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Zhuo Chen, Guiying Zhang, Mingkun Yang, Tao Li, Feng Ge, Jindong Zhao
Nϵ-Acetylation of lysine residues represents a frequently occurring post-translational modification widespread in bacteria that plays vital roles in regulating bacterial physiology and metabolism. However, the role of lysine acetylation in cyanobacteria remains unclear, presenting a hurdle to in-depth functional study of this post-translational modification. Here, we report the lysine acetylome of Synechococcus sp. PCC 7002 (hereafter Synechococcus) using peptide prefractionation, immunoaffinity enrichment, and coupling with high-precision liquid chromatography-tandem mass spectrometry analysis...
May 26, 2017: Molecular & Cellular Proteomics: MCP
Jessica Hartwig Duarte, Jorge Alberto Vieira Costa
This study evaluated the intermittent addition of coal flue gas wastes (CO2, SO2, NO and ash) into a Synechococcus nidulans LEB 115 cultivation in terms of growth parameters, CO2 biofixation and biomass characterization. The microalga from a coal thermoelectric plant showed tolerance up to 200ppm SO2 and NO, with a maximum specific growth rate of 0.18±0.03d(-)(1). The addition of thermal coal ash to the cultivation increased the Synechococcus nidulans LEB 115 maximum cell growth by approximately 1.3 times...
May 13, 2017: Bioresource Technology
Róbson Ricardo Teixeira, Marcus Vinícius de Andrade Barros, Gustavo Costa Bressan, Raoni Pais Siqueira, Fabíola Suelen Dos Santos, Michele Bertazzini, Rudolf Kiralj, Márcia Miguel Castro Ferreira, Giuseppe Forlani
BACKGROUND: The photosynthetic apparatus is targeted by various herbicides, including several amides such as diuron and linuron. Considering the need for the discovery of new active ingredients to cope with weed resistance, the synthesis of a series of trifluoromethyl aryl amides is herein described whose inhibitory properties were assessed in vitro on the photosynthetic electron transport chain, and in vivo on the growth of a model cyanobacterial strain. Theoretical studies were also carried out...
May 25, 2017: Pest Management Science
Shaun Nielsen, Jackson Wilkes Walburn, Adriana Vergés, Torsten Thomas, Suhelen Egan
Most of our knowledge regarding the biodiversity of gut microbes comes from terrestrial organisms or marine species of economic value, with less emphasis on ecologically important species. Here we investigate the bacterial composition associated with the gut of Siganus fuscescens, a rabbitfish that plays an important ecological role in coastal ecosystems by consuming seaweeds. Members of Firmicutes, Bacteroidetes and delta-Proteobacteria were among the dominant taxa across samples taken from the contents and the walls (sites) of the midgut and hindgut (location)...
2017: PeerJ
Anurag P Srivastava, Emily P Hardy, James P Allen, Brian J Vaccaro, Michael K Johnson, David B Knaff
An in silico model for the 1:1 ferredoxin (Fd)/nitrate reductase (NR) complex, using the known structure of Synechocystis sp. PCC 6803 Fd and the in silico model of Synechococcus sp. PCC 7942 NR, is used to map the interaction sites that define the interface between Fd and NR. To test the electrostatic interactions predicted by the model complex, five positively charged NR amino acids Arg43, Arg46, Arg197, Lys201 and Lys614; and a negatively charged amino acid, Glu219, were altered using site-directed mutagenesis and characterized by activity measurements, metal analysis and EPR studies...
May 18, 2017: Biochemistry
Zhao Zhao, Michael Gonsior, Jenna Luek, Stephen Timko, Hope Ianiri, Norbert Hertkorn, Philippe Schmitt-Kopplin, Xiaoting Fang, Qinglu Zeng, Nianzhi Jiao, Feng Chen
Marine chromophoric dissolved organic matter (CDOM) and its related fluorescent components (FDOM), which are widely distributed but highly photobleached in the surface ocean, are critical in regulating light attenuation in the ocean. However, the origins of marine FDOM are still under investigation. Here we show that cultured picocyanobacteria, Synechococcus and Prochlorococcus, release FDOM that closely match the typical fluorescent signals found in oceanic environments. Picocyanobacterial FDOM also shows comparable apparent fluorescent quantum yields and undergoes similar photo-degradation behaviour when compared with deep-ocean FDOM, further strengthening the similarity between them...
May 17, 2017: Nature Communications
Lu Lu, Bao-Qing Zhao, Dan Miao, Wen-Long Ding, Ming Zhou, Hugo Scheer, Kai-Hong Zhao
Phytochromobilin (PΦB), the chromophore of plant phytochromes, is difficult to isolate because phytochromes occur at very low concentrations in plants. It is, therefore, frequently replaced in plant phytochrome studies by phycocyanobilin, which is abundant in cyanobacteria. PΦB is also an attractive chromophore for far-red emitting chromoproteins. In this work, we design and optimize a simple method to efficiently isolate useful quantities of PΦB: The chromophore is generated in Escherichia coli and transiently bound to a tailored chromophore-binding domain of ApcE2, the apo-protein of a core-membrane linker, from which it can subsequently be released...
May 2017: Photochemistry and Photobiology
Michael A Stravs, Francesco Pomati, Juliane Hollender
Phytoplankton constitute an important component of surface water ecosystems; however little is known about their contribution to biotransformation of organic micropollutants. To elucidate biotransformation processes, batch experiments with two cyanobacterial species (Microcystis aeruginosa and Synechococcus sp.) and one green algal species (Chlamydomonas reinhardtii) were conducted. Twenty-four micropollutants were studied, including 15 fungicides and 9 pharmaceuticals. Online solid phase extraction (SPE) coupled with liquid chromatography (LC)-high resolution tandem mass spectrometry (HRMS/MS) was used together with suspect and nontarget screening to identify transformation products (TPs)...
May 9, 2017: Environmental Science. Processes & Impacts
Oscar I Bernal, Bhuvnesh Bharti, Michael C Flickinger, Orlin D Velev
We report how dielectrophoresis (DEP) can be used as a tool for the fabrication of biocomposite coatings of photoreactive cyanobacteria (Synechococcus PCC7002) on flexible polyester sheets (PEs). The PE substrates were precoated by a layer-by-layer assembled film of charged polyelectrolytes. In excellent agreement between experimental data and numerical simulations, the directed assembly process driven by external electric field results in the formation of 1D chains and 2D sheets by the cells. The preassembled cyanobacteria chains and arrays became deposited on the substrate and remained in place after the electric field was turned off due to the electrostatic attraction between the negatively charged cell surfaces and the positively charged polyelectrolyte-coated PE...
May 18, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Lara J Jazmin, Yao Xu, Yi Ern Cheah, Adeola O Adebiyi, Carl Hirschie Johnson, Jamey D Young
We applied isotopically nonstationary (13)C metabolic flux analysis (INST-MFA) to compare the pathway fluxes of wild-type (WT) Synechococcus elongatus PCC 7942 to an engineered strain (SA590) that produces isobutyraldehyde (IBA). The flux maps revealed a potential bottleneck at the pyruvate kinase (PK) reaction step that was associated with diversion of flux into a three-step PK bypass pathway involving the enzymes PEP carboxylase (PEPC), malate dehydrogenase (MDH), and malic enzyme (ME). Overexpression of pk in SA590 led to a significant improvement in IBA specific productivity...
May 4, 2017: Metabolic Engineering
Jan Lüddecke, Liliana Francois, Philipp Spät, Björn Watzer, Tomasz Chilczuk, Gernot Poschet, Rüdiger Hell, Bernhard Radlwimmer, Karl Forchhammer
The citric acid cycle intermediate 2-oxoglutarate (2-OG, a.k.a. alpha-ketoglutarate) links the carbon and nitrogen metabolic pathways and can provide information on the metabolic status of cells. In recent years, it has become exceedingly clear that 2-OG also acts as a master regulator of diverse biologic processes in all domains of life. Consequently, there is a great demand for time-resolved data on 2-OG fluctuations that can't be adequately addressed using established methods like mass spectrometry-based metabolomics analysis...
May 3, 2017: Scientific Reports
Min-Kyoung Kang, Yongjin J Zhou, Nicolaas A Buijs, Jens Nielsen
BACKGROUND: Low catalytic activities of pathway enzymes are often a limitation when using microbial based chemical production. Recent studies indicated that the enzyme activity of aldehyde decarbonylase (AD) is a critical bottleneck for alkane biosynthesis in Saccharomyces cerevisiae. We therefore performed functional screening to identify efficient ADs that can improve alkane production by S. cerevisiae. RESULTS: A comparative study of ADs originated from a plant, insects, and cyanobacteria were conducted in S...
May 2, 2017: Microbial Cell Factories
Katyanne M Shoemaker, Pia H Moisander
Characterization of marine copepod gut microbiome composition and its variability provides information on function of marine food webs, biogeochemical cycles, and copepod health. Copepod gut microbiomes were investigated quarterly over two years at the Bermuda Atlantic Time-series Station in the North Atlantic Subtropical Gyre, while assessing seasonal shifts in stable and transient communities. Microbial communities were analyzed using amplicon sequencing targeting the bacterial 16S rRNA V3-V4 region and the cyanobacterial ntcA gene...
May 2, 2017: Environmental Microbiology
Scott C Pierobon, Jason Riordon, Brian Nguyen, Matthew D Ooms, David Sinton
High-density biomass production is currently only realized in biofilm-based photobioreactors. Harvest yields of whole biofilms are self-limited by daughter-upon-parent cell growth that hinders light and leads to respiratory biomass losses. In this work, we demonstrate a sustainable multi-harvest approach for prolonged generation of high-density biomass. Calcium-alginate hydrogel cultures loaded with Synechococcus elongatus PCC 7942 achieved production densities comparable to that of biofilms (10(9)  cells/mL) and optimal total productivity in harvest periods of 2 or 3 days that allowed high-density surface growth without self-limiting cell buildup or surface death...
May 2, 2017: Biotechnology and Bioengineering
Hsiang-Yen Su, Hsiang-Hui Chou, Te-Jin Chow, Tse-Min Lee, Jo-Shu Chang, Wen-Lii Huang, Hsien-Jung Chen
This study was undertaken to increase the biomass and carbohydrate productivities of a freshwater cyanobacterium Synechococcus elongatus under hot outdoor conditions through genetic manipulation to facilitate the application of using the cyanobacterial biomass as bio-refinery feedstocks. The stress tolerance genes (hspA, osmotin) were expressed in S. elongatus to improve their growth under various environment stresses of outdoor cultivation. The results revealed that over-expression of hspA and osmotin significantly improved temperature (45°C), high light intensity, and salt tolerances of S...
April 21, 2017: Bioresource Technology
Mark A Brzezinski, Jeffrey W Krause, Stephen B Baines, Jackie L Collier, Daniel C Ohnemus, Benjamin S Twining
Six clones of the marine cyanobacterium Synechococcus, representing four major clades, were all found to contain significant amounts of silicon in culture. Growth rate was unaffected by silicic acid, Si(OH)4 , concentration between 1 and 120 μM suggesting that Synechococcus lacks an obligate need for silicon (Si). Strains contained two major pools of Si: an aqueous soluble and an aqueous insoluble pool. Soluble pool sizes correspond to estimated intracellular dissolved Si concentrations of 2-24 mM, which would be thermodynamically unstable implying the binding of intracellular soluble Si to organic ligands...
April 29, 2017: Journal of Phycology
Beate M Slaby, Ute Hentschel
We report here four draft genome sequences belonging to clade F of the cyanobacterium "Candidatus Synechococcus spongiarum" of the marine sponge Aplysina aerophoba, which were collected from two nearby locations in the northern Adriatic Sea. The sequences provide the basis for within-clade comparisons between members of this widespread group of cyanobacterial sponge symbionts.
April 27, 2017: Genome Announcements
Norihiro Sato, Yuki Ebiya, Ryutaro Kobayashi, Yoshitaka Nishiyama, Mikio Tsuzuki
Sulfoquinovosyl diacylglycerol (SQDG) is present in the membranes of cyanobacteria or their descendants, plastids at species-dependent levels. We investigated the physiological significance of the intrinsic SQDG content in the cyanobacterium Synechococcus elongatus PCC 7942, with the use of its mutant, in which the genes for SQDG synthesis, sqdB and sqdX, were overexpressed. The mutant showed a 1.3-fold higher content of SQDG (23.6 mol% relative to total cellular lipids, cf., 17.1 mol% in the control strain) with much less remarkable effects on the other lipid classes...
April 24, 2017: Biochemical and Biophysical Research Communications
Aditya Sarnaik, Reena Pandit, Arvind Lali
Synechococcus elongatus PCC 7942 has been widely explored as cyanobacterial cell factory through genetic modifications for production of various value-added compounds. However, successful industrial scale-ups have not been reported for the system predominantly due to its obligate photoautotrophic metabolism and use of artificial light in photobioreactors. Hence, engineering the organism to perform mixotrophy under natural light could serve as an effective solution. Thus, we applied a genetically engineered strain of Synechococcus elongatus PCC 7942 expressing heterologous hexose transporter gene (galP) to perform mixotrophy under natural light in a temperature controlled environmental chamber (EC)...
April 26, 2017: Biotechnology Progress
Yongguang Jiang, Peng Xiao, Yang Liu, Jiangxin Wang, Renhui Li
Cyanobacterial blooms in eutrophic lakes are severe environmental problems worldwide. To characterize the spatiotemporal heterogeneity of cyanobacterial blooms, a high-throughput method is necessary for the specific detection of cyanobacteria. In this study, the cyanobacterial composition of three eutrophic waters in China (Taihu Lake, Dongqian Lake, and Dongzhen Reservoir) was determined by pyrosequencing the cpcBA intergenic spacer (cpcBA-IGS) of cyanobacteria. A total of 2585 OTUs were obtained from the normalized cpcBA-IGS sequence dataset at a distance of 0...
April 2017: Harmful Algae
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