time for increasing the laser dose and consequently increasing its antimicrobial impact. Full article

Cyanobacteria are considered a rich source of secondary metabolites with potential biotechnological applications. Additionally, they have the capability to produce some potent toxins (cyanotoxins) that can have consequences for both environmental and human health. This group of microorganisms with a long evolutionary history and a remarkable adaptability can be found both in aquatic and terrestrial ecosystems, including extreme environments (e.g., freshwater, marine, terrestrial, hot springs, deserts, etc.). Cyanotoxins can be classified into five functional groups according to their primary target organ or effects being designated as hepatotoxins, neurotoxins, cytotoxins, dermatotoxins, and irritant toxins. In this work, the presence of genes involved in the biosynthesis of cyanotoxins (microcystin, saxitoxin, cylindrospermopsin, and anatoxin) were screened from more than 200 strains of cyanobacteria. The isolates were obtained from different samples along the Moroccan Atlantic coast (several sampling sites from El Jadida to Essaouira), and from an ancient Portuguese cistern located at El Jadida. There is a gap in the literature regarding the presence of cyanotoxins in this region and some of the isolated strains are related to genera (e.g., Phormidium sp., Pseudanabaena sp., Leptolyngbya sp., Lyngbya sp., and Geitlerinema sp.) that have been reported as potential cyanotoxins producers. Future work will include detection by liquid chromatography–mass spectrometry (LC-MS) to confirm the production of cyanotoxins. Furthermore, the isolates will be deposited in our in-house culture collection (LEGE-CC), and will be available for future studies, increasing the size and diversity of the collection. Full article

The effect of laser radiation has never been tested on the antimicrobial activity of cyanobacterial extracts. In order to investigate this, aqueous extracts from three cyanobacterial strains identified as Thermoleptolyngbya sp., Leptolyngbya sp., and Synechococcus elongatus were exposed to laser radiation. The aqueous extracts both directly exposed to the laser and those derived from pre-exposed biomass were tested for their antimicrobial activity to select the most active extracts under different exposure times and distances from the laser source. Methods: A fixed weight of one-month old cyanobacterial biomass was used in extraction. Another similar biomass was exposed to laser before aqueous extraction. The laser treatment was performed using two distances, 5 and 10 cm, with three exposure times, 4, 16, and 32 min. The antimicrobial assay was performed against the bacterial plant pathogen, whose identity was confirmed by molecular analysis and cell wall structure by a Gram stain. Results: The pathogenic bacterium was identified as Gram-negative Pantoae vagans. The aqueous extract that was not exposed to laser treatment (control) was mostly ineffective against the pathogenic bacterium, whereas a significant increase in the antimicrobial effect was observed for the extract directly exposed to the laser followed by the extract derived from laser-pre-exposed cyanobacterial biomass. In the case of Synechococcus elongatus extracts, the extract that was directly exposed to the laser showed the highest statistically significant antimicrobial activity against Pantoea vagans, with an inhibition zone of 15.5 mm, at 10 cm and 4 min of laser treatment. Conclusions: This is the first report on the effect of laser on enhancing the antimicrobial profile of cyanobacterial extracts. The direct exposure of cyanobacterial extracts to the laser was more effective and biologically safer than exposing the biomass itself prior to extraction. The laser used was a monochromatic red light within the visible range. This radiation increased the antimicrobial activity of cyanobacterial extracts and can be used as an eco-friendly biocontrol strategy. Full article