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Pyropia yezoensis is an important macroalga because of its extensive global distribution and economic importance. Color is an important trait in the thalli of P. yezoensis, it is also an effective marker to identify the hybridization in genetic breeding. In this study, a high-density genetic linkage map was constructed based on high-throughput single nucleotide polymorphism (SNP) markers, and used for analyzing the quantitative trait loci (QTLs) of red color trait in the thalli of P. yezoensis. The conchospore undergoes meiosis to develop into an ordered tetrad, and each cell has a haploid phenotype and can grow into a single individual. Based on this theory, F1 haploid population was used as the mapping population. The map included 531 SNP markers, 394.57 cM long on average distance of 0.74 cM. Collinear analysis of the genetic linkage map and the physical map indicated that the coverage between the two maps was 79.42%. Furthermore, QTL mapping identified six QTLs for the chromosomal regions associated with the red color trait of the thalli. The value of phenotypic variance explained (PVE) by an individual QTL ranged from 4.71%–63.11%. And QTL qRed-1-1, with a PVE of 63.11%, was considered the major QTL. Thus, these data may provide a platform for gene and QTL fine mapping, and marker-assisted breeding in P. yezoensis in the future.

Neoporphyra haitanensis is an economically important red seaweed that inhabits upper intertidal zones. The thallus tolerates extreme fluctuating environmental stresses (e.g., surviving more than 80% water loss during low tides). To elucidate the global molecular responses relevant to this outstanding desiccation tolerance, a quantitative proteomics analysis of N. haitanensis under different desiccation treatments as well as rehydration was performed. According to the clustering of expression patterns and the functional interpretation of the 483 significantly differentially expressed proteins, a three-stage cellular response to desiccation stress and subsequent rehydration was proposed. Stage I: at the beginning of water loss, multiple signal transduction pathways were triggered including lipid signaling, protein phosphorylation cascades, and histone acetylation controlling acetate biosynthesis to further modulate downstream hormone signaling. Protein protection by peptidyl-prolyl isomerase and ROS scavenging systems were also immediately switched on. Stage II: with the aggravation of stress, increases in antioxidant systems, the accumulation of LEA proteins, and the temporary biosynthesis of branched starch were observed. Multiple enzymes involved in redox homeostasis, including peroxiredoxin, thioredoxin, ascorbate peroxidase, superoxide dismutase, glutathione peroxidase, and glutathione reductase, were hypothesized to function in specific cellular compartments. Stage III: when the desiccated thalli had rehydrated for 30 mins, photosynthesis and carbon fixation were recovered, and antioxidant activities and protein structure protection were maintained at a high level. This work increases the understanding of the molecular responses to environmental stresses via a proteomic approach in red seaweeds and paves the way for further functional studies and genetic engineering.

The genus Pyropia contains several important cultivated species. Genetic research in nori species has mainly focused on the cell nucleus, with few studies on organelles (chloroplast and mitochondria). Due to the high copy numbers of organelles in cells, which influence the development and traits of algae, it is necessary to study their genetic mechanism. In this study, the marine red alga Pyropia yezoensis, an important economic macroalga, was selected as the study object. To investigate organelle (chloroplast and mitochondria) inheritance in P. yezoensis, the wild type RZ (maternal strain) was crossed with the red mutant HT (paternal strain) and 30 color-sectors from 11 F1 gametophytic blades were examined. The complete chloroplast and mitochondrial genomes of the red mutant (HT) were assembled for the first time. One reliable and stable single nucleotide polymorphism (SNP) loci filtrated by bioinformatics analysis was used as a molecular marker for chloroplast and mitochondrial DNA, respectively, in subsequent experiments. PCR amplification and sequence analysis showed that the haplotypes of color-sectors detected were consistent with those of the maternal parent, confirming that both chloroplast and mitochondrial genomes were inherited maternally in P. yezoensis. The inheritance pattern of organelles in P. yezoensis can be used to guide the hybridization and breeding of nori. Additionally, the organelle SNP markers developed in this study can be applied in subsequent genetic research.

Microorganisms plays an important role in the growth of Pyropia haitanensis. To understand the structural and functional diversity of the microorganism community of P. haitanensis (PH40), the associated metabolic pathway network in cluster of orthologous groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG), and carbohydrate-active enzymes (CAZymes) were explored in metagenomic analysis. DNA extraction from gametophytes of P. haitanensis was performed first, followed by library construction, sequencing, preprocessing of sequencing data, taxonomy assignment, gene prediction, and functional annotation. The results show that the predominant microorganisms of P. haitanensis were bacteria (98.98%), and the phylum with the highest abundance was Proteobacteria (54.64%), followed by Bacteroidetes (37.92%). Erythrobacter (3.98%) and Hyunsoonleella jejuensis (1.56%) were the genera and species with the highest abundance of bacteria, respectively. The COG annotation demonstrated that genes associated with microbial metabolism was the predominant category. The results of metabolic pathway annotation show that the ABC transport system and two-component system were the main pathways in the microbial community. Plant growth hormone biosynthesis pathway and multi-vitamin biosynthesis functional units (modules) were the other important pathways. The CAZyme annotation revealed that the starch might be an important carbon source for microorganisms. Glycosyl transferase family 2 (GT2) and glycosyl transferase family 3 (GT3) were the highly abundant families in glucoside transferase superfamily. Six metagenome-assembled genomes containing enzymes involved in the biosynthesis of cobalamin (vitamin B12) and indole-3-acetic acid were obtained by binning method. They were confirmed to belong to Rhodobacterales and Rhizobiales, respectively. Our findings provide comprehensive insights into the microorganism community of Pyropia.

Pyropia haitanensis (Bangiales, Rhodophyta), a major economically important marine crop, is also considered as an ideal research model of Rhodophyta to address several major biological questions such as sexual reproduction and adaptation to intertidal abiotic stresses. However, comparative genomic analysis to decipher the underlying molecular mechanisms is hindered by the lack of high‐quality genome information. Therefore, we integrated sequencing data from Illumina short‐read sequencing, PacBio single‐molecule sequencing and BioNano optical genome mapping. The assembled genome was approximately 53.3 Mb with an average GC% of 67.9%. The contig N50 and scaffold N50 were 510.3 kb and 5.8 Mb, respectively. Additionally, 10 superscaffolds representing 80.9% of the total assembly (42.7 Mb) were anchored and orientated to the 5 linkage groups based on markers and genetic distance; this outcome is consistent with the karyotype of five chromosomes (n = 5) based on cytological observation in P. haitanensis. Approximately 9.6% and 14.6% of the genomic region were interspersed repeat and tandem repeat elements, respectively. Based on full‐length transcriptome data generated by PacBio, 10,903 protein‐coding genes were identified. The construction of a genome‐wide phylogenetic tree demonstrated that the divergence time of P. haitanensis and Porphyra umbilicalis was ~204.4 Ma. Interspecies comparison revealed that 493 gene families were expanded and that 449 were contracted in the P. haitanensis genome compared with those in the Po. umbilicalis genome. The genome identified is of great value for further research on the genome evolution of red algae and genetic adaptation to intertidal stresses.

To explore effective physiological indexes to distinguish the resistant lines and susceptible lines of Pythium porphyrae, the causal agent of red rot disease of Pyropia yezoensis, and establish the disease-resistance breeding strategy, we obtained and analyzed the candidate resistant and susceptible lines by population selection. Gametophytes of the candidate lines were cultured in seawater containing Pyt. porphyrae zoospores. Antioxidase activities, including superoxide dismutase (SOD), peroxidase (POD) and polyphenol oxidase (PPO), were measured and compared between the two lines before and after infection. In the resistant lines, SOD and POD activities increased and then decreased, but PPO activity rose with the prolongation of the infection time. The phenylalanine ammonia lyase (PAL) activities also increased and then decreased after infection, but it had significantly different expression in the two lines without pathogen attack. The synthesis rates of β-1–3-glucanase, and cell-wall degrading enzyme were different from each other between the two lines after infection of Pyt. porphyrae. Comparison in the contents of malondialdehyde (MDA) and reactive oxygen species (ROS) in the two lines showed that, the two contents varied synchronously in response to the pathogen attack. Changes of these enzymes activities or contents demonstrated that Pyr. yezoensis could resist against the pathogen of Pyt. porphyrae with the antioxidant defense capacity. In addition, β-1.3-glucanase content showed extremely significant difference between the two lines, and the PAL had consistent expression difference. Therefore, phenylalanine ammonia lyase (PAL) and β-1–3-glucanase can be considered as an effective index to distinguish susceptible line and resistant line, with which the workload of the resistant breeding could be reduced in the future.

Pyropia yezoensis is an economically important marine macroalgae, naturally distributed in the upper intertidal zone. Owing to the nature of its habitat, the thallus will periodically be exposed to seawater or atmosphere, and can lose up to 95% of its cellular water content. This makes the alga an ideal research model to investigate the mechanisms of desiccation tolerance. In this study, we investigated the response mechanisms to dehydration and rehydration stresses at the transcription level in Pyropia yezoensis. The differently expressed genes were analyzed based on the different functions of encoding proteins: effector proteins (chloroplast proteins, macromolecular protective substances, and toxicity degradation enzymes) and regulatory proteins (protein kinases and phosphatases). Under osmotic stress, the unigenes related to photosynthesis were down-regulated significantly while those encoding glutathione transferase, superoxide dismutase and heat shock proteins were up-regulated significantly. We inferred that the photosynthetic activity was reduced to prevent damage caused by photosynthetic by-products and that the expression of antioxidant enzyme was increased to prevent the damage associated with reactive oxygen species. Additionally, unigenes encoding serine/threonine kinases and phospholipases were up-regulated in response to osmotic stress, indicating that these kinases play an important role in osmotolerance. Our work will serve as an essential foundation for the understanding of desiccation tolerance mechanisms in Pyropia yezoensis in the upper intertidal zones of rocky coasts.

The community dynamics and potential carbon fixation of intertidal macroalgae were investigated monthly from April 2014 to April 2015 in the northwest coast of Yellow Sea. Seasonal variations in biomass and carbon fixation were presented and showed close relationship with community structure. The carbon fixation rate ranged from 0.48±0.13 mg C/(gFW·d) to 4.35±0.12 mg C/(gFW·d). Sargassum thunbergii, Chondrus ocellatus and Ulva intestinalis were three most influential species which contributed 27%, 21.9% and 18.5% variation of carbon fixation rate, respectively. Standing carbon stocks ranged from 7.52 gC/m2 to 41.31 gC/m2, and estimated carbon stocks varied from 11.77 gC/m2 to 96.49 gC/m2. The larger difference between estimated and standing carbon stocks implied that more fixed carbon was exported from the community in summer and autumn than in winter. This study suggested that intertidal macroalgal community could provide a potential function in carbon fixation of coastal ecosystem.

Pyropia species grow in the intertidal zone and are cold-water adapted. To date, most of the information about the whole plastid and mitochondrial genomes (ptDNA and mtDNA) of this genus is limited to Northern Hemisphere species. Here, we report the sequencing of the ptDNA and mtDNA of the Antarctic red alga Pyropia endiviifolia using the Illumina platform. The plastid genome (195 784 bp, 33.28% GC content) contains 210 protein-coding genes, 37 tRNA genes and 6 rRNA genes. The mitochondrial genome (34 603 bp, 30.5% GC content) contains 26 protein-coding genes, 25 tRNA genes and 2 rRNA genes. Our results suggest that the organellar genomes of Py. endiviifolia have a compact organization. Although the collinearity of these genomes is conserved compared with other Pyropia species, the genome sizes show significant differences, mainly because of the different copy numbers of rDNA operons in the ptDNA and group II introns in the mtDNA. The other Pyropia species have 2–3 distinct intronic ORFs in their cox 1 genes, but Py. endiviifolia has no introns in its cox 1 gene. This has led to a smaller mtDNA than in other Pyropia species. The phylogenetic relationships within Pyropia were examined using concatenated gene sets from most of the available organellar genomes with both the maximum likelihood and Bayesian methods. The analysis revealed a sister taxa affiliation between the Antarctic species Py. endiviifolia and the North American species Py. kanakaensis.

Bangiales is the only order of the Bangiophyceae and has been suggested to be monophyletic. This order contains approximately 190 species and is distributed worldwide. Previous molecular studies have produced robust phylogenies among the red algae, but the divergence times, historical biogeography and evolutionary rates of Bangiales have rarely been studied. Phylogenetic relationships within the Bangiales were examined using the concatenated gene sets from all available organellar genomes. This analysis has revealed the topology (((Bangia, Porphyra) Pyropia) Wildemania). Molecular dating indicates that Bangiales diversified approximately 246.40 million years ago (95% highest posterior density (HPD)=194.78–318.24 Ma, posterior probability (PP)=0.99) in the Late Permian and Early Triassic, and that the ancestral species most likely originated from eastern Gondwanaland (currently New Zealand and Australia) and subsequently began to spread and evolve worldwide. Based on pairwise comparisons, we found a slower rate of nucleotide substitutions and lower rates of diversification in Bangiales relative to Florideophyceae. Compared with Viridiplantae (green algae and land plants), the evolutionary rates of Bangiales and other Rhodophyte groups were found to be dramatically faster, by more than 3-fold for plastid genome (ptDNA) and 15-fold for mitochondrial genome (mtDNA). In addition, an average 2.5-fold lower dN/dS was found for the algae than for the land plants, which indicates purifying selection of the algae.

Changes in atmospheric CO2 concentration have played a central role in algal and plant adaptation and evolution. The commercially important red algal genus, Pyropia (Bangiales) appears to have responded to inorganic carbon (Ci) availability by evolving alternating heteromorphic generations that occupy distinct habitats. The leafy gametophyte inhabits the intertidal zone that undergoes frequent emersion, whereas the sporophyte conchocelis bores into mollusk shells. Here, we analyze a high-quality genome assembly of Pyropia yezoensis to elucidate the interplay between Ci availability and life cycle evolution. We find horizontal gene transfers from bacteria and expansion of gene families (e.g. carbonic anhydrase, anti-oxidative related genes), many of which show gametophyte-specific expression or significant up-regulation in gametophyte in response to dehydration. In conchocelis, the release of HCO3- from shell promoted by carbonic anhydrase provides a source of Ci. This hypothesis is supported by the incorporation of 13C isotope by conchocelis when co-cultured with 13C-labeled CaCO3., The nori producing seaweed Pyropia yezoensis has heteromorphic generations that occupy distinct habitats. Here, via genome assembly, transcriptome analysis, and 13 C isotope labeling, the authors show the interplay between inorganic carbon availability and life cycle evolution in the intertidal environment.

Pyropia yezoensis, one of the most economically important marine algae, suffers from the biotic stress of the oomycete necrotrophic pathogen Pythium porphyrae. However, little is known about the molecular defensive mechanisms employed by Pyr. yezoensis during the infection process. In the present study, we defined three stages of red rot disease based on histopathological features and photosynthetic physiology. Transcriptomic analysis was carried out at different stages of infection to identify the genes related to the innate immune system in Pyr. yezoensis. In total, 2139 up-regulated genes and 1672 down-regulated genes were identified from all the infected groups. Pathogen receptor genes, including three lectin genes (pattern recognition receptors (PRRs)) and five genes encoding typical plant R protein domains (leucine rich repeat (LRR), nucleotide binding site (NBS), or Toll/interleukin-1 receptor (TIR)), were found to be up-regulated after infection. Several defense mechanisms that were typically regarded as PAMP-triggered immunity (PTI) in plants were induced during the infection. These included defensive and protective enzymes, heat shock proteins, secondary metabolites, cellulase, and protease inhibitors. As a part of the effector-triggered immunity (ETI), the expression of genes related to the ubiquitin-proteasome system (UPS) and hypersensitive cell death response (HR) increased significantly during the infection. The current study suggests that, similar to plants, Pyr. yezoensis possesses a conserved innate immune system that counters the invasion of necrotrophic pathogen Pyt. porphyrae. However, the innate immunity genes of Pyr. yezoensis appear to be more ancient in origin compared to those in higher plants.

In this study, we present the complete plastid genome of Cryptophyceae sp. CCMP2293. The circular genome is 139,208 bp in length and contains 142 protein-coding genes (PCGs), 30 transfer RNA (tRNA) genes, 6 ribosome RNA (rRNA) genes, and 1 transfer-messenger RNA (tmRNA) gene. The overall nucleotide composition is: 33.6% A, 32.5% T, 16.8% C, and 17.1% G with a total A + T content of 66.1%. The phylogenetic tree was constructed to explore the taxonomic status of Cryptophyceae sp. CCMP2293, which is closely related to G. theta and R. salina.

This study investigated a new fungal disease that attacks Pyropia yezoensis, an economically important red alga that is extensively cultured in China. An incidence was found in a P. yezoensis farm during mid to end November 2012 at Haizhou Bay, Jiangshu Province, China. Histopathology revealed that the naturally infected thalli were overwhelmed by a fungus, leading to progressive red rot symptoms. The causative agent was isolated, grown in pure culture, and identified as a member of the genus Alternaria by morphology and sequence analysis of the nuclear ribosomal DNA containing the internal transcribed spacer (ITS) region of ITS1 and ITS2. In artificial infection experiments on P. yezoensis blades, the fungal isolate was able to cause the same characteristic histopathology seen in natural infections. This fungal isolate grew well at a wide range of temperatures (8–36 °C) and at low salinities (5–50 ‰). In an orthogonal test used to determine the effects of environmental factors (temperature, salinity, and conidia concentration) on disease expansion, it was found that higher temperatures and lower salinities easily caused red rot disease, with the optimal conditions for disease development being 23 °C, 24 ‰ salinity, and a conidia concentration of 105 mL−1. This is the first report to show that Alternaria causes red rot disease in P. yezoensis.

The dinoflagellate Alexandrium minutum is often associated with harmful algal blooms (HABs). This species consists of many strains that differ in their ability to produce toxins but have similar morphology, making identification difficult. In this study, species-specific rRNA probes were designed for whole-cell fluorescence in situ hybridization (FISH) to distinguish A. minutum from two phylogenetic clades. We acquired the complete SSU to LSU rDNA sequences (GenBank accession numbers JF906989-JF906999) of 11 Alexandrium strains and used these to design rRNA targeted oligonucleotide probes. Three ribotype-specific probes, M-GC-1, M-PC-2, and M-PC-3, were designed. The former is specific for the GC clade ("Global clade") of A. minutum, the majority of which have been found non-toxic, and the latter two are specific for the PSP (paralytic shellfish poisoning)-producing PC clade ("Pacific clade"). The specificity of these three probes was confirmed by FISH. All cells in observed fields of view were fluorescently labeled when probes and target species were incubated under optimized FISH conditions. However, the accessibility of rRNA molecules in ribosomes varied among the probe binding positions. Thus, there was variation in the distribution of positive signals in labeled cells within nucleolus and cytosol (M-GC-1, M-PC-3), or just nucleolus (M-PC-2). Our results provide a methodological basis for studying the biogeography and population dynamics of A. minutum, and providing an early warning of toxic HABs.

Previous studies found intraspecific diversity in Scrippsiella trochoidea A. R. Loeblich III, a widely distributed calcareous cyst-producing dinoflagellate. In this study, three strains (ST-1, ST-D6 and ST-K) of S. trochoidea isolated from the East Asian waters were studied, together with other geographical strains, to resolve their phylogenetic relationships. For the three East Asian isolates, two highly diverse regions of nuclear-encoded ribosomal DNA (rDNA), the 5.8S rDNA and its flanking internal transcribed spacers 1 and 2, and the 5′ portion of the large-subunit rDNA (encompassing the “D1“ and “D2” domains) were sequenced. Homologous sequences from other geographical isolates were selected from the GenBank database and the phylogenetic relationships were inferred from the molecular data of these strains. Strains of S. trochoidea were found to cluster into three major clades (STR1, STR2 and STR3), as reported in previous studies. Two of the three strains ST-1 and ST-K, were grouped in clade STR2, the other strain, ST-D6, belonged to clade STR3. The intraspecific diversity of S. trochoidea in East Asian waters makes it necessary to carry out phylogenetic investigations in combination with data of biogeography, population dynamics, and life cycle on the ecophysiology of a region.

Green tides have occurred in the Yellow Sea, China, every year from 2007 to 2015. The free-floating Ulva prolifera (Muller) J. Agardh was the causative macroalgal species. The co-occurring, attached U. intestinalis was also observed. Photosynthetic capacities were determined using chlorophyll fluorescence in situ and after 7 days lab acclimation, and a significant differences were noted. Pigment composition showed no obvious differences, but concentrations varied significantly, especially chlorophyll b in U. prolifera two times increase was observed after acclimation. The optimal photochemical efficiency of PS II (Fv/Fm) was significantly higher in U. prolifera. Photosynthetic rate (α), maximum relative electron transport rate (rETRmax), and minimum saturating irradiance (Ek), obtained from rapid light response curves (RLCs), showed almost the same photosynthetic physiological status as Fv/Fm. Quenching coefficients and low temperature (77 K) chlorophyll fluorescence emission spectra of thylakoid membranes analysis showed U. prolifera has a better recovery activity and plasticity of PSII than U. intestinalis. Furthermore, energy dissipation via non-photochemical quenching (NPQ) and state transitions showed efficacious photoprotection solution especially in U. prolifera suffered from the severe stresses. Results in the present study suggested that U. prolifera’s higher photosynthetic capacity would contribute to its free-floating proliferation, and efficacious photoprotection in addition to favorable oceanographic conditions and high nutrient levels support its growth and aggregation.

A method based on protein phosphatase enzyme activity inhibition for the detection of diarrhetic shellfish poison (DSP) was used to analyze the DSP toxicity in three oyster samples. Based on the standard dose-effect curve developed with a series of okadaic acid (OA) standard solutions, the DSP toxicity of the three oyster samples collected were screened, and the results showed that there were no OA and dinophysis toxins ( DTXs) in the samples without hydrolization. However, the OA toxicity could be detected in two of the hydrolyzed samples, and the OA toxicity of the two samples were 1.81 and 1.21 mu g OA eq./kg oyster, respectively.

A novel synthetic strategy has been developed for the fabrication of mesostructured titanosilicate with very high titanium content. By the combination of ultrasound radiation and a separate hydrolysis procedure, highly ordered MCM-41 titanosilicates can be synthesized within 3 h from gels with Ti/Si ratios up to 1. The physicochemical properties of the materials were characterized by means of XRD, TEM, FT-IR, UV-Vis DRS, 2 9 Si MAS NMR, and liquid nitrogen adsorption-desorption measurements. The results suggested that during crystallization, sonication re-dispersed and accelerated the condensation of inorganic species, and resulted in more condensed pore walls compared to those synthesized with the conventional methods. The presence of silica and ultrasound radiation remarkably suppressed the aggregation of titanium species, thus, at the medium titanium level, a relatively homogeneous dispersion of titanium within the MCM-41 framework was attained.

Ag-TiO2, Cu-TiO2 and Ni-TiO2 were prepared by sonication. The interactions of Ti-gel with silver, copper and nickel ions under ultrasound irradiation are very different, although these ions can be dispersed very well in titania. The results of EDXA and XRD analysis indicate that Ti-gel does not react with AgCl and crystallizes unaffectedly to form rutile. M(OH)2 (M = Cu and Ni), on the other hand, favors polycondensation with Ti-gel and affects the crystallization of Ti-gel. CuO favors stabilization of the anatase phase. Ni2+ ions tend to incorporate more easily into titania than Cu2+ ions do when the samples are calcined. TEM, and BET were also used to characterize the samples.

Sonication is used to prepare binary oxide Fe x O y –TiO 2 . Under sonication, the reaction of FeCl 3 with ( i -C 3 H 7 O) 4 Ti takes place successfully. The products are characterized by XRD, Mossbauer, Magnetic, DSC, TEM, SEM, and BET measurements. The results of characterization show that iron oxides in as-prepared samples are all amorphous and that the particles are nanometric. The product of the nonhydrolytic reaction remains amorphous at 773 K, and at higher temperatures the iron ions exist in the form of Fe 2 TiO 5 . The mesopores can withstand calcination of 773 K.

A novel method for shortening the synthesis time of mesoporous TiO2 to 6 h is reported. Low-angle XRD and TEM showed that mesoporous TiO2 with short-range ordered structures was synthesized when octadecylamine was used as a structure-directing agent and when Ti(OPri)4 was used as a precursor. The highest surface area (853 m2 g−1) was obtained after extraction with a dilute solution of nitric acid. The material maintained a high surface area (467 m2 g−1) after calcination at 350 °C, but the short-range ordered structures collapsed. XPS showed the interaction between TiO2 and octadecylamine, while DSC, TGA, and FT-IR spectra showed the removal of octadecylamine by extraction and calcination. A mechanism for the fast formation of mesoporous TiO2 is proposed. It is attributed to the formation of mesoporous material at high temperatures formed in the interface between the gas and bulk solutions resulting from ultrasound irradiation. Electrodes made from the mesoporous TiO2 were tested in a dye-sensitized solar cell. The short-circuit photocurrent, open-circuit photovoltage and fill factor increased with an increase in the sintering temperature, having a performance threshold at 450 °C, showing that the more ordered structures are required for high solar cell conversion efficiencies.

Iron-filled carbon nanostructures have been synthesized via a simple catalytic process, using Fe(CO)5 as the source of both iron and carbon. The iron-containing materials can be separated from the products using a permanent magnet. The nanotubes have dimensions of several hundred nanometers in length and 10–20 nm in width. The fabrication of cup-like and centipede-like carbon nanostructures is reported for the first time. In addition, some large fractured carbon cages with an average diameter of 200 nm were also observed in the products. XRD measurements revealed that the encapsulated iron nanoparticles had a bcc structure. The magnetic properties of the products were evaluated by conducting dc magnetic measurements. XPS and TGA were also employed to characterize the products.

The complete mitochondrial DNA of pennate diatom Fistulifera solaris was determined. The circular mitochondrial genome is 39 648 bp in length with 28.1% GC content and contains 63 genes, including 33 protein-coding genes, three conserved open reading frame (ORF154, ORF192 and ORF251), 25 tRNA and 2 rRNA genes. All protein-coding genes have AUG as start codon. A group I intron was found in nad11 gene. Both the gene content and the structure of Fistulifera solaris mitochondrial genome are very similar to Berkeleya fennica mitogenome (KM886611). Phylogeny analysis indicate F. solaris a close genetic relationship with Berkeleya fennica. This new mitogenome will provide more useful information for exploration in diatoms diversity and evolution.

The complete chloroplast sequence of Cryptophyceae algae Guillardia theta strain CCMP2712 was determined in this study. The genome consists of 138 455 bp containing a pair of rRNA-coding invert repeats of 4973 bp. The overall GC contents of the chloroplast genome were 32.9%. A total of 159 functional genes were annotated, which included 124 protein-coding genes, 30 tRNAs, 1tmRNA and 4 rRNA genes. Short intergenic regions, no introns and some overlapping genes make this cp genome compact. Phylogenetic analysis with the related algae cp genomes revealed that G. theta strain CCMP2712 a typical Cryptophyta algae and had a close genetic relationship with Rhodomonas salina (EF508371) and another previously reported G. theta (AF041468).

Ultrasound radiation can be used to synthesize a variety of mesporous materials. The reaction time is considerably shorter than the conventional methods. Ultrasonic waves can be further used for the insertion of amorphous nanosized catalysts into the mesopores. A detailed study demonstrates that the nanoparticles are deposited as a monolayer on the inner mesopores walls without blocking them. When the ultrasonically prepared catalyst/mesoporous-subtrate composite is used in catalysis a high conversion into product is obtained.

A liquid chromatography-mass spectrometry (LC-MS/MS) method using hydrophilic interaction liquid chromatography (HILIC) was developed for the analysis of neurotoxins β-N-methylamino-L-alanine (BMAA) and 2,4-diaminobutyric acid (DAB), using multiple reaction monitoring (MRM) scan mode. Oasis-MCX and Strata-X-C polymeric cation-exchange cartridges were used to clean extracts of cyanobacterial cultures, including two strains of Microcystis aeruginosa and one strain of Nostoc sp. The performance of the solid-phase extraction (SPE) cartridges for BMAA and DAB were evaluated using mixed standards and spiked cyanobacterial extracts, which demonstrated recoveries of BMAA and DAB ranging from 66% to 91%. Matrix effects in LC-MS/MS were evaluated, and while there was no effect on BMAA quantitation, suppression of DAB was found. Full scan (Q1) and enhanced product ion (EPI) monitoring showed that the DAB suppression may be due to closely eluting compounds, including lysine, histidine, arginine and three other compounds with [M + H](+) m/z of 88, 164 and 191. The procedures developed allow the sensitive and effective analysis of trace BMAA and DAB levels in cyanobacteria. While DAB was confirmed to be present, no BMAA was found in the cyanobacterial samples tested in the present study.

A simple and efficient methodology has been established for the selective synthesis of anatase and rutile as well as their mixtures with various precursors using ultrasound irradiation; the products, the particle sizes of which are nanometric (

High quality MCM-41 silica with thick walls and a very narrow distribution of mesopore size has been synthesized in a relatively short time via ultrasound radiation.

The catalytic reaction of Co(CO)3NO and Mg at 900 °C has led to the formation of multi-walled carbon nanoflasks.

Ultrasound radiation can be used to synthesize a variety of mesporous materials. The reaction time is considerably shorter than the conventional methods. Ultrasonic waves can be further used for the insertion of amorphous nanosized catalysts into the mesopores. A detailed study demonstrates that the nanoparticles are deposited as a monolayer on the inner mesopores walls without blocking them. When the ultrasonically prepared catalyst/mesoporous-subtrate composite is used in catalysis a high conversion into product is obtained.