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Wen Wang, Yingbao Liu, Yongsheng Yang, Aizhen Wang, Kirill Sharshov, Yao Li, Mengyao Cao, Puzhen Mao, Laixing Li
In this study, we characterized for the first time the gut microbiota of Greylag geese (Anser anser) using high-throughput 16S rRNA gene sequencing technology. The results showed that the phyla Firmicutes (78.55%), Fusobacteria (9.38%), Proteobacteria (7.55%), Bacteroidetes (1.82%), Cyanobacteria (1.44%), and Actinobacteria (0.61%) dominated the gut microbial communities in the Greylag geese. Then, the variations of gut microbial community structures and functions among the three geese species, Greylag geese, Bar-headed geese (Anser indicus), and Swan geese (Anser cygnoides), were explored...
April 18, 2018: Journal of Basic Microbiology
Kirstin Gutekunst, Dörte Hoffmann, Ulrike Westernströer, Rüdiger Schulz, Dieter Garbe-Schönberg, Jens Appel
Cyanobacteria provide all components for sunlight driven biohydrogen production. Their bidirectional NiFe-hydrogenase is resistant against low levels of oxygen with a preference for hydrogen evolution. However, until now it was unclear if its catalytic efficiency can keep pace with the photosynthetic electron transfer rate. We identified NikKLMQO (sll0381-sll0385) as a nickel transporter, which is required for hydrogen production. ICP-MS measurements were used to quantify hydrogenase molecules per cell. We found 400 to 2000 hydrogenase molecules per cell depending on the conditions...
April 17, 2018: Scientific Reports
Zorigto Namsaraev, Olga Samylina, Marina Sukhacheva, Gennadii Borisenko, Dimitry Y Sorokin, Tatiana Tourova
Bitter-1 is a shallow hypersaline soda lake in Kulunda Steppe (Altai region, Russia). During a study period between 2005 and 2016, the salinity in the littoral area of the lake fluctuated within the range from 85 to 400 g/L (in July of each year). Light-dependent nitrogen fixation occurred in this lake up to the salt-saturating conditions. The rates increased with a decrease in salinity, both under environmental conditions and in laboratory simulations. The salinities below 100 g/L were favorable for light-dependent nitrogen fixation, while the process was dramatically inhibited above 200 g/L salts...
April 16, 2018: Extremophiles: Life Under Extreme Conditions
Andrea Di Cesare, Pedro J Cabello-Yeves, Nathan A M Chrismas, Patricia Sánchez-Baracaldo, Michaela M Salcher, Cristiana Callieri
BACKGROUND: Many cyanobacteria are capable of fixing atmospheric nitrogen, playing a crucial role in biogeochemical cycling. Little is known about freshwater unicellular cyanobacteria Synechococcus spp. at the genomic level, despite being recognised of considerable ecological importance in aquatic ecosystems. So far, it has not been shown whether these unicellular picocyanobacteria have the potential for nitrogen fixation. Here, we present the draft-genome of the new pink-pigmented Synechococcus-like strain Vulcanococcus limneticus...
April 16, 2018: BMC Genomics
D B Johnson, P A Beddows, T M Flynn, M R Osburn
Laguna Bacalar is a sulfate-rich freshwater lake on the Yucatan Peninsula that hosts large microbialites. High sulfate concentrations distinguish Laguna Bacalar from other freshwater microbialite sites such as Pavilion Lake and Alchichica, Mexico, as well as from other aqueous features on the Yucatan Peninsula. While cyanobacterial populations have been described here previously, this study offers a more complete characterization of the microbial populations and corresponding biogeochemical cycling using a three-pronged geobiological approach of microscopy, high-throughput DNA sequencing, and lipid biomarker analyses...
April 15, 2018: Geobiology
João M Medeiros, Désirée Böck, Gregor L Weiss, Romain Kooger, Roger A Wepf, Martin Pilhofer
Electron cryotomography is able to visualize macromolecular complexes in their cellular context, in a frozen-hydrated state, and in three dimensions. The method, however, is limited to relatively thin samples. Cryo-focused ion beam (FIB) milling is emerging as a powerful technique for sample thinning prior to cryotomography imaging. Previous cryo-FIB milling reports utilized custom-built non-standard equipment. Here we present a workflow and the required commercially available instrumentation to either implement the method de novo, or as an upgrade of pre-existing dual beam milling instruments...
April 6, 2018: Ultramicroscopy
Hangzhou Xu, Haiyan Pei, Yan Jin, Chunxia Ma, Yuting Wang, Jiongming Sun, Hongmin Li
The microbial community structures of drinking water treatment sludge (DWTS) generated for raw water (RW) from different locations and with different source types - including river water, lake water and reservoir water -were investigated using high-throughput sequencing. Because the unit operations in the six DWTPs were similar, community composition in fresh sludge may be determined by microbial community in the corresponding RW. Although Proteobacteria, Cyanobacteria, Bacteroidetes, Firmicutes, Verrucomicrobia, and Planctomycetes were the dominant phyla among the six DWTS samples, no single phylum exhibited similar abundance across all the samples, owing to differences in total phosphorus, chemical oxygen demand, Al, Fe, and chloride in RW...
April 10, 2018: Science of the Total Environment
Rabia Mazmouz, Insaf Essadik, Djemel Hamdane, Annick Méjean, Olivier Ploux
Cylindrospermopsin, a cytotoxin from cyanobacteria, is biosynthesized by a complex pathway, which involves CyrI, an iron and 2-oxoglutarate dependent hydroxylase that transforms 7-deoxy-cylindrospermopsin into cylindrospermopsin and its epimer, 7-epi-cylindrospermopsin, in the last step. The activity of CyrI from Oscillatoria sp. PCC 7926 depends on Fe(II) (Km  = 2.1 μM), and 2-oxoglutarate (Km  = 3.2 μM), and is strongly inhibited by 7-deoxy-cylindrospermopsin at concentration higher than 1 μM...
April 10, 2018: Archives of Biochemistry and Biophysics
Schalk J du Plooy, Akash Anandraj, Sarah White, Renzo Perissinotto, Derek R du Preez
Worldwide, cyanobacterial blooms are becoming more frequent, exacerbated by eutrophication, anthropogenic effects, and global climate change. Environmental factors play a direct role in photosynthesis of cyanobacteria and subsequent cellular changes, growth, and bloom dynamics. This study investigated the photosynthetic functioning of a persistent bloom-forming (18 months) cyanobacterium, Cyanothece sp., isolated from Lake St Lucia, South Africa. DUAL-PAM fluorometric methods were used to observe physiological responses in Cyanothece sp...
April 12, 2018: Extremophiles: Life Under Extreme Conditions
Chenyi Fei, Yuansheng Cao, Qi Ouyang, Yuhai Tu
Biological systems need to function accurately in the presence of strong noise and at the same time respond sensitively to subtle external cues. Here we study design principles in biochemical oscillatory circuits to achieve these two seemingly incompatible goals. We show that energy dissipation can enhance phase sensitivity linearly by driving the phase-amplitude coupling and increase timing accuracy by suppressing phase diffusion. Two general design principles in the key underlying reaction loop formed by two antiparallel pathways are found to optimize oscillation performance with a given energy budget: balancing the forward-to-backward flux ratio between the two pathways to reduce phase diffusion and maximizing the net flux of the phase-advancing pathway relative to that of the phase-retreating pathway to enhance phase sensitivity...
April 12, 2018: Nature Communications
Bin Ji, Hui Qin, Shaodong Guo, Wei Chen, Xuechun Zhang, Jiechao Liang
Knowing the microbial compositions in fresh lakes is significant to explore the mechanisms of eutrophication and algal blooms. This study reported on the bacterial communities of the four adjacent fresh lakes at different trophic status by Illumina MiSeq Platform, which were Tangxun Lake (J1), Qingling Lake (J2), Huangjia Lake (J3) and Niushan Lake (J4) in Wuhan, China. J1 had the highest salinity and phosphorus. J2 was abundant in TC (Total Carbon)/TOC (Total Organic Carbon.), calcium and magnesium. J3 had the highest content of nitrogen, iron and pollution of heavy metals...
April 9, 2018: Ecotoxicology and Environmental Safety
Lin-Rui Tan, Peng-Fei Xia, Raymond J Zeng, Qian Li, Xue-Fei Sun, Shu-Guang Wang
The interactions between antibiotics and microorganisms have attracted enormous research attentions. In this study, we investigated the effects of two typical aminoglycoside antibiotics on the aggregation of the model cyanobacterium, Synechococcus elongatus, and the dominating strain in algal blooms, Microcystis aeruginosa, via the analysis of zeta potentials, hydrophobicity, and extracellular polymeric substances (EPS) secretion. The results showed that low-level antibiotics promoted the aggregation of S. elongatus and M...
April 11, 2018: Environmental Science and Pollution Research International
Xiaojuan Wang, Jie Gu, Hua Gao, Xun Qian, Haichao Li
The spread of antibiotic resistance genes in river systems is an emerging environmental issue due to their potential threat to aquatic ecosystems and public health. In this study, we used droplet digital polymerase chain reaction (ddPCR) to evaluate pollution with clinically relevant antibiotic resistance genes (ARGs) at 13 monitoring sites along the main stream of the Weihe River in China. Six clinically relevant ARGs and a class I integron-integrase ( intI1 ) gene were analyzed using ddPCR, and the bacterial community was evaluated based on the bacterial 16S rRNA V3-V4 regions using MiSeq sequencing...
April 10, 2018: International Journal of Environmental Research and Public Health
Xiaolong Yao, Yunlin Zhang, Lu Zhang, Yongqiang Zhou
The global application of nitrogen is far greater than phosphorus, and it is widely involved in the eutrophication of lakes and reservoirs. We used a bibliometric method to quantitatively and qualitatively evaluate nitrogen research in eutrophic lakes and reservoirs to reveal research developments, current research hotspots, and emerging trends in this area. A total of 2695 articles in the past 25years from the online database of the Scientific Citation Index Expended (SCI-Expanded) were analyzed. Articles in this area increased exponentially from 1991 to 2015...
April 2018: Journal of Environmental Sciences (China)
Hamid Y Dar, Yaqoob Lone, Raj Kumar Koiri, Pradyumna K Mishra, Rupesh K Srivastava
Osteoporosis or enhanced bone loss is one of the most commonly occurring bone conditions in the world, responsible for higher incidence of fractures leading to increased morbidity and mortality in adults. Bone loss is affected by various environmental factors including diet, age, drugs, toxins etc. Microcystins are toxins produced by cyanobacteria with microcystin-LR being the most abundantly found around the world effecting both human and animal health. The present study demonstrates that MC-LR treatment induces bone loss and impairs both trabecular and cortical bone microarchitecture along with decreasing the mineral density and heterogeneity of bones in mice...
April 3, 2018: Environmental Pollution
Alexandra A Popova, Ulla Rasmussen, Tatiana A Semashko, Vadim M Govorun, Olga A Koksharova
Various species of cyanobacteria, diatoms and dinoflagellates are capable of synthesizing the non-proteinogenic neurotoxic amino acid β-N-methylamino-L-alanine (BMAA), which is known to be a causative agent of human neurodegeneration. Similar to most cyanotoxins, the biological and ecological functions of BMAA in cyanobacteria are unknown. In this study, we show for the first time that BMAA, in micromolar amounts, inhibits the formation of heterocysts (specialized nitrogen-fixing cells) in heterocystous, diazotrophic cyanobacteria (Anabaena sp...
April 6, 2018: Environmental Microbiology Reports
Esperança Gacia, Teresa Buchaca, Nayeli Bernal-Mendoza, Ibor Sabás, Enric Ballesteros, Marc Ventura
Submersed aquatic plants are a key component of shallow, clear water lakes contributing to primary production and water quality. High mountain lakes are naturally fishless although invasive trout and most recently minnows have been introduced causing a major impact on fauna richness. The Pyrenean high mountain range has preserved soft-water oligotrophic boreal isoetids in their southern limit of distribution but the recent fish introduction is a potential factor of stress that needs to be addressed. We here work under the hypothesis that due to contrasting ecological features, trout will not be heavily affecting quillwort populations while minnows will have a stronger effect on zooplankton and zoobenthos that will promote algal growth and reduce light availability for the underwater meadows...
2018: Frontiers in Plant Science
Yinhui Liu, Xiaobo Song, Huimin Zhou, Xue Zhou, Yunlong Xia, Xin Dong, Wei Zhong, Shaoying Tang, Lili Wang, Shu Wen, Jing Xiao, Li Tang
Background: Statin has been widely used to treat hyperlipidemia because of its high potency in decreasing cholesterol levels. The present study aimed to examine the lipid-lowering effect of rosuvastatin and the composition, diversity and species abundance of gut microbiome in association with rosuvastatin efficacy. TRIAL REGISTRATION: ChiCTR-ORC-17013212 at the First Affiliated Hospital of Dalian Medical University, November 2, 2017. Results: Totally 64 patients with hyperlipidemia were treated with 10 mg/day of rosuvastatin for 4-8 weeks...
2018: Frontiers in Microbiology
Anna Rymuszka, Anna Sieroslawska
Nodularin, one of the toxins produced by cyanobacteria commonly occurring in brackish waters, is a cyclic pentapeptide, that may exert adverse effects on animal and human health. The aim of the present study was to evaluate the cytotoxicity of nodularin on different fish cellular models. The leukocytes isolated from carp head kidney and common carp (Cyprinus carpio L.) leukocyte cell line (CLC) were incubated with the cyanotoxin at the concentrations of 0.001, 0.01, 0.05 or 0.1 μg/mL. Treatment of cells with the higher concentrations of the toxin resulted in a dramatic decrease in cell viability...
April 2, 2018: Toxicon: Official Journal of the International Society on Toxinology
Sosuke Ogawa, Yoshikazu Yazaki
The bark of Acacia mearnsii De Wild. (black wattle) contains significant amounts of water-soluble components acalled "wattle tannin". Following the discovery of its strong antioxidant activity, a wattle tannin dietary supplement has been developed and as part of developing new dietary supplements, a literature search was conducted using the SciFinder data base for " Acacia species and their biological activities". An analysis of the references found indicated that the name of Acacia nilotica had been changed to Vachellia nilotica , even though the name of the genus Acacia originated from its original name...
April 5, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
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