Algal Research-Biomass Biofuels and Bioproducts最新文献

A robust cell wall and well-organized thylakoid cyanobacteria can be candidates as a promising resource for C-phycocyanin (C-PC) and intracellular applications in various biotechnological areas. However, the development of extraction techniques with minimal chemical contamination to obtain the components remains an ongoing challenge. This study aimed to assess the efficacy of C-PC and intracellular extraction from Ocillatoria okeni TISTR8549 utilizing freezing-thaw (FT), pulsed electric field (PEF), and high-pressure homogenization (HPH) techniques. Additionally, the potential of O. okeni extract as a supplement and substitute for fetal bovine serum (FBS) in HaCaT cell culture was investigated. FT appeared to be the most proper method for C-PC extraction, yielding the highest purity and yield, although requiring 18 cycles for product accomplishment. PEF seemed unsuitable for intracellular component extraction from cyanobacteria with thick cell walls. The need for increased pulses resulted in thermal elevation and prolonged incubation times led to protein degradation. HPH proves to be an effective method for intracellular extraction, yielding high protein content suitable for the potential substitution of FBS in mammalian cell culture. Particularly, increasing pressure during HPH extraction leads to a decrease in protein yield. Resazurin and SRB assays revealed that adding algal extract in culture medium at concentrations of 1 % (w/v) improved HaCaT cell viability without disrupting cell morphology and metabolic processes. However, substituting algal extract in FBS resulted in cell proliferation decrease. Therefore, supplementing O. okeni extract during cell culture improved HaCaT cell proliferation, but it was unsuitable substitute for FBS in the culture medium. However, the feasibility of employing algal extracts as FBS replacements in cell culture is interesting and warrants further detailed investigation into the specific intracellular components that could serve as substitutes for FBS. Such an approach could offer an alternative source, mitigating ethical concerns and reducing costs associated with FBS usage.

Marine diatom Chaetoceros gracilis have been known as the key player regulating the nutritional content of aquaculture species. Being able to synthesize an array of high value bioactive compounds like amino acids, lipids, terpenoids and polysaccharides, it also serves as potential therapeutic and nutraceutical agent. This in silico-based study elucidates the interactive association of different compounds, proteins and pathways of the diatom C. gracilis through an integrated network pharmacology and molecular docking approach. According to the Network analysis of the 41 compounds detected, saturated hydrocarbons, diterpenoids and phenolic compounds scored the highest degree (score > 140). These compounds were further coded for approximately 349 protein targets and almost 490 different pathways. HSP90AA1, STAT3, HIF1A, MTOR, ESR1, PIK3CA, MAPK1 and PTGS2 secured highest degree of protein-protein interaction according to STRING database. The gene enrichment analysis further revealed that these proteins were closely associated with metabolic pathways like Pathways in cancer, neuroactive ligand-receptor interaction, calcium and cAMP signaling pathway, PI3K-Akt signaling pathway, Alzheimer's disease and pathways of neurodegeneration which played an instrumental role in the metabolism of diseases and disorders like cancers of breast, prostrate, and liver, schizophrenia and other mental and hypertensive disorders. Furthermore, the molecular docking and toxicity assessment of a few novel compounds was done with mTOR and HSP90AA1 which revealed promising and stable interactions. Thus, this study provides the first in silico insight outlining the anti-cancerous and neuroprotective potential of novel bioactive compounds derived from marine diatom C.gracilis.

Microalgae have been studied due to their biotechnological potential in agriculture and could be an important source of biostimulants. Similarly, other compounds, such as B₃ vitamins (niacin and nicotinamide), have been found to enhance the biostimulant effect on plant growth. This study aimed to evaluate the potentiating effect of Chlorella vulgaris bioinput as a growth biostimulant in the production of basil seedlings (Ocimum basilicum L.) with the addition of vitamin B₃. The experiment was conducted in a protected environment on the Mato Grosso do Sul State University - Cassilândia University Unit and the Sustainable Development Center of the Bolsão Sul Mato Grossense. The experiment was conducted in a completely randomized design, with four treatments: control, microalgae bioinput (Bio), vitamin B₃ (niacin + nicotinamide), and joint application of Bio + vitamin B₃, with four replications. The agronomic traits of growth and photosynthetic pigments of the seedlings were evaluated. For the growth of basil seedlings, applying bio input combined with vitamin B₃ had a significant impact (p < 0.05) on several variables. This combination increased seedling height, stem diameter, root dry matter, shoot dry matter, total dry matter, and Dickson quality index (DQI) by 19 %, 11 %, 11 %, 41 %, 37 %, and 17 %, respectively, as well as regulating the production of photosynthetic pigments in basil. The results indicate that bioinput combined with niacin and nicotinamide stimulates various plant growth traits, favoring the production of seedlings.

The effects of the Instant Controlled Pressure Drop (DIC) technology on the recovery of natural compounds from the brown seaweed Sargassum muticum (Yendo) Fensholt 1955 (Ochrophytina, Fucales) were investigated. Fresh biomass of S. muticum was collected on the Brittany Coast, France. Both fresh and Air Impingement-Dried (AID) thalli of 3 and 10 cm length were submitted to DIC during 20 s or 90 s of processing time under 100 or 800 kPa of saturated steam pressure. DIC treatment significantly improved the extraction of sulphate groups at 90 s, and carotene at 20 s under 100 kPa in thalli of 10 cm. While, coupling AID to DIC, the content of neutral sugars, proteins and antioxidants were higher in AID + DIC treatments. Further, a significant increase of 20 % in fucose-containing sulfated polysaccharides and 30 % in sodium alginate under 100 kPa during 90 s, compared to oven-dried, was observed. The biomass of the invasive S. muticum treated by DIC and AID + DIC represented a valuable contribution for extraction of natural compounds. Advantages for industrial integration of DIC were discussed.

N-glycosylation is a major post-translational modification of proteins that has a crucial influence on cell targeting, activity, and half-life. This process starts in the endoplasmic reticulum where an oligosaccharide precursor is added to the newly synthesized protein and continues in the Golgi apparatus where the N-linked carbohydrate sequences are processed. Importantly, the most approved recombinant pharmaceutical proteins (so-called biologics) are glycoproteins mainly currently produced in mammalian cells which is a lengthy, costly, and complex process. Today, several microalgae such as the diatom Phaeodactylum tricornutum, and the green microalgae Chlamydomonas reinhardtii, Chlorella vulgaris, and Dunaliella salina are considered as efficient and eco-friendly alternative platforms for the production of biologics. However, unlike for C. reinhardtii, C. vulgaris, and P. tricornutum, there is to date no data reported regarding the protein N-glycosylation pathway in D. salina. Here, we first investigated the protein N-glycosylation in this green microalga by MALDI-TOF mass spectrometry. These analyses showed that proteins from D. salina are N-glycosylated with Man₅GlcNAc₂ oligomannoside. Using genome mining approaches, we then identified genes encoding proteins involved in the N-glycosylation pathways in D. salina. Genetic similarities and phylogenetic relationships of the putative sequences with homologues from C. reinhardtii, P. tricornutum, and humans were investigated. These data revealed that in D. salina the biosynthesis of nucleotide sugars and N-glycan biosynthesis share mainly similarities with the GnT I-independent pathway of C. reinhardtii that gives rise to the synthesis of a non-canonical oligomannoside Man₅GlcNAc₂. Although an α(1,3)-fucosyltransferase is identified in the D. salina genome, impairment of the cytosolic GDP-Fuc biosynthesis prevents the Golgi fucosylation of N-glycans. Taken together, these data demonstrated that proteins from D. salina are homogeneously N-glycosylated with a non-canonical Man₅GlcNAc₂.

Neurotoxin β-N-methylamino-L-alanine (BMAA) has been implicated as a major inducer of human neurodegenerative diseases. In recent years, marine diatoms were verified to produce BMAA-containing proteins. It will be an important cue to elucidate the subcellular distribution of BMAA in marine diatoms for disclosing its biosynthesis pathway. In this study, three species of Thalassiosira (T. andamanica, T. allenii and T. minima) were used to investigate the subcellular distribution of BMAA in organelles. Results showed that the crushing efficiency of diatoms was species-specific and increased with the rise of ultrasonic intensity of 22, 50 and 100 W (pulse = 0.2 s/s, 4 min), of which T. andamanica and T. allenii obtained the lowest and highest crushing efficiency, respectively. Interestingly, although T. allenii and T. minima were more efficiently crushed at 50 W and 100 W power (pulse = 0.2 s/s), their organelles were largely fragmented, which was verified by cytochrome c oxidase (CCO) enzyme analysis and transmission electron microscopy (TEM) observation. Their organelles were not fragmented only at 22 W. However, the crushing efficiency of T. andamanica was more reliable, and its organelles were essentially intact and only damaged at 100 W. Analysis of the BMAA-containing proteins showed that these proteins exclusively distribute in the Golgi and endoplasmic reticulum (ER) organelles. The nearly intact membranes of nucleus, mitochondria, Golgi and ER organelles testified that the absence of BMAA in other organelles was not caused by damage of nucleus or mitochondria. Results demonstrated that the BMAA-containing proteins were produced and accumulated in the ER and Golgi of diatoms.

C-phycocyanin (C-PC) is a highly valuable bioproduct from the cyanobacterium Arthrospira platensis. A crucial factor affecting growth and C-PC production yield is nitrogen nutrients. In this work, an ODE-based dynamic model was constructed to simulate the effect of ammonium concentrations in a batch system on cyanobacterial growth and C-PC production. The model included dynamic regulation of the ammonium transporter and key enzymes involved in the nitrogen assimilation pathway. The prediction of C-PC production, cyanobacterial growth, and remaining ammonium concentration over 24 h strongly correlated with experimental data. Furthermore, the model was able to capture the response of genes involved in ammonium assimilation and C-PC production, as well as the primary metabolites. The dynamic interplay among ammonium, glutamine, and glutamate levels reflects the complexity of nitrogen metabolism in regulating the transcription of genes involved in ammonium uptake, assimilation, and C-PC synthesis and degradation, thus highlighting the cellular response to nitrogen stress. These findings provide a foundation for understanding these biological processes and offer a potential tool for further exploring the complex relationship between nitrogen availability and C-PC accumulation in A. platensis C1 using ammonium as a nitrogen source.

Cancer and antimicrobial resistance are pressing global health concerns, with cancer ranking as a foremost reason of death across the world, estimated to be about 10 million in 2020, while antimicrobial resistance (AMR) poses a significant threat, with projected deaths attributed to AMR set to exceed 10 million by 2050. Recent research has highlighted Actinomyces, Bacteroidetes, Proteobacteria, and Cyanobacteria as promising sources of therapeutic compounds. Among cyanobacteria, the genus Leptolyngbya has garnered relatively less attention. Leptolyngbya is a polyphyletic in nature and widely distributed across various ecosystems. Although over 140 species have been identified within this genus, its systematic position has only recently been clarified. Leptolyngbya's diverse metabolite spectrum, including compounds with antioxidant, antimicrobial, and antiproliferative properties, as discussed in this review, makes it a valuable candidate for drug discovery. However, challenges in laboratory cultivation have hindered the identification of novel metabolites from Leptolyngbya, which would have been otherwise discovered. Hence, this article focuses on the antiproliferative and antimicrobial activities of the diverse genus Leptolyngbya, as well as the cutting-edge technologies that have the potential to expand the untapped metabolite spectrum of the genus.

Cyanobacteria are a group of photosynthetic bacteria and a rich secondary metabolites source. The Bank of Algae and Cyanobacteria of the Azores (BACA) culture collection holds a significant number of strains, including many novel genera and species. 56 strains from freshwater, brackish, and thermal habitats were selected, and grown under standard conditions. Biomass was extracted with methanol, and cytotoxicity was assessed on two carcinoma cell lines, HepG2 and HCT116. The reduction of lipids was tested in zebrafish larvae, and in a steatosis model with fatty acid overloaded human liver cells. The cyanobacterial metabolome was analyzed by HR-ESI-LC-MS/MS and compared using CompareMS2. High similarities were observed in strains of the same genus when isolated from similar habitats, clustering in concordance to the taxonomical order, while no relation could be observed between strains from different genera originated from the same habitat. The extracts of Cyanobium sp. BACA0019, Pseudocalidococcus azoricus BACA0433 and Pegethrix atlantica BACA0077 reduced neutral lipids >40 % in zebrafish at 25 μg/mL, while from Symphyonema sp. BACA0090 and Aliinostoc sp. BACA0355 induced mortality. Lipid reduction in the steatosis model was observed in many strains, with significant results varying from 50 % to 100 %. Several strains reduced cell viability with the strongest effects from Scytonematopsis sp. BACA0005 (HepG2, 59.8 % and HCT116, 68.1 %), Aliinostoc sp. BACA0035 (HepG2, 43.3 %, and HCT116, 59.4 %) and Aliinostoc sp. BACA0355 (HepG2, 46.2 %, and HCT116, 75.5 %). The feature-based molecular networking identified several cluster of mass peaks related to the observed bioactivities. Chlorophyll derivatives and glycerolipids from Cyanobium sp. BACA0019, Pseudocalidococcus azoricus BACA0433 and Pegethrix atlantica BACA0077 were correlated with the reduction of lipids in zebrafish larvae, while several oligopeptides and fatty amides of Symphyonema sp. BACA0090 and Aliinostoc sp. BACA0355 with toxicity. Many clusters associated to the bioactivities remained unidentified, which may represent novel compounds, highlighting the chemodiversity of the BACA culture collection.

Mutations are the origin of genetic diversity and are fundamental parameters needed to understand the molecular evolution of species. Estimations of mutation rates have been conducted for many diverse taxa, although rates in several major eukaryotic lineages remain unexplored. Here, the first estimation is reported of the spontaneous mutation rate for the multicellular eukaryote red alga, Pyropia yezoensis, which exhibits a complex life cycle. An estimated mutation rate of 2.97 × 10⁻⁸ (95 % CI: 2.16 × 10⁻⁸–3.99 × 10⁻⁸) per site per generation was generated for the primary life cycle, the sexual cycle, which is the highest sexual mutation rate among published sexual plants. Combined with tetrad analysis, meiosis I was identified as the primary period responsible for the high mutation rate during the complex life cycle of P. yezoensis. This result provides direct evidence for the “meiosis is mutagenic” hypothesis for multicellular organisms. The accurate estimate of the mutation rate of P. yezoensis also informs several immediate applications. Based on the above estimate, the effective population size (N_e) of P. yezoensis was estimated at about 19,000, with extensive haploid phases and asexual reproduction through monospores possibly leading to linked selection that may reduce the genome-wide genetic diversity of P. yezoensis and consequently influence N_e estimation. Lastly, P. yezoensis was estimated to have diverged from P. haitanensis about 4.2 Ma, representing a more recent date than estimates from fossil-calibrated phylogenies. These findings provide valuable new information for understanding the evolution of red algae, in addition to the underlying mechanism of mutations.