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Katherine Graham, Linsey C Marr, Lauren M Sassoubre, Alexandria B Boehm
We characterized the microbial communities in SSA, water, and sand of three beaches in central California (Cowell Beach, Baker Beach, and Lovers Point) by sequencing the V4 region of the 16S rRNA gene. Average concentrations of 16S rRNA genes in SSA ranged from 2.4 × 104 to 1.4 × 105 gene copies per m3 of air. A total of 9,781 distinct OTUs were identified in SSA and of these, 1,042 OTUs were found in SSA of all beaches. SSA microbial communities included marine taxa, as well as some associated with the terrestrial environment...
January 15, 2018: FEMS Microbiology Ecology
Amr Badary, Shouhei Takamatsu, Mitsuharu Nakajima, Stefano Ferri, Peter Lindblad, Koji Sode
An important feature offered by marine cyanobacterial strains over freshwater strains is the capacity to grow in seawater, replacing the need for often-limited freshwater. However, there are only limited numbers of marine cyanobacteria that are available for genetic manipulation and bioprocess applications. The marine unicellular cyanobacteria Synechococcus sp. strain NKBG 15041c (NKBG15041c) has been extensively studied. Recombinant DNA technologies are available for this strain, and its genomic information has been elucidated...
January 12, 2018: Marine Biotechnology
Blanca Perez-Sepulveda, Frances Pitt, An Ngoc N'Guyen, Morgane Ratin, Laurence Garczarek, Andrew Millard, David J Scanlan
Marine picocyanobacteria of the genus Synechococcus are ubiquitous phototrophs in oceanic systems. Consistent with these organisms occupying vast tracts of the nutrient impoverished ocean, most marine Synechococcus so far studied are monoploid i.e. contain a single chromosome copy. The exception is the oligoploid strain Synechococcus sp. WH7803, which on average possesses around 4 chromosome copies. Here, we set out to understand the role of resource availability (through nutrient deplete growth) and physical stressors (UV, exposure to low and high temperature) in regulating ploidy level in this strain...
January 12, 2018: Environmental Microbiology Reports
Ryan L Clark, Gina C Gordon, Nathaniel R Bennett, Haoxiang Lyu, Thatcher W Root, Brian F Pfleger
As researchers engineer cyanobacteria for biotechnological applications, we must consider potential environmental release of these organisms. Previous theoretical work has considered cyanobacterial containment through elimination of the CO2-concentrating mechanism (CCM) to impose a high-CO2 requirement (HCR), which could be provided in the cultivation environment but not in the surroundings. In this work, we experimentally implemented an HCR containment mechanism in Synechococcus sp. PCC7002 (PCC7002) through deletion of carboxysome shell proteins and showed that this mechanism contained cyanobacteria in a 5% CO2 environment...
January 10, 2018: ACS Synthetic Biology
Narendran Sekar, Jian Wang, Yan Zhou, Yi Fang, Yajun Yan, Ramaraja P Ramasamy
Cyanobacteria are used as anode catalysts in photo-bioelectrochemical cells to generate electricity in a sustainable, economic and environmental friendly manner using only water and sunlight. Though cyanobacteria (CB) possess unique advantage for solar energy conversion by virtue of its robust photosynthesis, they cannot efficiently perform extracellular electron transfer (EET). The reasons being, unlike dissimilatory metal reducing bacteria (that are usually exploited in microbial fuel cells to generate electricity), (1) CB do not possess any special features on their outer membrane to carry out EET and (2) the electrons generated in photosynthetic electron transport chain are channeled into competing respiratory pathways rather than to the anode...
January 8, 2018: Biotechnology and Bioengineering
Satoru Watanabe, Hiroaki Ozawa, Hiroaki Kato, Kaori Nimura-Matsune, Toshifumi Hirayama, Fumitaka Kudo, Tadashi Eguchi, Katsumi Kakinuma, Hirofumi Yoshikawa
Owing to their photosynthetic capabilities, there is increasing interest in utilizing cyanobacteria to convert solar energy into biomass. 2-Deoxy-scyllo-inosose (DOI) is a valuable starting material for the benzene-free synthesis of catechol and other benzenoids. DOI synthase (DOIS) is responsible for the formation of DOI from d-glucose-6-phosphate (G6P) in the biosynthesis of 2-deoxystreptamine-containing aminoglycoside antibiotics such as neomycin and butirosin. DOI fermentation using a recombinant Escherichia coli strain has been reported, although a carbon source is necessary for high-yield DOI production...
January 3, 2018: Bioscience, Biotechnology, and Biochemistry
Marju Tamm, Peeter Laas, Rene Freiberg, Peeter Nõges, Tiina Nõges
Autotrophic picoplankton (0.2-2μm) can be a significant contributor to primary production and hence play an important role in carbon flow. The phytoplankton community structure in the Baltic Sea is very region specific and the understanding of the composition and dynamics of pico-size phytoplankton is generally poor. The main objective of this study was to determine the contribution of picoeukaryotic algae and their taxonomic composition in late summer phytoplankton community of the West-Estonian Archipelago Sea...
December 27, 2017: Science of the Total Environment
Yi-Qi Cao, Qian Li, Peng-Fei Xia, Liu-Jing Wei, Ning Guo, Jian-Wei Li, Shu-Guang Wang
As a novel chemical production platform, controllable and inducible modules in Synechococcus elongatus plus the ability of working in diurnal conditions are necessary. To the endeavors, inducible promoters, such as PTrc, have been refined from Escherichia coli, but the inducer isopropyl-β-D-thiogalactoside may cause several side-effects. Meanwhile, to promote the efficiency, photomixotrophic cultivation has been applied in S. elongatus with the additional organic carbon sources. In this study, we developed L-arabinose based modules consisted of both the PBAD inducible promoter and the metabolism of L-arabinose in S...
December 22, 2017: Scientific Reports
Xiaoyuan Chi, Zhimeng Zhang, Na Chen, Xiaowen Zhang, Mian Wang, Mingna Chen, Tong Wang, Lijuan Pan, Jing Chen, Zhen Yang, Xiangyu Guan, Shanlin Yu
BACKGROUND: Fatty acid desaturases are enzymes that introduce double bonds into fatty acyl chains. Extensive studies of fatty acid desaturases have been done in many plants. However, less is known about the diversity of this gene family in peanut (Arachis hypogaea L.), an important oilseed crop that is cultivated worldwide. RESULTS: In this study, twelve novel AhFADs genes were identified and isolated from peanut. Quantitative real-time PCR analysis indicated that the transcript abundances of AhFAB2-2 and AhFAD3-1 were higher in seeds than in other tissues examined, whereas the AhADS and AhFAD7-1 transcripts were more abundant in leaves...
2017: PloS One
Ginga Shimakawa, Satoru Watanabe, Chikahiro Miyake
A limitation in carbon dioxide (CO₂), which occurs as a result of natural environmental variation, suppresses photosynthesis and has the potential to cause photo-oxidative damage to photosynthetic cells. Oxygenic phototrophs have strategies to alleviate photo-oxidative damage to allow life in present atmospheric CO₂ conditions. However, the mechanisms for CO₂ limitation acclimation are diverse among the various oxygenic phototrophs, and many mechanisms remain to be discovered. In this study, we found that the gene encoding a CO₂ limitation-inducible protein, ColA, is required for the cyanobacterium Synechococcus sp...
December 15, 2017: Marine Drugs
Joseph Robert Piechura, Kapil Amarnath, Erin K O'Shea
The circadian clock interacts with other regulatory pathways to tune physiology to predictable daily changes and unexpected environmental fluctuations. However, the complexity of circadian clocks in higher organisms has prevented a clear understanding of how natural environmental conditions affect circadian clocks and their physiological outputs. Here, we dissect the interaction between circadian regulation and responses to fluctuating light in the cyanobacterium Synechococcus elongatus. We demonstrate that natural changes in light intensity substantially affect the expression of hundreds of circadian-clock-controlled genes, many of which are involved in key steps of metabolism...
December 14, 2017: ELife
Ekta Verma, Sindhunath Chakraborty, Balkrishna Tiwari, Arun K Mishra
PII protein family is widespread in prokaryotes and plants. In this study, impacts of PII deficiency on the synthesis of acetyl CoA and acetyl CoA carboxylase enzyme (ACCase) was analyzed in the Synechococcus sp. PCC 7942 by evaluating the mRNA levels of pyruvate kinase (PK), pyruvate dehydrogenase (PDH), citrate synthase (CS), biotin synthase (BS), biotin carboxylase (BC), biotin carboxyl carrier protein (BCCP), carboxyl transferase (CT) α and β subunits. The PII deficient Synechococcus sp. PCC 7942 showed upregulation of all the above-mentioned genes, except CS...
December 5, 2017: Journal of Basic Microbiology
Amandeep Kaur, Juan R Hernandez-Fernaud, Maria Del Mar Aguilo-Ferretjans, Elizabeth M Wellington, Joseph A Christie-Oleza
Marine phototroph and heterotroph interactions are vital in maintaining the nutrient balance in the oceans as essential nutrients need to be rapidly cycled before sinking to aphotic layers. The aim of this study was to highlight the molecular mechanisms that drive these interactions. For this we generated a detailed exoproteomic time-course analysis of a 100-day co-culture between the model marine picocyanobacterium Synechococcus sp. WH7803 and the Roseobacter strain Ruegeria pomeroyi DSS-3, both in nutrient-enriched and natural oligotrophic seawater...
December 1, 2017: Environmental Microbiology
Lennart T Bach, Santiago Alvarez-Fernandez, Thomas Hornick, Annegret Stuhr, Ulf Riebesell
The oceans absorb ~25% of the annual anthropogenic CO2 emissions. This causes a shift in the marine carbonate chemistry termed ocean acidification (OA). OA is expected to influence metabolic processes in phytoplankton species but it is unclear how the combination of individual physiological changes alters the structure of entire phytoplankton communities. To investigate this, we deployed ten pelagic mesocosms (volume ~50 m3) for 113 days at the west coast of Sweden and simulated OA (pCO2 = 760 μatm) in five of them while the other five served as controls (380 μatm)...
2017: PloS One
Pekka Patrikainen, Veronica Carbonell, Kati Thiel, Eva-Mari Aro, Pauli Kallio
Aldehyde deformylating oxygenase (ADO) is a unique enzyme found exclusively in photosynthetic cyanobacteria, which natively converts acyl aldehyde precursors into hydrocarbon products embedded in cellular lipid bilayers. This capacity has opened doors for potential biotechnological applications aiming at biological production of diesel-range alkanes and alkenes, which are compatible with the nonrenewable petroleum-derived end-products in current use. The development of production platforms, however, has been limited by the relative inefficiency of ADO enzyme, promoting research towards finding new strategies and information to be used for rational design of enhanced pathways for hydrocarbon over-expression...
December 2017: Metabolic Engineering Communications
Yasutaka Hirokawa, Shingo Matsuo, Hiroyuki Hamada, Fumio Matsuda, Taizo Hanai
BACKGROUND: Production directly from carbon dioxide by engineered cyanobacteria is one of the promising technologies for sustainable future. Previously, we have successfully achieved 1,3-propanediol (1,3-PDO) production using Synechococcus elongatus PCC 7942 with a synthetic metabolic pathway. The strain into which the synthetic metabolic pathway was introduced produced 3.48 mM (0.265 g/L) 1,3-PDO and 14.3 mM (1.32 g/L) glycerol during 20 days of incubation. In this study, the productivities of 1,3-PDO were improved by gene disruption selected by screening with in silico simulation...
November 25, 2017: Microbial Cell Factories
James A Bradley, Leslie K Daille, Christopher B Trivedi, Caitlin L Bojanowski, Blake W Stamps, Bradley S Stevenson, Heather S Nunn, Hope A Johnson, Sean J Loyd, William M Berelson, Frank A Corsetti, John R Spear
Ancient putative microbial structures that appear in the rock record commonly serve as evidence of early life on Earth, but the details of their formation remain unclear. The study of modern microbial mat structures can help inform the properties of their ancient counterparts, but modern mineralizing mat systems with morphological similarity to ancient structures are rare. Here, we characterize partially lithified microbial mats containing cm-scale dendrolitic coniform structures from a geothermal pool ("Cone Pool") at Little Hot Creek, California, that if fully lithified, would resemble ancient dendrolitic structures known from the rock record...
2017: NPJ Biofilms and Microbiomes
Mary H Abernathy, Jingjie Yu, Fangfang Ma, Michelle Liberton, Justin Ungerer, Whitney D Hollinshead, Saratram Gopalakrishnan, Lian He, Costas D Maranas, Himadri B Pakrasi, Doug K Allen, Yinjie J Tang
Background: Synechococcus elongatus UTEX 2973 is the fastest growing cyanobacterium characterized to date. Its genome was found to be 99.8% identical to S. elongatus 7942 yet it grows twice as fast. Current genome-to-phenome mapping is still poorly performed for non-model organisms. Even for species with identical genomes, cell phenotypes can be strikingly different. To understand Synechococcus 2973's fast-growth phenotype and its metabolic features advantageous to photo-biorefineries, 13C isotopically nonstationary metabolic flux analysis (INST-MFA), biomass compositional analysis, gene knockouts, and metabolite profiling were performed on both strains under various growth conditions...
2017: Biotechnology for Biofuels
Ya-Nan Jiao, Zhen-Chao Zhou, Tao Chen, Yuan-Yuan Wei, Ji Zheng, Rui-Xia Gao, Hong Chen
To evaluate the seasonal distribution of antibiotic resistance genes (ARGs) and explore the reason for their patterns in different seasons and different systems, two wastewater treatment systems were selected and analyzed using high-throughput qPCR. Linear discriminant analysis (LDA) effect size (LEfSe) was used to discover the differential ARGs (biomarkers) and estimate the biomarkers' effect size. We found that the total absolute abundances of ARGs in inflows and excess sludge samples had no obvious seasonal fluctuations, while those in winter outflow samples decreased in comparison with the inflow samples...
November 20, 2017: Environmental Pollution
Ruchi Pathania, Ahmad Ahmad, Shireesh Srivastava
Marine cyanobacteria play an important role in global carbon cycling and are a potential source of polyglucans for biotechnological purposes. This report provides the draft sequence of an Indian marine cyanobacterium, Synechococcus elongatus BDU 130192, which shows fast growth and high polyglucan content. The genome sequence will help in understanding the unique properties of this organism.
November 22, 2017: Genome Announcements
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