Spatiotemporal Relationships Between the Abundance, Distribution, and Potential Activities of Ammonia-Oxidizing and Denitrifying Microorganisms in Intertidal Sediments

Microbacterium mangrovi strain MUSC 115T was isolated from intertidal sediments of Kuantan, Malaysia. Here we describe the draft genome of amylolytic strain MUSC 115T with total size of 4.4 Mbp from 55 contigs and G + C content of 70.0%. Total of 4,096 coding genes were observed, with 2 putative amylases genes in the draft genome of MUSC 115T. These genome features of MUSC 115T can improve our understanding of its starch-degrading mechanism and general physiology of the species, which provide opportunities for biotechnological and industrial exploitation.

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Automatic monitoring of denitrification rates and capacities in activated sludge processes using fluorescence or redox potential

Water Science & Technology ◽

10.2166/wst.1998.0519 ◽

1998 ◽

Vol 37 (12) ◽

pp. 121-129 ◽

Cited By ~ 3

Author(s):

S. Isaacs ◽

Terry Mah ◽

S. K. Maneshin

Keyword(s):

Biological Activity ◽

Activated Sludge ◽

Redox Potential ◽

Treatment Plant ◽

Automatic Monitoring ◽

Organic Substrate ◽

Anoxic Zone ◽

Optimal Dosing ◽

Denitrifying Microorganisms ◽

Activated Sludge Processes

A novel method is described to automatically estimate several key parameters affecting denitrification in activated sludge processes: the nitrate concentration, the denitrification capacity, and the maximum (substrate unlimited) and actual denitrification rates. From these, the concentration of active denitrifying microorganisms and the quality of available organic substrate pool can be estimated. Additionally, a modification of the method allows the determination of the efficacy of various carbon substrates to enhance denitrification, and this can be used to determine optimal dosing rates of an external carbon source. The method is based on measurements of either fluorescence or redox potential (ORP) in an isolated mini-reactor, the Biological Activity Meter (BAM), situated in the anoxic zone of the wastewater treatment plant. Advantages of the method are that it is in situ, operating at the same temperature as in the measured anoxic zone, requires no pumps or pipes for mixed liquor sampling, consumes little or no reagents, and uses measurement signals which are instantaneous and low maintenance, one of which provides a direct measure of biological activity.

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Planetary Nebulae in M31: Abundances, and comparison with bright Planetary Nebulae in the LMC

Symposium - International Astronomical Union ◽

10.1017/s007418090013178x ◽

1997 ◽

Vol 180 ◽

pp. 475-476

Author(s):

M. G. Richer ◽

G. Stasińska ◽

M. L. McCall

Keyword(s):

Planetary Nebula ◽

Luminosity Function ◽

Large Population ◽

Wavelength Region ◽

Planetary Nebulae ◽

Surprising Result ◽

Population Synthesis ◽

Abundance Distribution ◽

Wide Range ◽

The Mean

We have obtained spectra of 28 planetary nebulae in the bulge of M31 using the MOS spectrograph at the Canada-France-Hawaii Telescope. Typically, we observed the [O II] λ3727 to He I λ5876 wavelength region at a resolution of approximately 1.6 å/pixel. For 19 of the 21 planetary nebulae whose [OIII]λ5007 luminosities are within 1 mag of the peak of the planetary nebula luminosity function, our oxygen abundances are based upon a measured [OIII]λ4363 intensity, so they are based upon a measured electron temperature. The oxygen abundances cover a wide range, 7.85 dex < 12 + log(O/H) < 9.09 dex, but the mean abundance is surprisingly low, 12 + log(O/H)–8.64 ± 0.32 dex, i.e., roughly half the solar value (Anders & Grevesse 1989). The distribution of oxygen abundances is shown in Figure 1, where the ordinate indicates the number of planetary nebulae with abundances within ±0.1 dex of any point on the x-axis. The dashed line indicates the mean abundance, and the dotted lines indicate the ±1 σ points. The shape of this abundance distribution seems to indicate that the bulge of M31 does not contain a large population of bright, oxygen-rich planetary nebulae. This is a surprising result, for various population synthesis studies (e.g., Bica et al. 1990) have found a mean stellar metallicity approximately 0.2 dex above solar. This 0.5 dex discrepancy leads one to question whether the mean stellar metallicity is as high as the population synthesis results indicate or if such metal-rich stars produce bright planetary nebulae at all. This could be a clue concerning the mechanism responsible for the variation in the number of bright planetary nebulae observed per unit luminosity in different galaxies (e.g., Hui et al. 1993).

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Effects of Organic Fertilizers on the Soil Microorganisms Responsible for N2O Emissions: A Review

Microorganisms ◽

10.3390/microorganisms9050983 ◽

2021 ◽

Vol 9 (5) ◽

pp. 983

Author(s):

Cristina Lazcano ◽

Xia Zhu-Barker ◽

Charlotte Decock

Keyword(s):

Community Structure ◽

Microbial Community ◽

Best Management Practices ◽

Management Practices ◽

Organic Fertilizers ◽

N2o Emissions ◽

Soil C ◽

Best Management ◽

C Stocks ◽

Denitrifying Microorganisms

The use of organic fertilizers constitutes a sustainable strategy to recycle nutrients, increase soil carbon (C) stocks and mitigate climate change. Yet, this depends largely on balance between soil C sequestration and the emissions of the potent greenhouse gas nitrous oxide (N2O). Organic fertilizers strongly influence the microbial processes leading to the release of N2O. The magnitude and pattern of N2O emissions are different from the emissions observed from inorganic fertilizers and difficult to predict, which hinders developing best management practices specific to organic fertilizers. Currently, we lack a comprehensive evaluation of the effects of OFs on the function and structure of the N cycling microbial communities. Focusing on animal manures, here we provide an overview of the effects of these organic fertilizers on the community structure and function of nitrifying and denitrifying microorganisms in upland soils. Unprocessed manure with high moisture, high available nitrogen (N) and C content can shift the structure of the microbial community, increasing the abundance and activity of nitrifying and denitrifying microorganisms. Processed manure, such as digestate, compost, vermicompost and biochar, can also stimulate nitrifying and denitrifying microorganisms, although the effects on the soil microbial community structure are different, and N2O emissions are comparatively lower than raw manure. We propose a framework of best management practices to minimize the negative environmental impacts of organic fertilizers and maximize their benefits in improving soil health and sustaining food production systems. Long-term application of composted manure and the buildup of soil C stocks may contribute to N retention as microbial or stabilized organic N in the soil while increasing the abundance of denitrifying microorganisms and thus reduce the emissions of N2O by favoring the completion of denitrification to produce dinitrogen gas. Future research using multi-omics approaches can be used to establish key biochemical pathways and microbial taxa responsible for N2O production under organic fertilization.

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Microplastics abundance, distribution, and composition in freshwater and sediments from the largest Xijin Wetland Park, Nanning, South China

Gondwana Research ◽

10.1016/j.gr.2021.07.009 ◽

2021 ◽

Author(s):

Qiuping Wang ◽

Kai Huang ◽

Yizheng Li ◽

Yanling Zhang ◽

Lei Yan ◽

...

Keyword(s):

South China ◽

Abundance Distribution

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The Variation on Sediment Reworking with Influencing Factors by a Sand Bubbler Crab, Scopimera globosa, in Intertidal Sediments of the Anmyeon Island, Korea

Sustainability ◽

10.3390/su13105703 ◽

2021 ◽

Vol 13 (10) ◽

pp. 5703

Author(s):

Jaehwan Seo ◽

Bon Joo Koo

Keyword(s):

Chlorophyll A ◽

Influencing Factors ◽

Surface Sediment ◽

Intertidal Sediments ◽

Daily Production ◽

Chlorophyll A Concentration ◽

Sediment Reworking ◽

Pellet Production ◽

Crab Density ◽

Annual Sediment

Though biological and ecological characteristics of Scopimera globosa have been intensively investigated, little has been understood on bioturbation, especially sediment reworking. This study was designed to evaluate variation on sediment reworking of S. globosa based on feeding pellet production (FP) and burrowing pellet production (BP) with influencing factors and estimating the chlorophyll content reduction within the surface sediment by its feeding. The FP and BP largely fluctuated according to chlorophyll a concentration and crab density, but both were not influenced by temperature. The FP was enhanced by chlorophyll a concentration, whereas both FP and BP were restricted by crab density. The daily individual production was highest in spring, followed by fall and summer, with values of 25.61, 20.70 and 3.90 g ind.−1 d−1, respectively, while the total daily production was highest in fall, followed by summer and spring 2150, 1660 and 660 g m−2 d−1, respectively. The daily sediment reworking based on the FP and BP of Scopimera was highest in fall, followed by summer and spring, with values of 1.91, 1.70 and 0.77 mm d-1 and the annual sediment reworking rate of this species was calculated 40 cm year−1 based on its density in this study area. The chlorophyll a reduction ratio was estimated from 11 to 24% in one day by its feeding. These results imply that the sediment reworking of S. globosa is regulated by food abundance and its density, and Scopimera is an important bioturbator, greatly influencing biogeochemical changes in the intertidal sediments.

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Complexes with Atomic Gold Ions: Efficient Bis-Ligand Formation

Molecules ◽

10.3390/molecules26123484 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3484

Author(s):

Felix Duensing ◽

Elisabeth Gruber ◽

Paul Martini ◽

Marcelo Goulart ◽

Michael Gatchell ◽

...

Keyword(s):

Polyatomic Molecules ◽

Rare Gas ◽

Abundance Distribution ◽

Degree Of Ionization ◽

Covalent Bonds ◽

Helium Nanodroplets ◽

Order Of Magnitude ◽

High Resolution Mass Spectrometer ◽

Dumbbell Structure ◽

Resolution Mass

Complexes of atomic gold with a variety of ligands have been formed by passing helium nanodroplets (HNDs) through two pickup cells containing gold vapor and the vapor of another dopant, namely a rare gas, a diatomic molecule (H2, N2, O2, I2, P2), or various polyatomic molecules (H2O, CO2, SF6, C6H6, adamantane, imidazole, dicyclopentadiene, and fullerene). The doped HNDs were irradiated by electrons; ensuing cations were identified in a high-resolution mass spectrometer. Anions were detected for benzene, dicyclopentadiene, and fullerene. For most ligands L, the abundance distribution of AuLn+ versus size n displays a remarkable enhancement at n = 2. The propensity towards bis-ligand formation is attributed to the formation of covalent bonds in Au+L2 which adopt a dumbbell structure, L-Au+-L, as previously found for L = Xe and C60. Another interesting observation is the effect of gold on the degree of ionization-induced intramolecular fragmentation. For most systems gold enhances the fragmentation, i.e., intramolecular fragmentation in AuLn+ is larger than in pure Ln+. Hydrogen, on the other hand, behaves differently, as intramolecular fragmentation in Au(H2)n+ is weaker than in pure (H2)n+ by an order of magnitude.

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