Seasonal changes of species- and guild-based benthic diatom communities in the transitional water zone of the Yellow River Delta.

Benthic diatoms serve as exemplary indicators for the assessment of ecological conditions in freshwater ecosystems. However, an approach to assessing and managing transitional water zones by benthic diatoms is relatively less. This study entailed a detailed analysis and comparison of the seasonal dynamics in species- and guild-based benthic diatom communities and their driving factors in a small-scale transitional water zone of the Yellow River Delta.

Enhancement of hemostatic properties of Cyclotella cryptica frustule through genetic manipulation.

Background: The silicified cell wall of diatoms, also known as frustule, shows huge potential as an outstanding bio-nanomaterial for hemostatic applications due to its high hemostatic efficiency, good biocompatibility, and ready availability. As the architectural features of the frustule determine its hemostatic performance, it is of great interest to develop an effective method to modify the frustule morphology into desired patterns to further improve hemostatic efficiency.

Results: In this study, the gene encoding Silicalemma Associated Protein 2 (a silicalemma-spanning protein) of Cyclotella cryptica (CcSAP2) was identified as a key gene in frustule morphogenesis.

UDP-glucose pyrophosphorylase as a target for regulating carbon flux distribution and antioxidant capacity in Phaeodactylum tricornutum.

UDP-glucose pyrophosphorylase (UGPase) is a key enzyme for polysaccharide synthesis, and its role in plants and bacteria is well established; however, its functions in unicellular microalgae remain ill-defined. Here, we perform bioinformatics, subcellular localization as well as in vitro and in vivo analyses to elucidate the functions of two UGPs (UGP1 and UGP2) in the model microalga Phaeodactylum tricornutum. Despite differences in amino acid sequence, substrate specificity, and subcellular localization between UGP1 and UGP2, both enzymes can efficiently increase the production of chrysolaminarin (Chrl) or lipids by regulating carbon flux distribution without impairing growth and photosynthesis in transgenic strains.

An attempt to simultaneously quantify the polysaccharide, total lipid, protein and pigment in single Cyclotella cryptica cell by Raman spectroscopy.

Background: At present, the conventional methods for determining photosynthetic products of microalgae are usually based on a large number of cell mass to reach the measurement baseline, and the result can only reveal the average state at the population level, which is not feasible for large-scale and rapid screening of specific phenotypes from a large number of potential microalgae mutants. In recent years, single-cell Raman spectra (SCRS) has been proved to be able to rapidly and simultaneously quantify the biochemical components of microalgae. However, this method has not been reported to analyze the biochemical components of Cyclotella cryptica (C.

Energy metabolism and intracellular pH regulation reveal different physiological acclimation mechanisms of Chlorella strains to high concentrations of CO.

The intolerance of high CO in the exhaust gas is the "bottleneck" limiting the wide application of microalgae for CO biosequestration. Around this topic, we selected high-CO-tolerant (LAMB 33 and 31) and nontolerant (LAMB 122) Chlorella strains to study their different energy metabolisms and cytoplasmic pH regulations in response to high CO. Under 40 % CO, LAMB 33 and 31 both showed elevated ATP synthesis, accelerated ATP consumption and fast cytoplasmic pH regulation while exhibiting different acclimating strategies therein: chloroplast acclimations were reflected by high chlorophyll contents in 33 but photosystem transitions in 31; faster mitochondrial acclimations occurred in 33 than in 31; cellular organic carbon mainly flowed to monosaccharide synthesis for 33 but to monosaccharide and protein synthesis for 31; and cytoplasmic pH regulation was attributed to V-ATPase in 31 but not in 33.

How do microalgae in response to biological pollution treat in cultivation? A case study investigating microalgal defense against ciliate predator Euplotes vannus.

Microalgae have significant amounts of proteins, lipids, carotenoids, vitamins, minerals, and unique pigments. However, with the gradual expansion of microalgae cultivation, hostile biological pollution seriously restricted the large-scale microalgae cultivation and limited the exploitation of its biological resources. Moreover, protozoan poses the greatest threat to microalgae cultivation.

A review on the progress, challenges and prospects in commercializing microalgal fucoxanthin.

Fucoxanthin, the most abundant but nearly untapped carotenoid resource, is in the spotlight in the last decade from various perspectives due to a wide range of bioactivities and healthy benefits. The exploitation of fucoxanthin for nutraceutical and pharmaceutical purposes encompasses enormous scientific and economic potentials. Traditional production of fucoxanthin from brown algae (macroalgae) is constrained by limited yield and prohibitively high cost.

Screening and application of Chlorella strains on biosequestration of the power plant exhaust gas evolutions of biomass growth and accumulation of toxic agents.

To use microalgae for the biosequestration of carbon dioxide (CO) emitted from the coal-fired power plants, the screening of high CO tolerant microalgae and their accumulation of toxic agents have attracted significant research attention. This study evaluated 10 Chlorella strains for high CO tolerance using combined growth rates and growth periods subjected to logistic parameters. We selected LAMB 31 with high r (0.

Potential to resist biological contamination in marine microalgae culture: Effect of extracellular substances of Nannochloropsis oceanica on population growth of Euplotes vannus and other protozoa.

The commercially important marine microalgae Nannochloropsis oceanica is easily ingested by protozoan predators during large-scale cultivation. However, investigations into the effect of microalgae on the growth of protozoa are scant. A feeding experiment was conducted with Euplotes vannus grazing on different concentrations of N.

Tentative identification of key factors determining the hemostatic efficiency of diatom frustule.

It is increasingly essential to develop excellent materials for rapid hemorrhage control. Our previous study showed that centric diatoms such as frustules were superior to QuikClot® in hemostasis, however, related studies in pennate diatoms are still scarce. The morphological and physicochemical properties of pennate diatoms are quite different from those of centric diatoms, meaning that significant differences may also be observed from their hemostatic effects.

Effects of fluctuating temperature in open raceway ponds on the biomass accumulation and harvest efficiency of Spirulina in large-scale cultivation.

It is of great significance to select strains with wide adaptability to temperature range for large-scale commercial cultivation of Spirulina. The aim of this study was to comprehend how the strain H-208 grew and whether this strain had any advantages in temperature adaptation compared with local production strain during the large-scale cultivation in Inner Mongolia. The results showed that the strain H-208 could adapt to the new environmental condition quickly, and the daily average biomass dry weight of strain H-208 was 49% and 52% more than that of production strain M-1 in first cycle (20.

The molecular mechanisms of Chlorella sp. responding to high CO: A study based on comparative transcriptome analysis between strains with high- and low-CO tolerance.

High CO acclimation for microalgae has attracted large research attention owing to the usefulness of microalgae in bio-sequestration of CO from the emission source. In this study, one high CO tolerant (LAMB 31) and non-tolerant (LAMB 122) Chlorella sp. strains were transferred from air to 40% CO, during which four time points were chosen for comparative transcriptome analysis.

The NanDeSyn database for Nannochloropsis systems and synthetic biology.

Nannochloropsis species, unicellular industrial oleaginous microalgae, are model organisms for microalgal systems and synthetic biology. To facilitate community-based annotation and mining of the rapidly accumulating functional genomics resources, we have initiated an international consortium and present a comprehensive multi-omics resource database named Nannochloropsis Design and Synthesis (NanDeSyn; http://nandesyn.single-cell.

Large-Scale Cultivation of for Biological CO Mitigation in Open Raceway Ponds Using Purified CO From a Coal Chemical Flue Gas.

In order to select excellent strains with high CO fixation capability on a large scale, nine species were cultivated in columnar photobioreactors with the addition of 10% CO. The two species selected (208 and 220) were optimized for pH value, total dissolved inorganic carbon (DIC), and phosphorus content with intermittent CO addition in 4 m indoor raceway ponds. On the basis of biomass accumulation and CO fixation rate in the present study, the optimum pH, DIC, and phosphate concentration were 9.

The regulating mechanisms of CO fixation and carbon allocations of two Chlorella sp. strains in response to high CO levels.

The extreme high CO in industrial exhaust gas cannot be tolerated by microalgae is the key challenge for the application of microalgae in CO bio-sequestration. To provide better insights for this challenge, we chose one high CO tolerant (Chlorella sp. LAMB 31) and non-tolerant (Chlorella sp.

Genome assembly of provides evidence of host nucleus overthrow by the symbiont nucleus during speciation.

The species of the genus are unique in their maintenance of a nucleus-plastid continuum throughout their cell cycle, non-motility and asexual reproduction. These characteristics should have been endorsed in their gene assemblages (genomes). Here we show that has a genome of 29.

Treating wastewater by indigenous microalgae strain in pilot platform located inside a municipal wastewater treatment plant.

Various resources from a municipal wastewater treatment plant (MWTP) are available for microalgae cultivation plants, suggesting that a combination of these technologies can be used to produce microalgae biomass and remove contaminants at a low cost. In this study, the growth performance and nutrient removal efficiency of an indigenous sp. in various wastewater media with different exchange patterns were investigated firstly, then transferred to a pilot-scale photobioreactor (located inside a MWTP) for bioremediation use.

Influence of the physicochemical characteristics of diatom frustules on hemorrhage control.

Uncontrollable hemorrhage is the main cause of death in military and civilian accidents. It is therefore necessary and an urgent requirement to develop a safe and efficient hemostatic material. In this study, the hemostatic performance of frustules of three centric diatom species (Thalassiosira weissflogii, Thalassiosira sp.

Two-step process: Enhanced strategy for wastewater treatment using microalgae.

Microalgae possess many advantages, but the lack of a suitable strategy to simultaneously facilitate their low cost cultivation and high value productions limits their commercial applications. In this study, two microalgae strains (RT_C and RT_F) isolated from a municipal wastewater treatment plant were used to establish a two-step wastewater treatment process. During step-1, RT_C was cultivated in composite wastewater due to its high tolerance of sludge centrate; followed by step-2, in which the supernatant generated from RT_C culture was used to cultivate RT_F.

The Role of Malic Enzyme on Promoting Total Lipid and Fatty Acid Production in .

To verify the function of malic enzyme (ME1), the ME1 gene was endogenously overexpressed in . Overexpression of increased neutral and total lipid content and significantly increased saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs) in transformants, which varied between 23.19 and 25.

Heterogeneity of intron presence/absence in Olifantiella sp. (Bacillariophyta) contributes to the understanding of intron loss.

Although hypotheses have been proposed and developed to interpret the origins and functions of introns, substantial controversies remain about the mechanism of intron evolution. The availability of introns in the intermediate state is quite helpful for resolving this debate. In this study, a new strain of diatom (denominated as DB21-1) was isolated and identified as Olifantiella sp.

Co-culturing bacteria and microalgae in organic carbon containing medium.

Background: Microalgae frequently grow in natural environment and long-term laboratory cultures in association with bacteria. Bacteria benefit the oxygen and extracellular substances generated by microalgae, and reimburse microalgae with carbon dioxide, vitamins and so on. Such synergistic relationship has aided in establishing an efficient microalga-bacterium co-culturing mode.

Silencing UDP-glucose pyrophosphorylase gene in Phaeodactylum tricornutum affects carbon allocation.

The effects of the suppression of UDP-glucose pyrophosphorylase (UGPase) on chrysolaminaran biosynthesis and carbon allocation were investigated in Phaeodactylum tricornutum. The 69% decrease in UGPase activity was accompanied by a 4.89 fold reduction in Ugp transcript abundance.

Large-scale biodiesel production using flue gas from coal-fired power plants with Nannochloropsis microalgal biomass in open raceway ponds.

The potential use of microalgal biomass as a biofuel source has raised broad interest. Highly effective and economically feasible biomass generating techniques are essential to realize such potential. Flue gas from coal-fired power plants may serve as an inexpensive carbon source for microalgal culture, and it may also facilitate improvement of the environment once the gas is fixed in biomass.