The Prokaryotic Microalga KNUA012 to Improve Aldehyde Decarbonylase Expression for Use as a Biological Resource.

The prokaryotic microalga KNUA012 isolated from a freshwater bloom sample from Lake Hapcheon, Hapcheon-gun, South Korea, was investigated for its potential as a biofuel feedstock. Microalgae produce straight-chain alkanes/alkenes from acyl carrier protein-linked fatty acyls via aldehyde decarbonylase (AD; EC 1.2.

The microbial communities (bacteria, algae, zooplankton, and fungi) improved biofloc technology including the nitrogen-related material cycle in farms.

Microbes are essential in biofloc technology for controlling nitrogen levels in water. The composition and function of microorganisms with biofloc systems were reported; however, data on microorganisms other than bacteria, such as algae (which are essential in the nitrogen cycle) and zooplankton (which are bacterial and algal predators), remain limited. The microbial communities (including bacteria, algae, zooplankton, and fungi) were investigated in shrimp farms using biofloc technology.

Over-Expression of Dehydroascorbate Reductase Improves Salt Tolerance, Environmental Adaptability and Productivity in .

Abiotic stress induces reactive oxygen species (ROS) generation in plants, and high ROS levels can cause partial or severe oxidative damage to cellular components that regulate the redox status. Here, we developed salt-tolerant transgenic rice plants that overexpressed the dehydroascorbate reductase gene () under the control of a stress-inducible sweet potato promoter (). -expressing transgenic plants exhibited improved environmental adaptability compared to wild-type plants, owing to enhanced ascorbate levels, redox homeostasis, photosynthetic ability, and membrane stability through cross-activation of ascorbate-glutathione cycle enzymes under paddy-field conditions, which enhanced various agronomic traits, including root development, panicle number, spikelet number per panicle, and total grain yield.

Environmental Factors Associated with the Eukaryotic Microbial Community and Microalgal Groups in the Mountain Marshes of South Korea.

The diversity indices of eukaryotic microalgal groups in the Jeonglyeongchi, Waegok, and Wangdeungjae marshes of Mount Jiri, Korea, were measured using Illumina MiSeq and culture-based analyses. Waegok marsh had the highest species richness, with a Chao1 value of 828.00, and the highest levels of species diversity, with Shannon and Simpson index values of 6.

Effects of Co-culture on Improved Productivity and Bioresource for Microalgal Biomass Using the Floc-Forming Bacteria .

Bacterial and algal floc formation was induced by inoculating three species of wastewater-derived bacteria (, and ) into algal cultures (). Bacterial and algal flocs formed in algal cultures inoculated with and , and these flocs showed higher sedimentation rates than pure algal culture. The floc formed by (4988.

Enhanced glutathione content improves lateral root development and grain yield in rice plants.

Enhanced glutathione content improves lateral root development by positively regulating the transcripts of root development genes responsive to glutathione treatment, thereby increasing the overall productivity of rice plants. Glutathione is primarily known as a cellular antioxidant molecule, but its role in lateral root development in rice plants has not been elucidated. Here, we have investigated its role in lateral root development of rice Oryza sativa L.

Expression of Heterologous Gene Improves Glutathione (GSH)-Dependent Antioxidant System and Maintenance of Cellular Redox Status in PCC 7942.

An excess of reactive oxygen species (ROS) can cause severe oxidative damage to cellular components in photosynthetic cells. Antioxidant systems, such as the glutathione (GSH) pools, regulate redox status in cells to guard against such damage. Dehydroascorbate reductase (DHAR, EC 1.

Enhances Environmental Stress Tolerance and Improves Grain Yield by Modulating Stomatal Closure in Rice.

Abscisic acid-, stress-, and ripening-induced () genes are involved in responding to abiotic stresses, but their precise roles in enhancing grain yield under stress conditions remain to be determined. We cloned a rice () gene, , and characterized its function in rice plants. expression was induced by abscisic acid (ABA), salt, and drought treatments.

Illumina MiSeq Analysis and Comparison of Freshwater Microalgal Communities on Ulleungdo and Dokdo Islands.

Ulleungdo and Dokdo are volcanic islands with an oceanic climate located off the eastern coast of South Korea. In the present study, we used barcoded Illumina MiSeq to analyze eukaryotic microalgal genera collected from Seonginbong, the highest peak on Ulleungdo, and from groundwater sites on Dongdo and Seodo Islands, which are part of Dokdo. Species richness was significantly greater in the Seonginbong samples than in the Dongdo and Seodo samples, with 834 operational taxonomic units (OTUs) identified from Seonginbong compared with 203 OTUs and 182 OTUs from Dongdo and Seodo, respectively.

Expression of Gene Improves Cellular Redox Homeostasis and Photosynthesis Efficiency in PCC 7942.

Cyanobacterial 2-Cys peroxiredoxin (thioredoxin peroxidase, ) comprises a family of thiol antioxidant enzymes critically involved in cell survival under oxidative stress. In our previous study, a putative was identified using a proteomics analysis of rice ( L. , ) seedlings exposed to oxidative stress.

Improved stress tolerance and productivity in transgenic rice plants constitutively expressing the Oryza sativa glutathione synthetase OsGS under paddy field conditions.

Reactive oxygen species, which increase under various environmental stresses, have deleterious effects on plants. An important antioxidant, glutathione, is used to detoxify reactive oxygen species in plant cells and is mainly produced by two enzymes: gamma-glutamylcysteine synthetase (γ-ECS) and glutathione synthetase (GS). To evaluate the functional roles of the glutathione synthetase gene (OsGS) in rice, we generated four independent transgenic rice plants (TG1-TG4) that overexpressed OsGS under the control of the constitutively expressed OsCc1 promoter.

Structure and catalytic mechanism of monodehydroascorbate reductase, MDHAR, from Oryza sativa L. japonica.

Ascorbic acid (AsA) maintains redox homeostasis by scavenging reactive oxygen species from prokaryotes to eukaryotes, especially plants. The enzyme monodehydroascorbate reductase (MDHAR) regenerates AsA by catalysing the reduction of monodehydroascorbate, using NADH or NADPH as an electron donor. The detailed recycling mechanism of MDHAR remains unclear due to lack of structural information.

Potential Application of the Oryza sativa Monodehydroascorbate Reductase Gene (OsMDHAR) to Improve the Stress Tolerance and Fermentative Capacity of Saccharomyces cerevisiae.

Monodehydroascorbate reductase (MDHAR; EC 1.6.5.

Crystal structures of aldehyde deformylating oxygenase from Limnothrix sp. KNUA012 and Oscillatoria sp. KNUA011.

The cyanobacterial aldehyde deformylating oxygenase (cADO) is a key enzyme that catalyzes the unusual deformylation of aliphatic aldehydes for alkane biosynthesis and can be applied to the production of biofuel in vitro and in vivo. In this study, we determined crystal structures of two ADOs from Limnothrix sp. KNUA012 (LiADO) and Oscillatoria sp.

Structural understanding of the recycling of oxidized ascorbate by dehydroascorbate reductase (OsDHAR) from Oryza sativa L. japonica.

Dehydroascorbate reductase (DHAR) is a key enzyme involved in the recycling of ascorbate, which catalyses the glutathione (GSH)-dependent reduction of oxidized ascorbate (dehydroascorbate, DHA). As a result, DHAR regenerates a pool of reduced ascorbate and detoxifies reactive oxygen species (ROS). In previous experiments involving transgenic rice, we observed that overexpression of DHAR enhanced grain yield and biomass.

Purification, characterization and preliminary X-ray crystallographic studies of monodehydroascorbate reductase from Oryza sativa L. japonica.

Monodehydroascorbate reductase (MDHAR; EC 1.6.5.

Crystallization and preliminary X-ray crystallographic studies of dehydroascorbate reductase (DHAR) from Oryza sativa L. japonica.

Dehydroascorbate reductase from Oryza sativa L. japonica (OsDHAR), a key enzyme in the regeneration of vitamin C, maintains reduced pools of ascorbic acid to detoxify reactive oxygen species. In previous studies, the overexpression of OsDHAR in transgenic rice increased grain yield and biomass as well as the amount of ascorbate, suggesting that ascorbate levels are directly associated with crop production in rice.

Homologous expression of cytosolic dehydroascorbate reductase increases grain yield and biomass under paddy field conditions in transgenic rice (Oryza sativa L. japonica).

Dehydroascorbate reductase (DHAR, EC 1.8.5.

Saccharomyces cerevisiae KNU5377 stress response during high-temperature ethanol fermentation.

Fuel ethanol production is far more costly to produce than fossil fuels. There are a number of approaches to cost-effective fuel ethanol production from biomass. We characterized stress response of thermotolerant Saccharomyces cerevisiae KNU5377 during glucose-based batch fermentation at high temperature (40°C).