Inhibition of Polyphosphate Degradation in sp. PCC6803 through Inactivation of the Gene.

Phosphorus is an essential but non-renewable nutrient resource critical for agriculture. Luxury phosphorus uptake allows microalgae to synthesize polyphosphate and accumulate phosphorus, but, depending on the strain of algae, polyphosphate may be degraded within 4 hours of accumulation. We studied the recovery of phosphorus from wastewater through luxury uptake by an engineered strain of sp.

Improvement of Lutein and Zeaxanthin Production in sp. 247 by Optimizing Light Intensity and Culture Salinity Conditions.

In this study, we sought to improve lutein and zeaxanthin production in sp. 247 and investigated the effect of environmental factors on lutein and zeaxanthin productivity in sp. The basic medium selection and N:P ratio were adjusted to maximize cell growth in one-stage culture, and lutein and zeaxanthin production conditions were optimized using a central composite design for two-stage culture.

Different Regulatory Modes of sp. PCC 6803 in Response to Photosynthesis Inhibitory Conditions.

Cyanobacteria are promising industrial platforms owing to their ability to produce diverse natural secondary metabolites and nonnative value-added biochemicals from CO and light. To fully utilize their industrial potency, it is critical to understand their photosynthetic efficiency under various environmental conditions. In this study, we elucidated the inhibitory mechanisms of photosynthesis under high-light and low-temperature stress conditions in the model cyanobacterium sp.

Multi-Omic Analyses Reveal Habitat Adaptation of Marine Cyanobacterium sp. PCC 7338.

Cyanobacteria are considered as promising microbial cell factories producing a wide array of bio-products. Among them, sp. PCC 7338 has the advantage of growing in seawater, rather than requiring arable land or freshwater.

Enhanced lipid productivity in AGP knockout marine microalga Tetraselmis sp. using a DNA-free CRISPR-Cas9 RNP method.

A marine green microalga, Tetraselmis sp., has been studied for the production of biomass and lipids in seawater culture. Since carbohydrate and lipid biosynthesis are competitive metabolic pathways, we attempted to increase lipid synthesis in Tetraselmis by inhibiting carbohydrate synthesis.

Isolation and genome analysis of Winogradskyella algicola sp. nov., the dominant bacterial species associated with the green alga Dunaliella tertiolecta.

Microalgae and bacteria are known to be closely associated in diverse environments. To isolate dominant bacterial species associated with a green alga, Dunaliella tertiolecta, a photoreactor culture of the microalga was investigated using culture-based and culture-independent approaches. The bacterial community structure of the algal culture showed that the most abundant bacterial species under the culture conditions was related to the genus Winogradskyella.

Phycobiliproteins Production Enhancement and Lipidomic Alteration by Titanium Dioxide Nanoparticles in Synechocystis sp. PCC 6803 Culture.

This study aimed to improve the production of phycobiliproteins using TiO nanoparticles (NPs) in Synechocystis sp. PCC 6803. The growth characteristics of Synechocystis cells were not affected by TiO NPs treatment, but this treatment increased the chlorophyll content significantly by 62.

Label-free non-invasive quantitative measurement of lipid contents in individual microalgal cells using refractive index tomography.

Microalgae are promising candidates for biofuel production due to their high lipid content. To facilitate utilization of the microalgae for biofuel, rapid quantification of the lipid contents in microalgae is necessary. However, conventional methods based on the chemical extraction of lipids require a time-consuming destructive extraction process.

Enhanced Production of Fatty Acids via Redirection of Carbon Flux in Marine Microalga sp.

Lipids in microalgae are energy-rich compounds and considered as an attractive feedstock for biodiesel production. To redirect carbon flux from competing pathways to the fatty acid synthesis pathway of sp., we used three types of chemical inhibitors that can block the starch synthesis pathway or photorespiration, under nitrogen-sufficient and nitrogen-deficient conditions.

Genome-wide transcriptome analysis revealed organelle specific responses to temperature variations in algae.

Temperature is a critical environmental factor that affects microalgal growth. However, microalgal coping mechanisms for temperature variations are unclear. Here, we determined changes in transcriptome, total carbohydrate, total fatty acid methyl ester, and fatty acid composition of Tetraselmis sp.

Effect of Ethephon as an Ethylene-Releasing Compound on the Metabolic Profile of Chlorella vulgaris.

In this study, Chlorella vulgaris (C. vulgaris) was treated with ethephon at low (50 μM) and high (200 μM) concentrations in medium and harvested at 0, 7, and 14 days, respectively. The presence of ethephon led to significant metabolic changes in C.

Development of a floating photobioreactor with internal partitions for efficient utilization of ocean wave into improved mass transfer and algal culture mixing.

Culturing microalgae in the ocean has potentials that may reduce the production cost and provide an option for an economic biofuel production from microalgae. The ocean holds great potentials for mass microalgal cultivation with its high specific heat, mixing energy from waves, and large cultivable area. Suitable photobioreactors (PBRs) that are capable of integrating marine energy into the culture systems need to be developed for the successful ocean cultivation.

Elucidation of the growth delimitation of Dunaliella tertiolecta under nitrogen stress by integrating transcriptome and peptidome analysis.

Dunaliella tertiolecta LB 999 is an oleaginous microalgae species that produces large quantities of lipid and starch during nitrogen starvation; however, nitrogen starvation also limits the cell growth. In order to understand the underlying mechanisms of this phenomenon, the transcriptome and peptidome of D. tertiolecta LB 999 grown under different nitrogen and light conditions were analyzed.

Comparative lipidomic profiling of two Dunaliella tertiolecta strains with different growth temperatures under nitrate-deficient conditions.

The metabolic changes that occur in Dunaliella tertiolecta upon exposure to low temperatures and nitrate deficiency were analyzed by exploring the fatty acid composition and lipid profile of two strains that were acclimated to different temperatures. The results indicate that the levels of linolenic acid (C18:3) and diacylglyceryl-N,N,N-trimethylhomoserine (DGTS) were significantly higher in the low-temperature (15 °C) strain (SCCAP K-0591) than in a strain grown at 21 °C (UTEX LB999). In addition, DGTS accumulated in LB999 under nitrate-deficient conditions, while the levels of most lipids, including DGTS, remained almost consistent in K-0591.

Effects of light intensity and nitrogen starvation on glycerolipid, glycerophospholipid, and carotenoid composition in Dunaliella tertiolecta culture.

Time-course variation of lipid and carotenoid production under high light (300 μE/m²s) and nitrogen starvation conditions was determined in a Dunaliella tertiolecta strain. Nanoelectrospray (nanoESI) chip based direct infusion was used for lipid analysis and ultra-performance liquid chromatography (UPLC) coupled with a photodiode array (PDA) or atmospheric chemical ionization mass spectrometry (APCI-MS) was used for carotenoid analysis. A total of 29 lipids and 7 carotenoids were detected.

Carotenogenesis in Haematococcus lacustris: role of protein tyrosine phosphatases.

In the present study, we examined the inhibitory effects of protein tyrosine phosphatase (PTPase) inhibitors, including sodium orthovanadate (SOV), ammonium molybdate (AM), and iodoacetamide (IA), on cell growth, accumulation of astaxanthin, and PTPase activity in the photosynthetic algae Haematococcus lacustris. PTPase activity was assayed spectrophotometrically and was found to be inhibited 60% to 90% after treatment with the inhibitors. SOV markedly abolished PTPase activity, significantly activating the accumulation of astaxanthin.

Proteomics of proteins associated with astaxanthin accumulation in the green algae Haematococcus lacustris under the influence of sodium orthovanadate.

An extensive proteomics analysis has identified proteins associated with astaxanthin accumulation in the green algae Haematococcus lacustris under oxidative stress induced by sodium orthovanadate (SOV). Measurement of total carotenoid accumulation per cell biomass showed an increase from 81 to 136 pg/cell after being exposed to 2.5 mM SOV, when compared to the control cells at day 3 of cultivation.

Statistical optimization of the growth factors for Chaetoceros neogracile using fractional factorial design and central composite design.

Statistical experimental designs; involving (i) a fractional factorial design (FFD) and (ii) a central composite design (CCD) were applied to optimize the culture medium constituents for production of a unique antifreeze protein by the Antartic microalgae Chaetoceros neogracile. The results of the FFD suggested that NaCl, KCl, MgCl2, and Na2SiO3 were significant variables that highly influenced the growth rate and biomass production. The optimum culture medium for the production of an antifreeze protein from C.

Haematococcus pluvialis cell-mass sensing using ultraviolet fluorescence spectroscopy.

A simple whole-cell-based sensing system is proposed for determining the cell mass of H. pluvialis using ultraviolet fluorescence spectroscopy. An emission signal at 368 nm was used to detect the various kinds of green, green-brown, brown-red, and red H.