Optimal conditions of algal breeding using neutral beam and applying it to breed Euglena gracilis strains with improved lipid accumulation.

Microalgae are considered to be more useful and effective to use in biomass production than other photosynthesis organisms. However, microalgae need to be altered to acquire more desirable traits for the relevant purpose. Although neutron radiation is known to induce DNA mutations, there have been few studies on its application to microalgae, and the optimal relationship between irradiation intensity and mutation occurrence has not been established.

Regulatory Role of GgaR (YegW) for Glycogen Accumulation in K-12.

Glycogen, the stored form of glucose, accumulates upon growth arrest in the presence of an excess carbon source in and other bacteria. Chromatin immunoprecipitation screening for the binding site of a functionally unknown GntR family transcription factor, YegW, revealed that the operon was a single target of the genome. Although none of the genes in the operon have a clear function, a previous study suggested their involvement in the production of ADP-glucose (ADPG), a glycogen precursor.

Low-temperature and circadian signals are integrated by the sigma factor SIG5.

Chloroplasts are a common feature of plant cells and aspects of their metabolism, including photosynthesis, are influenced by low-temperature conditions. Chloroplasts contain a small circular genome that encodes essential components of the photosynthetic apparatus and chloroplast transcription/translation machinery. Here, we show that in Arabidopsis, a nuclear-encoded sigma factor that controls chloroplast transcription (SIGMA FACTOR5) contributes to adaptation to low-temperature conditions.

A distinct class of GTP-binding proteins mediates chloroplast protein import in Rhodophyta.

Chloroplast protein import is mediated by translocons named TOC and TIC on the outer and inner envelope membranes, respectively. Translocon constituents are conserved among green lineages, including plants and green algae. However, it remains unclear whether Rhodophyta (red algae) share common chloroplast protein import mechanisms with the green lineages.

Transcription Factor SrsR (YgfI) Is a Novel Regulator for the Stress-Response Genes in Stationary Phase in K-12.

Understanding the functional information of all genes and the biological mechanism based on the comprehensive genome regulation mechanism is an important task in life science. YgfI is an uncharacterized LysR family transcription factor in . To identify the function of YgfI, the genomic SELEX (gSELEX) screening was performed for YgfI regulation targets on the genome.

The Unicellular Red Alga , an Excellent Model Organism for Elucidating Fundamental Molecular Mechanisms and Their Applications in Biofuel Production.

Microalgae are considered one of the best resources for the production of biofuels and industrially important compounds. Various models have been developed to understand the fundamental mechanism underlying the accumulation of triacylglycerols (TAGs)/starch and to enhance its content in cells. Among various algae, the red alga has been considered an excellent model system to understand the fundamental mechanisms behind the accumulation of TAG/starch in the microalga, as it has a smaller genome size and various biotechnological methods are available for it.

Identification of Transcription Factors and the Regulatory Genes Involved in Triacylglycerol Accumulation in the Unicellular Red Alga .

Microalgal triacylglycerols (TAGs) are a good feedstock for liquid biofuel production. Improving the expression and/or function of transcription factors (TFs) involved in TAG accumulation may increase TAG content; however, information on microalgae is still lacking. In this study, 14 TFs in the unicellular red alga were identified as candidate TFs regulating TAG accumulation using available transcriptome and phosphoproteome data under conditions driving TAG accumulation.

Expanded roles of pyruvate-sensing PdhR in transcription regulation of the K-12 genome: fatty acid catabolism and cell motility.

The transcription factor PdhR has been recognized as the master regulator of the pyruvate catabolism pathway in , including both NAD-linked oxidative decarboxylation of pyruvate to acetyl-CoA by PDHc (pyruvate dehydrogenase complex) and respiratory electron transport of NADH to oxygen by Ndh-CyoABCD enzymes. To identify the whole set of regulatory targets under the control of pyruvate-sensing PdhR, we performed genomic SELEX (gSELEX) screening . A total of 35 PdhR-binding sites were identified along the K-12 genome, including previously identified targets.

Proteomic analysis of haem-binding protein from and .

Chloroplast biogenesis involves the coordinated expression of the plastid and nuclear genomes, requiring information to be sent from the nucleus to the developing chloroplasts and vice versa. Although it is well known how the nucleus controls chloroplast development, it is still poorly understood how the plastid communicates with the nucleus. Currently, haem is proposed as a plastid-to-nucleus (retrograde) signal that is involved in various physiological regulations, such as photosynthesis-associated nuclear genes expression and cell cycle in plants and algae.

Identification and analysis of a principal sigma factor interacting protein SinA, essential for growth at high temperatures in a cyanobacterium Synechococcus elongatus PCC 7942.

Proteins that bind to RNA polymerase (RNAP) sigma factors play important roles in various transcriptional regulations. In this study, we identified a candidate of the principal sigma factor interacting protein in cyanobacteria, named SinA, based on a previous comprehensive protein interaction study (Sato et al., 2007) and analyzed this in the cyanobacterium Synechococcus elongatus PCC 7942.

Multiple Modification of Chromosomal Loci Using Selection Marker in the Unicellular Red Alga .

The unicellular red alga has been used as a eukaryotic photosynthetic model for various basic and applied studies. Although the nuclear genome of can be modified by homologous recombination with exogenously introduced DNA, it has been difficult to modify multiple chromosome loci within the same strain because of the limited number of available positive selection markers. Recently, we reported a modified gene cassette (), which can be used repeatedly for nuclear genome transformation using the pMKT plasmid vectors for epitope tagging (3x FLAG- or 3x Myc-) of nuclear-encoded proteins.

Overexpression of a glycogenin, CmGLG2, enhances floridean starch accumulation in the red alga Cyanidioschyzon merolae.

Microalgae accumulate energy-reserved molecules, such as triacylglycerol and carbohydrates, which are suitable feedstocks for renewable energies such as biodiesel and bioethanol. However, the molecular mechanisms behind the microalgae accumulating these molecules require further elucidation. Recently, we have reported that the target of rapamycin (TOR)-signaling is a major pathway to regulate floridean starch synthesis by changing the phosphorylation status of CmGLG1, a glycogenin generally required for the initiation of starch/glycogen synthesis, in the unicellular red alga Cyanidioschyzon merolae.

Top Starch Plating Method for the Efficient Cultivation of Unicellular Red Alga .

The unicellular red alga has been used as a model photosynthetic eukaryote for various basic and applied studies, and several of these molecular genetics techniques have been reported. However, there are still improvements to be made concerning the plating method. The conventional plating method often generates diffuse colonies and single colonies cannot be easily isolated.

Target of rapamycin-signaling modulates starch accumulation via glycogenin phosphorylation status in the unicellular red alga Cyanidioschyzon merolae.

The target of rapamycin (TOR) signaling pathway is involved in starch accumulation in various eukaryotic organisms; however, the molecular mechanism behind this phenomenon in eukaryotes has not been elucidated. We report a regulatory mechanism of starch accumulation by TOR in the unicellular red alga, Cyanidioschyzon merolae. The starch content in C.

Accelerated triacylglycerol production without growth inhibition by overexpression of a glycerol-3-phosphate acyltransferase in the unicellular red alga Cyanidioschyzon merolae.

Microalgae accumulate triacylglycerols (TAGs), a promising feedstock for biodiesel production, under unfavorable environmental or stress conditions for their growth. Our previous analyses revealed that only transcripts of CmGPAT1 and CmGPAT2, both encoding glycerol-3-phosphate acyltransferase, were increased among fatty acid and TAG synthesis genes under TAG accumulation conditions in the red alga Cyanidioschyzon merolae. In this study, to investigate the role of these proteins in TAG accumulation in C.

The checkpoint kinase TOR (target of rapamycin) regulates expression of a nuclear-encoded chloroplast RelA-SpoT homolog (RSH) and modulates chloroplast ribosomal RNA synthesis in a unicellular red alga.

Chloroplasts are plant organelles that carry out oxygenic photosynthesis. Chloroplast biogenesis depends upon chloroplast ribosomes and their translational activity. However, regulation of chloroplast ribosome biogenesis remains an important unanswered question.