Cyanobacteria

Cyanobacteria, red algae, and cryptophytes produce two classes of proteins for light-harvesting: water-soluble phycobiliproteins and membrane-intrinsic proteins that bind chlorophylls and carotenoids. In cyanobacteria, red algae, and glaucophytes, phycobilisomes (PBS) are complexes of brightly colored phycobiliproteins and linker (assembly) proteins. To date, six structural classes of phycobilisomes have been described: hemiellipsoidal, block-shaped, hemidiscoidal, bundle-shaped, paddle-shaped, and far-red-light bicylindrical...

The inoculation of cyanobacteria for enriching soil nutrients and forming biological soil crusts (BSCs) is considered an effective means to restore degraded soil. However, there are limited studies on the application of co-inoculation of fungi and cyanobacteria for degraded soil remediation. In this study, a high exopolysaccharide-secreting fungi Zh2 was isolated from lichen BSCs in Hobq Desert, and co-inoculated with a cyanobacterial strain identified as Phormidium tenue in different proportions to form BSCs on sand during a 35 days incubation period...

BACKGROUND: Cutaneous melanoma (CM) of the skin stands as the leading cause of mortality among skin cancer-related deaths. Despite the successes achieved with novel therapies such as immunotherapy and targeted therapy, their efficacy remains limited, necessitating further exploration of new treatment modalities. The gut microbiota and CM may be linked, as indicated by a growing body of preclinical and observational research. Nevertheless, the exact correlation between the intestinal microbiota and CM remains to be determined...

Cyanobacteria have been proposed as a potential alternative carbohydrate feedstock and multiple species have been successfully engineered to secrete fermentable sugars. To date, the most productive cyanobacterial strains are those designed to secrete sucrose, yet there exist considerable differences in reported productivities across different model species and laboratories. In this study, we investigate how cultivation conditions (specifically, irradiance, CO2 , and cultivator type) affect the productivity of sucrose-secreting Synechococcus elongatus PCC 7942...

UNLABELLED: Tail fat deposition of Altay sheep not only increased the cost of feeding but also reduced the economic value of meat. Currently, because artificial tail removal and gene modification methods cannot solve this problem, it is maybe to consider reducing tail fat deposition from the path of intestinal microbiota and metabolite. We measured body weight and tail fat weight, collected the serum for hormone detection by enzyme-linked immunosorbent assay, and collected colon contents to 16S rRNA sequence and liquid chromotography with mass spectrometry detection to obtain colon microbiota and metabolite information, from 12 3-month-old and 6-month-old Altay sheep...

The sulfolipid sulfoquinovosyl diacylglycerol (SQDG), produced by plants, algae, and cyanobacteria, constitutes a major sulfur reserve in the biosphere. Microbial breakdown of SQDG is critical for the biological utilization of its sulfur. This commences through release of the parent sugar, sulfoquinovose (SQ), catalyzed by sulfoquinovosidases (SQases). These vanguard enzymes are encoded in gene clusters that code for diverse SQ catabolic pathways. To identify, visualize and isolate glycoside hydrolase CAZY-family 31 (GH31) SQases in complex biological environments, we introduce SQ cyclophellitol-aziridine activity-based probes (ABPs)...

The problem of soil barrier caused by excessive accumulation of nitrogen is common in continuous cropping soil of facility agriculture. To investigate the modulating effects of biochar amendment on soil nitrogen transformation in greenhouse continuous cropping systems, we conducted a pot experiment with two treatments, no biochar addition (CK) and 5% biochar addition (mass ratio). We analyzed the effects of biochar addition on soil microbial community structure, abundances of genes functioning in nitrogen cycling, root growth and nitrogen metabolism-related genes expressions of cucumber seedlings...

The overuse of chemical-based agricultural inputs has led to the degradation of soil with associated adverse effects on soil attributes and microbial population. This scenario leads to poor soil health and is reportedly on the rise globally. Additionally, chemical fertilizers pose serious risks to the ecosystem and human health. In this study, foliar sprays of biostimulant (AgroGain/LBS6) prepared from the cultivated, tropical red seaweed Kappaphycus alvarezii increased the phenotypic growth of Zea mays in terms of greater leaf area, total plant height, and shoot fresh and dry weights...

The increase in global population and industrial development has led to a significant release of organic and inorganic pollutants into water streams, threatening human health and ecosystems. Microalgae, encompassing eukaryotic protists and prokaryotic cyanobacteria, have emerged as a sustainable and cost-effective solution for removing these pollutants and mitigating carbon emissions. Various microalgae species, such as C. vulgaris, P. tricornutum, N. oceanica, A. platensis, and C. reinhardtii, have demonstrated their ability to eliminate heavy metals, salinity, plastics, and pesticides...

Secondary metabolites produced by primary producers have a wide range of functions as well as indirect effects outside the scope of their direct target. Research suggests that protease inhibitors produced by cyanobacteria influence grazing by herbivores and may also protect against parasites of cyanobacteria. In this study, we asked whether those same protease inhibitors produced by cyanobacteria could also influence the interactions of herbivores with their parasites. We used the Daphnia - Metschnikowia zooplankton host-fungal parasite system to address this question because it is well documented that cyanobacteria protease inhibitors suppress trypsin and chymotrypsin in the gut of Daphnia , and because it is known that Metschnikowia infects via the gut...

Cyanobacteria, a group of microalgae are the potent organism having the ability to survive in the copper rich environment and recently gained too much attention for their profuse proliferation in such water bodies. Amongst the members of cyanobacteria, the current study was conducted on Leptolyngbya sp. GUEco1015, collected from hydrocarbon rich water bodies of Assam, India. Morphological images of treated samples showed a remarkable damage in the cell surface as well as the organelles over the control. Biochemical results revealed a significant increase of enzymatic and non-enzymatic antioxidants during oxidative damage of Cu2+ ...

Biocrusts, common in natural ecosystems, are specific assemblages of microorganisms at or on the soil surface with associated microorganisms extending into the top centimeter of soil. Agroecosystem biocrusts have similar rates of nitrogen (N) fixation as those in natural ecosystems, but it is unclear how agricultural management influences their composition and function. This study examined the total bacterial and diazotrophic communities of biocrusts in a citrus orchard and a vineyard that shared similar climate and soil type but differed in management...

Many organisms have formed symbiotic relationships with nitrogen (N)-fixing bacteria to overcome N limitation. Diatoms in the family Rhopalodiaceae host unicellular, N-fixing cyanobacterial endosymbionts called spheroid bodies (SBs). Although this relationship is relatively young, SBs share many key features with older endosymbionts, including coordinated cell division and genome reduction. Unlike free-living relatives that fix N exclusively at night, SBs fix N largely during the day; however, how SB metabolism is regulated and coordinated with the host is not yet understood...

OBJECTIVES: Contamination of surface waters is a major health threat for all living creatures. Some types of blue-green algae that naturally occur in fresh water, are able to produce various toxins, like Microcystins (MCs). Microcystin-leucine arginine (MC-LR) produced by Microcystis aeruginosa is the most toxic and abundant isoforms of MCs, and it causes hepatotoxicity. The present article reviews preclinical experiments examined different treatments, including herbal derivatives, dietary supplements and drugs against MC-LR hepatotoxicity...

Tetrodotoxin (TTX) is a potent neurotoxin causing human intoxications from contaminated seafood worldwide and is of emerging concern in Europe. Shellfish have been shown to contain varying TTX concentrations globally, with concentrations typically higher in Pacific oysters Crassostrea gigas in Europe. Despite many decades of research, the source of TTX remains unknown, with bacterial or algal origins having been suggested. The aim of this study was to identify potential source organisms causing TTX contamination in Pacific oysters in French coastal waters, using three different techniques...

The present study demonstrates the presence of the neurotoxin β-N-methylamino-L-alanine and its cyanobacterial producers in irrigation water and grains of some cereal plants from farmlands irrigated with Nile River water in Egypt. BMAA detected by LC-MS/MS in phytoplankton samples was found at higher concentrations of free form (0.84-11.4 μg L-1 ) than of protein-bound form (0.16-1.6 μg L-1 ), in association with the dominance of cyanobacteria in irrigation water canals. Dominant cyanobacterial species isolated from these irrigation waters including Aphanocapsa planctonica, Chroococcus minutus, Dolichospermum lemmermanni, Nostoc commune, and Oscillatoria tenuis were found to produce different concentrations of free (4...

Fluctuations in dissolved oxygen (DO) contents in natural waters can become intense during cyanobacteria blooms. In a reconnaissance study, we investigated DO concentrations and stable isotope dynamics during a laboratory experiment with the cyanobacterium Planktothrix rubescens in order to obtain insights into primary production under specific conditions. This observation was extended to sub-daily timescales with alternating light and dark phases. Dissolved oxygen concentrations and its isotopes (δ18 ODO ) ranged from 0...

Surface display technologies have been primarily developed for heterotrophic microbes, leaving photosynthetic counterparts like cyanobacteria with limited molecular tools. Here, we expanded upon surface display systems in Synechococcus elongatus PCC 7942 by modifying two outer-membrane proteins, SomA and Intimin, to display tags ( e.g. , SpyTag) to mediate physical interactions of living cyanobacteria with other biotic and abiotic targets. While re-engineered SomA constructs successfully translocated to the cell surface and could bind to compatible ligands, the efficacy of the best-performing designs was limited by a poorly-understood heterogeneity in the accessibility of the tags in living cells, resulting in low attachment penetrance...

Chronic pain is a complex disease. It seriously affects patients' quality of life and imposes a significant economic burden on society. Santacruzamate A (SCA) is a natural product isolated from marine cyanobacteria in Panama. In this study, we first demonstrated that SCA could alleviate chronic inflammatory pain, pain-related anxiety, and depression emotions induced by complete Freund's adjuvant in mice while inhibiting microglial activation in the anterior cingulate cortex. Moreover, SCA treatment attenuated lipopolysaccharide (LPS)-induced inflammatory response by downregulating interleukin 1β and 6 (IL-1β and IL-6) and tumor necrosis factor-α (TNF-α) levels in BV2 cells...

We present the fabrication and implementation of low-cost optical quality 3D printed lenses, and their application as microscope objectives with different prescriptions. The imaging performance of the 3D printed lenses was benchmarked against commercially available optics including a 20 mm focal length 12.7 mm diameter NBK-7 plano-convex lens used as a low magnification objective, and a separate high magnification objective featuring three 6 mm diameter NBK-7 lenses with different positive and negative focal lengths...