LPS-Induced Mortality in Zebrafish: Preliminary Characterisation of Common Fish Pathogens.

Disease outbreaks are a common problem in aquaculture, with serious economic consequences to the sector. Some of the most important bacterial diseases affecting aquaculture are caused by Gram-negative bacteria including spp. (vibriosis), (photobacteriosis), spp.

Towards the rate limit of heterologous biotechnological reactions in recombinant cyanobacteria.

Background: Cyanobacteria have emerged as highly efficient organisms for the production of chemicals and biofuels. Yet, the productivity of the cell has been low for commercial application. Cyanobacterial photobiotransformations utilize photosynthetic electrons to form reducing equivalents, such as NADPH-to-fuel biocatalytic reactions.

Subcellular compartmentalization of aluminum reduced its hazardous impact on rye photosynthesis.

Aluminum (Al) toxicity limits crops growth and production in acidic soils. Compared to roots, less is known about the toxic effects of Al in leaves. Al subcellular compartmentalization is also largely unknown.

Novel protein carrier system based on cyanobacterial nano-sized extracellular vesicles for application in fish.

Aquaculture has been one of the fastest-growing food industry sectors, expanding at the pace of consumers' demands. To promote safe and effective fish growth performance strategies, and to stimulate environmentally friendly solutions to protect fish against disease outbreaks, new approaches are needed to safeguard fish welfare, as well as farmers and consumers interests. Here, we tested the use of cyanobacterial extracellular vesicles (EVs) as a novel nanocarrier system of heterologous proteins for applications in fish.

Isolation and Characterization of Cyanobacterial Extracellular Vesicles.

Cyanobacteria are a diverse group of photosynthetic, Gram-negative bacteria that play critical roles in global ecosystems and serve as essential biotechnology models. Recent work has demonstrated that both marine and freshwater cyanobacteria produce extracellular vesicles - small membrane-bound structures released from the outer surface of the microbes. While vesicles likely contribute to diverse biological processes, their specific functional roles in cyanobacterial biology remain largely unknown.

Heterologous Production of Glycine Betaine Using sp. PCC 6803-Based Chassis Lacking Native Compatible Solutes.

Among compatible solutes, glycine betaine has various applications in the fields of nutrition, pharmaceuticals, and cosmetics. Currently, this compound can be extracted from sugar beet plants or obtained by chemical synthesis, resulting in low yields or high carbon footprint, respectively. Hence, in this work we aimed at exploring the production of glycine betaine using the unicellular cyanobacterium sp.

The Role of Outer Membrane Protein(s) Harboring SLH/OprB-Domains in Extracellular Vesicles' Production in sp. PCC 6803.

Cyanobacteria are a group of photosynthetic prokaryotes that contribute to primary production on a global scale. These microorganisms release vesicles to the extracellular environment, spherical nanosized structures, derived essentially from the outer membrane. Even though earlier works in model Gram-negative bacteria have hypothesized that outer membrane stability is crucial in vesicle formation, the mechanisms determining vesicle biogenesis in cyanobacteria remain unknown.

CRISPRi as a Tool to Repress Multiple Copies of Extracellular Polymeric Substances (EPS)-Related Genes in the Cyanobacterium sp. PCC 6803.

The use of the versatile cyanobacterial extracellular polymeric substances (EPS) for biotechnological/biomedical applications implies an extensive knowledge of their biosynthetic pathways to improve/control polymer production yields and characteristics. The multiple copies of EPS-related genes, scattered throughout cyanobacterial genomes, adds another layer of complexity, making these studies challenging and time-consuming. Usually, this issue would be tackled by generating deletion mutants, a process that in cyanobacteria is also hindered by the polyploidy.

Expression and activity of heterologous hydroxyisocaproate dehydrogenases in sp. PCC 6803 Δ.

Exploiting light to drive redox reactions is currently a hot topic since light is considered as an environmentally friendly source of energy. Consequently, cyanobacteria, which can use light e.g.

Complete Genome Sequence of Two Deep-Sea Isolates from Madeira Archipelago and Evaluation of Their Biosynthetic Potential.

The deep-sea constitutes a true unexplored frontier and a potential source of innovative drug scaffolds. Here, we present the genome sequence of two novel marine actinobacterial strains, MA3_2.13 and S07_1.

Comparison of alternative integration sites in the chromosome and the native plasmids of the cyanobacterium Synechocystis sp. PCC 6803 in respect to expression efficiency and copy number.

Background: Synechocystis sp. PCC 6803 provides a well-established reference point to cyanobacterial metabolic engineering as part of basic photosynthesis research, as well as in the development of next-generation biotechnological production systems. This study focused on expanding the current knowledge on genomic integration of expression constructs in Synechocystis, targeting a range of novel sites in the chromosome and in the native plasmids, together with established loci used in literature.

Internal Illumination to Overcome the Cell Density Limitation in the Scale-up of Whole-Cell Photobiocatalysis.

Cyanobacteria have the capacity to use photosynthesis to fuel their metabolism, which makes them highly promising production systems for the sustainable production of chemicals. Yet, their dependency on visible light limits the cell-density, which is a challenge for the scale-up. Here, it was shown with the example of a light-dependent biotransformation that internal illumination in a bubble column reactor equipped with wireless light emitters (WLEs) could overcome this limitation.

Development of an ecotoxicological test procedure for soil microalgae.

Since the 80s, ISO and OECD organizations have been developing guidelines for assessing the toxicity of new and existing chemical substances to soil biota. Up to now, any of these guidelines had soil algae as test organisms. Nevertheless, microalgae are relevant components of soil microbial communities and soil biological crusts (BSC) with a great contribution to different soil functions and ecosystem services.

Surface activation of medical grade polyurethane for the covalent immobilization of an anti-adhesive biopolymeric coating.

Hospital-acquired infections are still a major concern worldwide, being frequently related to bacterial biofilm formation on medical devices, and thus difficult to eradicate with conventional antimicrobial treatments. Therefore, infection-preventive solutions based on natural polymers are being investigated. Recently, a marine cyanobacterium-derived polymeric coating (CyanoCoating) has demonstrated great anti-adhesive potential when immobilized onto gold model substrates.

The role of positive charged residue in the proton-transfer mechanism of two-domain laccase from Ac-993.

Multi-copper oxidases are capable of coupling the one-electron oxidation of four substrate equivalents to the four-electron reduction of dioxygen to two molecules of water. This process takes place at the trinuclear copper center of the enzymes. Previously, the main catalytic stages for three-domain (3D) laccases have been identified.

Biocompatibility of the Biopolymer Cyanoflan for Applications in Skin Wound Healing.

There is a great demand for the development of novel wound dressings to overcome the time and costs of wound care performed by a vast number of clinicians, especially in the current overburdened healthcare systems. In this study, Cyanoflan, a biopolymer secreted by a marine unicellular cyanobacterium, was evaluated as a potential biomaterial for wound healing. Cyanoflan effects on cell viability, apoptosis, and migration were assessed in vitro, while the effect on tissue regeneration and biosafety was evaluated in healthy Wistar rats.

Absence of KpsM (Slr0977) Impairs the Secretion of Extracellular Polymeric Substances (EPS) and Impacts Carbon Fluxes in sp. PCC 6803.

Many cyanobacteria produce extracellular polymeric substances (EPS), composed mainly of heteropolysaccharides, that play a variety of physiological roles, being crucial for cell protection, motility, and biofilm formation. However, due to their complexity, the EPS biosynthetic pathways as well as their assembly and export mechanisms are still far from being fully understood. Here, we show that the absence of a putative EPS-related protein, KpsM (Slr0977), has a pleiotropic effect on sp.

Untargeted Lipidomics Analysis of the Cyanobacterium sp. PCC 6803: Lipid Composition Variation in Response to Alternative Cultivation Setups and to Gene Deletion.

Cyanobacteria play an important role in several ecological environments, and they are widely accepted to be the ancestors of chloroplasts in modern plants and green algae. Cyanobacteria have become attractive models for metabolic engineering, with the goal of exploring them as microbial cell factories. However, the study of cyanobacterial lipids' composition and variation, and the assessment of the lipids' functional and structural roles have been largely overlooked.

Comparative Genomics Discloses the Uniqueness and the Biosynthetic Potential of the Marine Cyanobacterium .

Baeocytous cyanobacteria (Pleurocapsales/Subsection II) can thrive in a wide range of habitats on Earth but, compared to other cyanobacterial lineages, they remain poorly studied at genomic level. In this study, we sequenced the first genome from a member of the genus - LEGE 07179, a recently described species isolated from the Portuguese foreshore. This genome is the largest of the thirteen baeocyte-forming cyanobacterial genomes sequenced so far, and diverges from the most closely related strains.

Extracellular Vesicles: An Overlooked Secretion System in Cyanobacteria.

In bacteria, the active transport of material from the interior to the exterior of the cell, or secretion, represents a very important mechanism of adaptation to the surrounding environment. The secretion of various types of biomolecules is mediated by a series of multiprotein complexes that cross the bacterial membrane(s), each complex dedicated to the secretion of specific substrates. In addition, biological material may also be released from the bacterial cell in the form of vesicles.

Natural Cyanobacterial Polymer-Based Coating as a Preventive Strategy to Avoid Catheter-Associated Urinary Tract Infections.

Catheter-associated urinary tract infections (CAUTIs) represent about 40% of all healthcare-associated infections. Herein, the authors report the further development of an infection preventive anti-adhesive coating (CyanoCoating) meant for urinary catheters, and based on a natural polymer released by a marine cyanobacterium. CyanoCoating performance was assessed against relevant CAUTI etiological agents, namely Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, methicillin resistant Staphylococcus aureus (MRSA), and Candida albicans in the presence of culture medium or artificial urine, and under biofilm promoting settings.

Glyphosate-dependent effects on photosynthesis of Solanum lycopersicum L.-An ecophysiological, ultrastructural and molecular approach.

This study aimed to assess the toxicity of glyphosate (GLY; 0, 10, 20 and 30 mg kg) in Solanum lycopersicum L., particularly focusing on the photosynthetic metabolism. By combining ecophysiological, ultrastructural, biochemical and molecular tools, the results revealed that the exposure of tomato plants to GLY led to alterations in leaf water balance regulation [increasing stomatal conductance (g) and decreasing water use efficiency (WUE) at higher concentrations] and induced slight alterations in the structural integrity of cells, mainly in chloroplasts, accompanied by a loss of cell viability.