Enhanced cyanophycin accumulation in diazotrophic cyanobacterium through random mutagenesis and tailored selection under varying phosphorus availability.

This study explored a sustainable alternative to the Haber-Bosch process by enhancing the production of the nitrogen-rich polymer cyanophycin (CGP) in the diazotrophic cyanobacterium Nostoc sp. PCC 7120. Applying UV-mutagenesis followed by canavanine selection, we isolate an initial mutant with enhanced CGP accumulation.

Acyl-CoA binding protein is required for lipid droplet degradation in the diatom Phaeodactylum tricornutum.

Diatoms (Bacillariophyceae) accumulate neutral storage lipids in lipid droplets during stress conditions, which can be rapidly degraded and recycled when optimal conditions resume. Since nutrient and light availability fluctuate in marine environments, storage lipid turnover is essential for diatom dominance of marine ecosystems. Diatoms have garnered attention for their potential to provide a sustainable source of omega-3 fatty acids.

Drought Resistant Resting Cysts of Preserves the Species Viability and Its Virulence.

The blastocladialean fungus is a facultative parasite of economically important microalgae and for this reason it has gained a lot of interest. has a complex life cycle which includes vegetative and resting stages. The resting cysts were assumed to play an essential role in survival by resisting drought, but this ability was never tested and the factors that trigger their formation were not evaluated.

Dietary Application of the Microalga Lobosphaera incisa P127 Reduces Severity of Intestinal Inflammation, Modulates Gut-Associated Gene Expression, and Microbiome in the Zebrafish Model of IBD.

Scope: Microalgae are an emerging nutritional resource of biomolecules with potential to alleviate gut inflammation. The study explores the anti-inflammatory and immunomodulatory potential of the microalga Lobosphaera incisa P127, which accumulates a rare omega-6 LC-PUFA dihomo-ɣ-linolenic acid (DGLA) under nitrogen starvation. The therapeutic potential of dietary supplementation with P127 is investigated in the zebrafish model of IBD (TNBS-induced colitis).

GlnS III Is Essential for the Infection of Its Host .

Glutamine synthetase (GlnS) is a key enzyme in nitrogen metabolism. We investigated the effect of the GlnS inhibitor glufosinate on the infection of by the blastocladialean fungus , assuming that interfering with the host nitrogen metabolism will affect the success of the parasite. Complete inhibition of infection, which could be bypassed by the GlnS product glutamine, was observed at millimolar concentrations of glufosinate.

Multiplexed Genome Editing an RNA Polymerase II Promoter-Driven sgRNA Array in the Diatom : Insights Into the Role of StLDP.

CRISPR/Cas9-mediated genome editing has been demonstrated in the model diatom , yet the currently available genetic tools do not combine the various advantageous features into a single, easy-to-assemble, modular construct that would allow the multiplexed targeting and creation of marker-free genome-edited lines. In this report, we describe the construction of the first modular two-component transcriptional unit system expressing Cas9 from a diatom episome, assembled using the Universal Loop plasmid kit for Golden Gate assembly. We compared the editing efficiency of two constructs with orthogonal promoter-terminator combinations targeting the StLDP gene, encoding the major lipid droplet protein of .

Advanced near-zero waste treatment of food processing wastewater with water, carbon, and nutrient recovery.

A near-zero waste treatment system for food processing wastewater was developed and studied. The wastewater was treated using an anaerobic membrane bioreactor (AnMBR), polished using an outdoor photobioreactor for microalgae cultivation (three species were studied), and excess sludge was treated using hydrothermal carbonization. The study was conducted under arid climate conditions for one year (four seasons).

(Chlorophyceae) Divides by Consecutive Multiple Fission Cell-Cycle under Batch and Continuous Cultivation.

Several green algae can divide by multiple fission and spontaneously synchronize their cell cycle with the available light regime. The yields that can be obtained from a microalgal culture are directly affected by cell cycle events. is considered as one of the most promising microalgae for biotechnological applications due to its fast growth and the flexible trophic capabilities.

Infection in Three Economically Valuable Microalgae: Host Preference Correlates with Parasite Fitness.

The blastocladialean fungus parasitizes three microalgae species of economic interest: , and . For the first time, we characterized the developmental stages of isolated fungal propagules in co-culture, finding a generation time of 16 h. We established a patho-system to compare the infection in the three different host species for 48 h, with two different setups to quantify parameters of the infection and parameters of the parasite fitness.

Lipidome Remodeling and Autophagic Respose in the Arachidonic-Acid-Rich Microalga Under Nitrogen and Phosphorous Deprivation.

The green microalga accumulates triacylglycerols (TAGs) with exceptionally high levels of long-chain polyunsaturated fatty acid (LC-PUFA) arachidonic acid (ARA) under nitrogen (N) deprivation. Phosphorous (P) deprivation induces milder changes in fatty acid composition, cell ultrastructure, and growth performance. We hypothesized that the resource-demanding biosynthesis and sequestration of ARA-rich TAG in lipid droplets (LDs) are associated with the enhancement of catabolic processes, including membrane lipid turnover and autophagic activity.

DGLA from the Microalga P127 Modulates Inflammatory Response, Inhibits Expression and Alleviates NO Secretion in RAW264.7 Murine Macrophages.

Microalgae have been considered as a renewable source of nutritional, cosmetic and pharmaceutical compounds. The ability to produce health-beneficial long-chain polyunsaturated fatty acids (LC-PUFA) is of high interest. LC-PUFA and their metabolic lipid mediators, modulate key inflammatory pathways in numerous models.

High Resolution Proteome of Lipid Droplets Isolated from the Pennate Diatom Phaeodactylum tricornutum (Bacillariophyceae) Strain pt4 provides mechanistic insights into complex intracellular coordination during nitrogen deprivation.

Lipid droplets (LDs) are an organelle conserved amongst all eukaryotes, consisting of a neutral lipid core surrounded by a polar lipid monolayer. Many species of microalgae accumulate LDs in response to stress conditions, such as nitrogen starvation. Here, we report the isolation and proteomic profiling of LD proteins from the model oleaginous pennate diatom Phaeodactylum tricornutum, strain Pt4 (UTEX 646).

A Review of Diatom Lipid Droplets.

The dynamic nutrient availability and photon flux density of diatom habitats necessitate buffering capabilities in order to maintain metabolic homeostasis. This is accomplished by the biosynthesis and turnover of storage lipids, which are sequestered in lipid droplets (LDs). LDs are an organelle conserved among eukaryotes, composed of a neutral lipid core surrounded by a polar lipid monolayer.

Characterization and utilization of hydrothermal carbonization aqueous phase as nutrient source for microalgal growth.

This study investigated the feasibility of using hydrothermal carbonization (HTC) aqueous phase as an alternative nutrient source for microalgae cultivation, and the microalgae cultivation capability to treat this complex medium to a level enabling its reuse or discharge. HTC of activated sludge was optimized in terms of the energy content of the solid hydrochar and the nutrient content of the HTC aqueous phase adequate for microalgal growth. Growth rates of Coelastrella sp.

Dihomo-γ-linolenic acid inhibits several key cellular processes associated with atherosclerosis.

Atherosclerosis and its complications are responsible for one in three global deaths. Nutraceuticals show promise in the prevention and treatment of atherosclerosis but require an indepth understanding of the mechanisms underlying their actions. A previous study showed that the omega-6 fatty acid, dihomo-γ-linolenic acid (DGLA), attenuated atherosclerosis in the apolipoprotein E deficient mouse model system.

A novel endogenous selection marker for the diatom Phaeodactylum tricornutum based on a unique mutation in phytoene desaturase 1.

Phaeodactylum tricornutum is a well-developed model diatom for both marine ecology and microalgal biotechnology, which has been enabled by the sequenced genome and the availability of gene delivery tools, such as biolistic transformation and E. coli-mediated conjugation. Till now, these tools have mainly relied on two selectable markers of bacterial origin which confer resistance to antibiotics Zeocin and nourseothricin.

Metabolomic foundation for differential responses of lipid metabolism to nitrogen and phosphorus deprivation in an arachidonic acid-producing green microalga.

The green oleaginous microalga Lobosphaera incisa accumulates storage lipids triacylglycerols (TAG) enriched in the long-chain polyunsaturated fatty acid arachidonic acid under nitrogen (N) deprivation. In contrast, under phosphorous (P) deprivation, the production of the monounsaturated oleic acid prevails. We compared physiological responses, ultrastructural, and metabolic consequences of L.

Non-photochemical quenching in the cells of the carotenogenic chlorophyte Haematococcus lacustris under favorable conditions and under stress.

The microalga Haematococcus lacustris (formerly H. pluvialis) is the richest source of the valuable pigment astaxanthin, accumulated in red aplanospores (haematocysts). In this work, we report on the photoprotective mechanisms in H.

Stimulation and Isolation of (Blastocladiomycota) Propagules and Their Infection Capacity Toward Their Host Under Different Physiological and Environmental Conditions.

(Blastocladiomycota) is a facultative pathogenic chytrid that causes irreversible damage to some green microalgae. Specific attacks leading to culture collapse under different conditions have only been described in the lucrative microalga , while generating biomass for ketocarotenoid astaxanthin production, both indoors and outdoors. In order to manage the infection, parasite propagules (zoospores/amoeboid swarmers), the initiators of the disease, must be studied.

Long-Chain Polyunsaturated Fatty Acids in the Green Microalga Lobosphaera incisa Contribute to Tolerance to Abiotic Stresses.

Lobosphaera incisa is a green microalga that accumulates high levels of the valuable omega-6 long-chain polyunsaturated fatty acids (LC-PUFA) arachidonic acid (ARA, 20:4n-6) in triacylglycerols (TAG) under nitrogen (N) starvation. LC-PUFA accumulation is a rare trait in photosynthetic microalgae with insufficiently understood physiological significance. In this study, RNAi was attempted, for the first time in L.

A hypothesis about the origin of carotenoid lipid droplets in the green algae Dunaliella and Haematococcus.

Hypercarotenogenesis in green algae evolved by mutation of PSY that increased its transcription at high light, disintegration of the eyespot in Dunaliella and acquisition of the capacity to export carotenoids from chloroplasts in Haematococcus. Carotenoids (Car) are lipid-soluble pigments synthesized in plants, algae, bacteria and fungi. Car have strong antioxidative properties and as such are utilized to reduce the danger of different diseases in humans.

Are Thraustochytrids algae?

Thraustochytrids, a heterotrophic fungus-like clade of Stramenopiles, are becoming an increasingly important source of polyunsaturated fatty acids (PUFAs) for biotechnological industries. PUFA rich oils from these organisms are subsequently referred to in some literature and marketing sources as being derived from 'algae', in spite of their non-photosynthetic source organism. In this review, we attempt to disentangle the evolutionary relationship of the Thraustochytrids from other Protists, demonstrating that there is no scientific basis for the aforementioned misnomer.

Arachidonic acid is important for efficient use of light by the microalga Lobosphaera incisa under chilling stress.

The oleaginous microalga Lobosphaera incisa (Trebouxiophyceae, Chlorophyta) contains arachidonic acid (ARA, 20:4 n-6) in all membrane glycerolipids and in the storage lipid triacylglycerol. The optimal growth temperature of the wild-type (WT) strain is 25°C; chilling temperatures (≤15°C) slow its growth. This effect is more pronounced in the delta-5-desaturase ARA-deficient mutant P127, in which ARA is replaced with dihomo-γ-linolenic acid (DGLA, 20:3 n-6).

Cloning, molecular characterization, and phylogeny of two evolutionary distinct glutamine synthetase isoforms in the green microalga Haematococcus pluvialis (Chlorophyceae).

Haematococcus pluvialis (Chlorophyta) is a widely used microalga of great economic potential, yet its molecular genetics and evolution are largely unknown. We present new detailed molecular and phylogenetic analysis of two glutamine synthetase (GS) enzymes and genes (gln) under the Astaxanthin-inducing conditions of light- and nitrogen-stress. Structure analysis identified key residues and confirmed two decameric GS holoenzymes, a cytoplasmic enzyme, termed GS , and a plastidic form, termed GS , due to chloroplast-transit peptides at its N-terminus.