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https://www.readbyqxmd.com/read/28429526/sll1783-a-monooxygenase-associated-with-polysaccharide-processing-in-the-unicellular-cyanobacterium-synechocystis-pcc-6803
#1
Hélder Miranda, Peter Immerzeel, Lorenz Gerber, Katarina Hörnaeus, Sara Bergström Lind, Bagmi Pattanaik, Pia Lindberg, Fikret Mamedov, Peter Lindblad
Cyanobacteria play a pivotal role as the primary producer in many aquatic ecosystems. The knowledge on the interacting processes of cyanobacteria with its environment - abiotic and biotic factors - is still very limited. Many potential exocytoplasmic proteins in the model unicellular cyanobacterium Synechocystis PCC 6803 have unknown functions and their study is essential to improve our understanding of this photosynthetic organism and its potential for biotechnology use. Here we characterize a deletion mutant of Synechocystis PCC 6803, ∆sll1783, a strain that showed a remarkably high light resistance which is related with its lower thylakoid membrane formation...
April 21, 2017: Physiologia Plantarum
https://www.readbyqxmd.com/read/28428249/crystal-structure-and-redox-properties-of-a-novel-cyanobacterial-heme-protein-with-a-his-cys-heme-axial-ligation-and-a-per-arnt-sim-pas-like-domain
#2
Taiki Motomura, Michihiro Suga, Rainer Hienerwadel, Akiko Nakagawa, Thanh-Lan Lai, Wolfgang Nitschke, Takahiro Kuma, Miwa Sugiura, Alain Boussac, Jain-Ren Shen
Photosystem II (PSII) catalyzes the light-induced water oxidation leading to the generation of dioxygen indispensable for sustaining aerobic life on Earth. The PSII reaction center is composed of D1 and D2 proteins encoded by the psbA and psbD genes, respectively. In cyanobacteria, different psbA genes are present in the genome. The thermophilic cyanobacterium Thermosynechococcus elongatus contains 3 psbA genes, psbA1, psbA2 and psbA3 and a new c-type heme protein, Tll0287, was found to be expressed in a strain expressing the psbA2 gene only, but the structure and function of Tll0287 are unknown...
April 20, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28423314/cyanobacteria-maintain-constant-protein-concentration-despite-genome-copy-number-variation
#3
Xiao-Yu Zheng, Erin K O'Shea
The cyanobacterium Synechococcus elongatus PCC 7942 has multiple copies of its single chromosome, and the copy number varies in individual cells, providing an ideal system to study the effect of genome copy-number variation on cell size and gene expression. Using single-cell fluorescence imaging, we found that protein concentration remained constant across individual cells regardless of genome copy number. Cell volume and the total protein amount from a single gene were both positively, linearly correlated with genome copy number, suggesting that changes in cell volume play an important role in buffering genome copy-number variance...
April 18, 2017: Cell Reports
https://www.readbyqxmd.com/read/28422340/leptolyngbyolides-cytotoxic-macrolides-from-the-marine-cyanobacterium-leptolyngbya-sp-isolation-biological-activity-and-catalytic-asymmetric-total-synthesis
#4
Jin Cui, Maho Morita, Osamu Ohno, Tomoyuki Kimura, Toshiaki Teruya, Takumi Watanabe, Kiyotake Suenaga, Masakatsu Shibasaki
Four new macrolactones, leptolyngbyolides A-D, were isolated from the cyanobacterium Leptolyngbya sp. collected in Okinawa, Japan. The planar structure of leptolyngbyolides were determined by extensive NMR studies, although complete assignment of the absolute configuration awaited the catalytic asymmetric total synthesis of leptolyngbyolide C. The synthesis took advantage of the catalytic asymmetric thioamide-aldol reaction using copper (I) complexed with a chiral bidentate phosphine ligand to regulate two key stereochemistries of the molecule at the outset...
April 19, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28420100/laucysteinamide-a-a-hybrid-pks-nrps-metabolite-from-a-saipan-cyanobacterium-cf-caldora-penicillata
#5
Chen Zhang, C Benjamin Naman, Niclas Engene, William H Gerwick
A bioactivity guided study of a cf. Caldora penicillata species, collected during a 2013 expedition to the Pacific island of Saipan, Northern Mariana Islands (a commonwealth of the USA), led to the isolation of a new thiazoline-containing alkaloid, laucysteinamide A (1). Laucysteinamide A is a new monomeric analogue of the marine cyanobacterial metabolite, somocystinamide A (2), a disulfide-bonded dimeric compound that was isolated previously from a Fijian marine cyanobacterium. The structure and absolute configuration of laucysteinamide A (1) was determined by a detailed analysis of its NMR, MS, and CD spectra...
April 14, 2017: Marine Drugs
https://www.readbyqxmd.com/read/28410570/natural-selection-drove-metabolic-specialization-of-the-chromatophore-in-paulinella-chromatophora
#6
Cecilio Valadez-Cano, Roberto Olivares-Hernández, Osbaldo Resendis-Antonio, Alexander DeLuna, Luis Delaye
BACKGROUND: Genome degradation of host-restricted mutualistic endosymbionts has been attributed to inactivating mutations and genetic drift while genes coding for host-relevant functions are conserved by purifying selection. Unlike their free-living relatives, the metabolism of mutualistic endosymbionts and endosymbiont-originated organelles is specialized in the production of metabolites which are released to the host. This specialization suggests that natural selection crafted these metabolic adaptations...
April 14, 2017: BMC Evolutionary Biology
https://www.readbyqxmd.com/read/28407086/toward-solar-biodiesel-production-from-co2-using-engineered-cyanobacteria
#7
Han Min Woo, Hyun Jeong Lee
Metabolic engineering of cyanobacteria has received attention as a sustainable strategy to convert carbon dioxide to various biochemicals including fatty acid-derived biodiesel. Recently, Synechococcus elongatus PCC 7942, a model cyanobacterium, has been engineered to convert CO2 to fatty acid ethyl esters (FAEEs) as biodiesel. Modular pathway has been constructed for FAEE production. Several metabolic engineering strategies were discussed to improve the production levels of FAEEs, including host engineering by improving CO2 fixation rate and photosynthetic efficiency...
April 12, 2017: FEMS Microbiology Letters
https://www.readbyqxmd.com/read/28406289/phylogenomic-analysis-of-the-microviridin-biosynthetic-pathway-coupled-with-targeted-chemoenzymatic-synthesis-yields-potent-protease-inhibitors
#8
Muhammad N Ahmed, Emmanuel Reyna González, Bianca Schmid, Vincent Wiebach, Roderich Suessmuth, Elke Dittmann, David P Fewer
Natural products and their semi-synthetic derivatives are an important source of drugs for the pharmaceutical industry. Bacteria are prolific producers of natural products and encode a vast diversity of natural product biosynthetic gene clusters. However, much of this diversity is inaccessible to natural product discovery. Here we use a combination of phylogenomic analysis of the microviridin biosynthetic pathway and chemo-enzymatic synthesis of bioinformatically predicted microviridins to yield new protease inhibitors...
April 13, 2017: ACS Chemical Biology
https://www.readbyqxmd.com/read/28402123/iron-isotope-fractionation-during-fe-ii-oxidation-mediated-by-the-oxygen-producing-marine-cyanobacterium-synechococcus-pcc-7002
#9
E D Swanner, T Bayer, W Wu, L Hao, M Obst, A Sundman, J M Byrne, F M Michel, I C Kleinhanns, A Kappler, R Schoenberg
In this study, we couple iron isotope analysis to microscopic and mineralogical investigation of iron speciation during circumneutral Fe(II) oxidation and Fe(III) precipitation with photosynthetically produced oxygen. In the presence of the cyanobacterium Synechococcus PCC 7002, aqueous Fe(II) (Fe(II)aq) is oxidized and precipitated as amorphous Fe(III) oxyhydroxide minerals (iron precipitates, Feppt), with distinct isotopic fractionation (ε(56)Fe) values determined from fitting the δ(56)Fe(II)aq (1.79‰ and 2...
April 21, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28401637/alcohol-tolerant-mutants-of-cyanobacterium-synechococcus-elongatus-pcc-7942-obtained-by-single-cell-mutant-screening-system
#10
Sayuri Arai, Kayoko Hayashihara, Yuki Kanamoto, Kazunori Shimizu, Yasutaka Hirokawa, Taizo Hanai, Akio Murakami, Hiroyuki Honda
Enhancement of alcohol tolerance in microorganisms is an important strategy for improving bioalcohol productivity. Although cyanobacteria can be used as a promising biocatalyst to produce various alcohols directly from CO2 , low productivity and low tolerance against alcohols are the main issues to be resolved. Nevertheless, to date, a mutant with increasing alcohol tolerance has rarely been reported.n this study, we attempted to select isopropanol (IPA)-tolerant mutants of Synechococcus elongatus PCC 7942 using UV-C-induced random mutagenesis, followed by enrichment of the tolerant candidates in medium containing 10 g/L IPA and screening of the cells with a high growth rate in the single cell culture system in liquid medium containing 10 g/L IPA...
April 12, 2017: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/28400530/phototaxis-of-cyanobacteria-under-complex-light-environments
#11
Minsu Kim
Photosynthetic bacteria are capable of producing their own food via photosynthesis. Unsurprisingly, they evolved the ability to move toward better light conditions (i.e., phototaxis). In a recent article in mBio, Chau et al. tuned the wavelength, flux, direction, and timing of light input and characterized the motility of the unicellular cyanobacterium Synechocystis sp. strain PCC6803 (R. M. W. Chau, D. Bhaya, and K. C. Huang, mBio 8:e02330-16, 2017, https://doi.org/10.1128/mBio.02330-16). The results revealed an intricate dependence of the motility on various light inputs, laying the fundamental groundwork toward understanding phototaxis under complex and dynamic light environments...
April 11, 2017: MBio
https://www.readbyqxmd.com/read/28398349/allelopathic-interactions-of-linoleic-acid-and-nitric-oxide-increase-the-competitive-ability-of-microcystis-aeruginosa
#12
Hao Song, Michel Lavoie, Xiaoji Fan, Hana Tan, Guangfu Liu, Pengfei Xu, Zhengwei Fu, Hans W Paerl, Haifeng Qian
The frequency and intensity of cyanobacterial blooms are increasing worldwide with major societal and economic costs. Interactions between toxic cyanobacteria and eukaryotic algal competitors can affect toxic bloom formation, but the exact mechanisms of interspecies interactions remain unknown. Using metabolomic and proteomic profiling of co-cultures of the toxic cyanobacterium Microcystis aeruginosa with a green alga as well as of microorganisms collected in a Microcystis spp. bloom in Lake Taihu (China), we disentangle novel interspecies allelopathic interactions...
April 11, 2017: ISME Journal
https://www.readbyqxmd.com/read/28398346/chemical-microenvironments-and-single-cell-carbon-and-nitrogen-uptake-in-field-collected-colonies-of-trichodesmium-under-different-pco2
#13
Meri J Eichner, Isabell Klawonn, Samuel T Wilson, Sten Littmann, Martin J Whitehouse, Matthew J Church, Marcel Mm Kuypers, David M Karl, Helle Ploug
Gradients of oxygen (O2) and pH, as well as small-scale fluxes of carbon (C), nitrogen (N) and O2 were investigated under different partial pressures of carbon dioxide (pCO2) in field-collected colonies of the marine dinitrogen (N2)-fixing cyanobacterium Trichodesmium. Microsensor measurements indicated that cells within colonies experienced large fluctuations in O2, pH and CO2 concentrations over a day-night cycle. O2 concentrations varied with light intensity and time of day, yet colonies exposed to light were supersaturated with O2 (up to ~200%) throughout the light period and anoxia was not detected...
April 11, 2017: ISME Journal
https://www.readbyqxmd.com/read/28394580/expanding-the-genetic-code-of-a-photoautotrophic-organism
#14
Yonatan Chemla, Mor Friedman, Mathias Heltberg, Anna Bakhrat, Elad Nagar, Rakefet Schwarz, Mogens Høgh Jensen, Lital Alfonta
The photoautotrophic freshwater cyanobacterium Synechococcus elongatus is widely used as a chassis for biotechnological applications as well as a photosynthetic bacterial model. In this study, a method for expanding the genetic code of this cyanobacterium has been established, thereby allowing the incorporation of unnatural amino acids into proteins. This was achieved through UAG stop codon suppression, using an archaeal pyrrolysyl orthogonal translation system. We demonstrate incorporation of unnatural amino acids into green fluorescent protein with 20 ± 3...
April 12, 2017: Biochemistry
https://www.readbyqxmd.com/read/28385852/complete-genome-sequence-of-a-coastal-cyanobacterium-synechococcus-sp-strain-nies-970
#15
Yohei Shimura, Yuu Hirose, Naomi Misawa, Sachiko Wakazuki, Takatomo Fujisawa, Yasukazu Nakamura, Yu Kanesaki, Haruyo Yamaguchi, Masanobu Kawachi
Members of the cyanobacterial genus Synechococcus are abundant in marine environments. To better understand the genomic diversity of marine Synechococcus spp., we determined the complete genome sequence of a coastal cyanobacterium, Synechococcus sp. NIES-970. The genome had a size of 3.1 Mb, consisting of one chromosome and four plasmids.
April 6, 2017: Genome Announcements
https://www.readbyqxmd.com/read/28378245/the-identification-of-isia-proteins-binding-chlorophyll-d-in-the-cyanobacterium-acaryochloris-marina
#16
Zheng-Ke Li, Yan-Chao Yin, Lu-Dan Zhang, Zhong-Chun Zhang, Guo-Zheng Dai, Min Chen, Bao-Sheng Qiu
The bioavailable iron in many aquatic ecosystems is extremely low, and limits the growth and photosynthetic activity of phytoplankton. In response to iron limitation, a group of chlorophyll-binding proteins known as iron stress-induced proteins are induced and serve as accessory light-harvesting components for photosystems under iron limitation. In the present study, we investigated physiological features of Acaryochloris marina in response to iron-deficient conditions. The growth doubling time under iron-deficient conditions was prolonged to ~3...
April 4, 2017: Photosynthesis Research
https://www.readbyqxmd.com/read/28377637/in-vitro-antibacterial-activity-of-mgdg-palmitoyl-from-oscillatoria-acuminata-ntapc05-against-extended-spectrum-%C3%AE-lactamase-producers
#17
Abdul Azees Parveez Ahamed, Mohammed Uddin Rasheed, Kalilurrahuman Peer Muhamed Noorani, Nazar Reehana, Subramanian Santhoshkumar, Yousuff Mohamed Mohamed Imran, Naiyf S Alharbi, Chinnathambi Arunachalam, Sulaiman Ali Alharbi, Mohammad Abdulkader Akbarsha, Nooruddin Thajuddin
Extended-spectrum β-lactamase (ESBL)-producing bacteria pose a big challenge in clinical practices, warranting a new therapeutic strategy. In this study, methanol extract of the marine cyanobacterium Oscillatoria acuminata NTAPC05 was fractionated under bioassay guidance and the fractions were tested against three well-characterized ESBL-producing bacteria Escherichia coli U655, Stenotrophomonas maltophilia B929 and Enterobacter asburiae B938. Out of the four HPLC fractions, fraction 2 showed bactericidal activity against all the three ESBL producers much more efficiently (MIC 100 μg ml(-1)) than the fourth-generation cephalosporin (MIC >125 μg ml(-1))...
April 5, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28371918/functional-lycopene-cyclase-crua-in-cyanobacterium-arthrospira-platensis-nies-39-and-its-role-in-carotenoid-synthesis
#18
Kenjiro Sugiyama, Masashi Ebisawa, Masaharu Yamada, Yoshiki Nagashima, Hideyuki Suzuki, Takashi Maoka, Shinichi Takaichi
The genus Arthrospira is filamentous, non-nitrogen-fixing cyanobacteria that is commercially important. We identified the molecular structures of carotenoids in Arthrospira platensis NIES-39. The major carotenoid identified was β-carotene. In addition, the hydroxyl derivatives of β-cryptoxanthin and (3R,3'R)-zeaxanthin were also found to be present. The carotenoid glycosides were identified as (3R,2'S)-myxol 2'-methylpentoside and oscillol 2,2'-dimethylpentoside. The methylpentoside moiety was a mixture of fucoside and chinovoside in an approximate ratio of 1 : 4...
April 1, 2017: Plant & Cell Physiology
https://www.readbyqxmd.com/read/28370986/gregarious-cyanobacteria
#19
Lucas J Stal
Huber and collaborators reported in this issue of Environmental Microbiology about freshwater picocyanobacteria that showed phenotypic plasticity in the sense that they appeared as single cells as well as in aggregates. The authors suggested that aggregation might be an inducible defense as a response to the presence of grazers. This has been described for eukaryotic phytoplankton and for the cyanobacterium Microcystis but thus far not for picocyanobacteria. Although inducible defense as an explanation is an attractive possibility, it is also problematic...
March 29, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28367229/robust-high-productivity-phototrophic-carbon-capture-at-high-ph-and-alkalinity-using-natural-microbial-communities
#20
Christine E Sharp, Sydney Urschel, Xiaoli Dong, Allyson L Brady, Greg F Slater, Marc Strous
BACKGROUND: Bioenergy with carbon capture and storage (BECCS) has come to be seen as one of the most viable technologies to provide the negative carbon dioxide emissions needed to constrain global temperatures. In practice, algal biotechnology is the only form of BECCS that could be realized at scale without compromising food production. Current axenic algae cultivation systems lack robustness, are expensive and generally have marginal energy returns. RESULTS: Here it is shown that microbial communities sampled from alkaline soda lakes, grown as biofilms at high pH (up to 10) and high alkalinity (up to 0...
2017: Biotechnology for Biofuels
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