Carotenogensis: A Historical Event of Primary to Secondary Adaptations to Earth's Oxygenation.

(1) Background: Oxygen has exerted a great effect in shaping the environment and driving biological diversity in Earth's history. Green lineage has evolved primary and secondary carotenoid biosynthetic systems to adapt to Earth's oxygenation, e.g.

Development and validation of single-step microwave-assisted digestion method for determining heavy metals in aquatic products: Health risk assessment.

A simple, rapid, and environmentally friendly microwave-assisted digestion method was developed and validated to determine heavy metals in aquatic products. The method could digest 640 samples using only one microwave digester in an 8 h working day. Only 2 mL of nitric acid was required to completely digest 0.

Identification of a RelA/SpoT Homolog and Its Possible Role in the Accumulation of Astaxanthin in .

A RelA/SpoT homolog, HpRSH, was identified in . HpRSH was found to catalyze Mg-dependent guanosine tetraphosphate (ppGpp) synthesis and Mn-dependent ppGpp hydrolysis, respectively. The transcription of HpRSH was significantly upregulated by environmental stresses, such as darkness, high light, nitrogen limitation, and salinity stress.

An improved method for sensitive quantification of isoprenoid diphosphates in the astaxanthin-accumulating Haematococcus pluvialis.

A sensitive method has been established to simultaneously determine the concentrations of isopentenyl pyrophosphate (IPP), geranyl diphosphate (GPP), farnesyl diphosphate (FPP) and geranylgeranyl diphosphate (GGPP) in H. pluvialis under different environments. This method increased the extraction efficiency of isoprenoid diphosphates through releasing isoprenoid diphosphates using Tissue Lyser.

Stringent Response Regulates Stress Resistance in Cyanobacterium .

Cyanobacterial blooms are serious environmental issues in global freshwater ecosystems. Nitrogen limitation is one of the most important strategies to control cyanobacterial blooms. However, recent researches showed that N limitation does not effectively control the bloom; oppositely, N limitation induces N-fixing cyanobacterial blooms.

Temporal heterogeneity of microbial communities and metabolic activities during a natural algal bloom.

Elucidating the interactions between algae and associated microbial communities is critical for understanding the mechanisms that mediate the dynamic of harmful algal blooms (HABs) in marine environment. However, the microbial functional profiles and their biogeochemical potential in HABs process remains elusive, especially during a complete natural HAB cycle. Here, we used pyrosequencing and functional gene array (GeoChip) to investigate microbial community dynamics and metabolic potential during a natural dinoflagellate (Noctiluca scintillans) bloom.

Optimization of extraction solvents, solid phase extraction and decoupling for quantitation of free isoprenoid diphosphates in Haematococcus pluvialis by liquid chromatography with tandem mass spectrometry.

Isoprenoid diphosphates are important precursors actively participating in many downstream metabolisms; they are often in modified forms, e.g., protein-coupled or esterified form.

Antibiofilm activity substances derived from coral symbiotic bacterial extract inhibit biofouling by the model strain Pseudomonas aeruginosa PAO1.

The mitigation of biofouling has received significant research attention, with particular focus on non-toxic and sustainable strategies. Here, we investigated quorum sensing inhibitor (QSI) bacteria as a means of controlling biofouling in a laboratory-scale system. Approximately, 200 strains were isolated from coral (Pocillopora damicornis) and screened for their ability to inhibit quorum sensing (QS).

A rapid UHPLC-HILIC method for algal guanosine 5'-diphosphate 3'-diphosphate (ppGpp) and the potential separation mechanism.

A fast and facile hydrophilic interaction liquid chromatography (HILIC) method was developed and applied to quantify physiologically important ppGpp and its analogues in a tough sample, the astaxanthin-accumulating alga Hameatococcus pluvialis. The method is able to analyze simultaneously seven nucleotides, including ppGpp at the order of pmol g cells within 12 min. Mechanism on the elution order was investigated.

A Novel Hydrolytic Activity of Tri-Functional Geranylgeranyl Pyrophosphate Synthase in Haematococcus pluvialis.

Under environmental stresses, Haematococcus pluvialis accumulates large amounts of carotenoids. Scale of carotenoid biosynthesis depends on availability of geranylgeranyl pyrophosphate (GGPP) precursor, which is supplied by GGPP synthase (GGPPS) through sequential 1'-4 condensation of three isopentenyl pyrophosphates (IPPs) into dimethylallyl pyrophosphate (DMAPP). Using IPP and DMAPP as substrates, a tri-functional HpGGPPS was identified in this study to promiscuously synthesize allylic prenyl pyrophosphates (PPPs), e.

Distribution Patterns of Microbial Community Structure Along a 7000-Mile Latitudinal Transect from the Mediterranean Sea Across the Atlantic Ocean to the Brazilian Coastal Sea.

A central goal in marine microecology is to understand the ecological factors shaping spatiotemporal microbial patterns and the underlying processes. We hypothesized that abiotic and/or biotic interactions are probably more important for explaining the distribution patterns of marine bacterioplankton than environmental filtering. In this study, surface seawater samples were collected about 7000 miles from the Mediterranean Sea, transecting the North Atlantic Ocean, to the Brazilian marginal sea.

Simultaneous determination of 13 carotenoids by a simple C18 column-based ultra-high-pressure liquid chromatography method for carotenoid profiling in the astaxanthin-accumulating Haematococcus pluvialis.

A simple ultra-high-pressure liquid chromatography (UHPLC) method for rapidly and simultaneously identifying thirteen carotenoids in Haematococcus pluvialis was developed in this study. The method is capable of effectively separating two astaxanthin isomers, two ζ-carotene isomers, and three phytoene isomers on two simple C18 columns within 9 and 12min only by using methanol and acetonitrile, respectively. To our best knowledge, this is the rapidest method for these carotenoid isomers, currently.

Draft Genome Sequence of Providencia sneebia Strain ST1, a Quorum Sensing Bacterium Associated with Marine Microalgae.

Providencia sneebia strain ST1 is a symbiotic bacterium (belonging to phylum gammaproteobacteria) with marine microalgae. This bacterium exhibits the ability to produce N-Acyl homoserine lactone signal molecule. To date, no genome that originates from marine Providencia spp.

Genome sequence of Enterobacter sp. ST3, a quorum sensing bacterium associated with marine dinoflagellate.

Phycosphere environment is a typical marine niche, harbor diverse populations of microorganisms, which are thought to play a critical role in algae host and influence mutualistic and competitive interactions. Understanding quorum sensing-based acyl-homoserine lactone (AHL) language may shed light on the interaction between algal-associated microbial communities in the native environment. In this work, we isolated an epidermal bacterium (was tentatively named Enterobacter sp.

Characterization and expression patterns of nitrate reductase from Dunaliella bardawil under osmotic stress and dilution shock.

A complementary DNA (cDNA) of nitrate reductase (NR) from Dunaliella bardawil was isolated using RT-PCR and RACEs techniques. The full-length D. bardawil NR (DbNR) cDNA is 3,107 bp containing a putative open reading frame of 2,670 bp in length which encodes 889 amino acids with a calculated molecular weight (MW) of 98.

Hypoosmotic expression of Dunaliella bardawil ζ-carotene desaturase is attributed to a hypoosmolarity-responsive element different from other key carotenogenic genes.

Some key carotenogenic genes (crts) in Dunaliella bardawil are regulated in response to salt stress partly due to salt-inducible cis-acting elements in their promoters. Thus, we isolated and compared the ζ-carotene desaturase (Dbzds) promoter with other crts promoters including phytoene synthase (Dbpsy), phytoene desaturase (Dbpds), and lycopene β-cyclase1 (DblycB1) to identify salt-inducible element(s) in the Dbzds promoter. In silico analysis of the Dbzds promoter found several potential cis-acting elements, such as abscisic acid response element-like sequence, myelocytomatosis oncogene1 recognition motif, AGC box, anaerobic motif2, and activation sequence factor1 binding site.

Six regulatory elements lying in the promoter region imply the functional diversity of chloroplast GAPDH in Duanliella bardawil.

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a well-known proverbial protein involved in various functions in vivo. The functional diversity of GAPDH from Dunaliella bardawil (DbGAPDH) may relate to the regulatory elements lying in the promoter at the transcriptional level. Using RT-PCR and RACE reactions, gapdh cDNA was isolated, and the full-length genomic sequence was obtained by LA-PCR-based genome walking.

In silico analysis of phytoene synthase and its promoter reveals hints for regulation mechanisms of carotenogenesis in Duanliella bardawil.

Motivation: Previous researches showed that phytoene synthase (Psy) from Dunaliella bardawil is the first regulatory point in carotenogenesis. We hypothesize certain interactions between the environmental stress factors and the regulatory sequences of Psy in D.bardawil (DbPsy).

Effects of salinities on the gene expression of a (NAD+)-dependent glycerol-3-phosphate dehydrogenase in Dunaliella salina.

Glycerol-3-phosphate dehydrogenase (G3pdh) is a key enzyme in the pathway of glycerol synthesis, which converts dihydroxyacetone phosphate (DHAP) to glycerol-3-phosphate. In this study, the effects of salinity changes on variation of cell shape and single cell glycerol content of Dunaliella salina were observed, and the effects of salinity changes on the gene expressions of a (NAD+)-dependent G3pdh (EC1.1.

Application of metabonomic analytical techniques in the modernization and toxicology research of traditional Chinese medicine.

In the recent years, a wide range of metabonomic analytical techniques are widely used in the modern research of traditional Chinese medicine (TCM). At the same time, the international community has attached increasing importance to TCM toxicity problems. Thus, many studies have been implemented to investigate the toxicity mechanisms of TCM.