scholarly journals Impacts of biogenic polyunsaturated aldehydes on metabolism and community composition of particle-attached bacteria in coastal hypoxia

2020 ◽  
Author(s):  
Zhengchao Wu ◽  
Qian P. Li ◽  
Zaiming Ge ◽  
Bangqin Huang ◽  
Chunming Dong
Keyword(s):  
Community Structure ◽  
Bottom Layer ◽  
Bacterial Respiration ◽  
High Dose ◽  
Significant Shift ◽  
Low Oxygen ◽  
Oxygen Utilization ◽  
Salt Wedge ◽  
Attached Bacteria ◽  
Polyunsaturated Aldehydes

Abstract. Eutrophication-driven coastal hypoxia is of great interest recently, though its mechanisms are not fully understood. Here, we showed elevated concentrations of particulate and dissolved polyunsaturated aldehydes (PUAs) associated with the hypoxic waters meanly dominated by particle-attached bacteria (PAB) in the bottom water of a salt-wedge estuary. Particle-adsorbed PUAs of ~ 10 micromoles per liter particle in the hypoxic waters were directly quantified for the first time using large-volume-filtration followed with on-site derivation and extraction of the adsorbed PUAs. PUAs-amended incubation experiments for PAB retrieved from the low-oxygen waters were also performed to explore the impacts of PUAs on the growth and metabolism of PAB and associated oxygen utilization. We found an increase in cell growth of PAB in response to low-dose PUAs (1 μmol L−1) but an enhanced cell-specific metabolic activity in response to high-dose PUAs (100 μmol L−1) including bacterial respiration and production. Improved cell-specific metabolism of PAB in response to high-dose PUAs was also accompanied by a significant shift of PAB community structure with increased dominance of genus Alteromonas within the Gammaproteobacteria. We thus conclude that a high PUAs concentration within the bottom layer may be important for species such as Alteromonas to regulate PAB community structure and lead to the enhancement of oxygen utilization during the degradation of particulate organic matters and thus contribute to the formation of coastal hypoxia. These findings are potentially important for coastal systems with large river inputs, intense phytoplankton blooms driven by eutrophication, as well as strong hypoxia developed below the salt-wedge front.

scholarly journals Impacts of biogenic polyunsaturated aldehydes on metabolism and community composition of particle-attached bacteria in coastal hypoxia

2021 ◽  
Vol 18 (3) ◽  
pp. 1049-1065
Author(s):  
Zhengchao Wu ◽  
Qian P. Li ◽  
Zaiming Ge ◽  
Bangqin Huang ◽  
Chunming Dong
Keyword(s):  
Community Structure ◽  
Bottom Layer ◽  
Large River ◽  
Bacterial Respiration ◽  
High Dose ◽  
Low Oxygen ◽  
Oxygen Utilization ◽  
Salt Wedge ◽  
Attached Bacteria ◽  
Polyunsaturated Aldehydes

Abstract. Eutrophication-driven coastal hypoxia has been of great interest for decades, though its mechanisms remain not fully understood. Here, we showed elevated concentrations of particulate and dissolved polyunsaturated aldehydes (PUAs) associated with the hypoxic waters in the bottom layer of a salt-wedge estuary. Bacterial respiration within the hypoxic waters was mainly contributed by particle-attached bacteria (PAB) (> 0.8 µm), with free-living bacteria (0.2–0.8 µm) only accounting for 25 %–30 % of the total rate. The concentrations of particle-adsorbed PUAs (∼ 10 µmol L−1) in the hypoxic waters were directly quantified for the first time based on large-volume filtration and subsequent on-site PUA derivation and extraction. PUA-amended incubation experiments for PAB (> 25 µm) associated with sinking or suspended particles retrieved from the low-oxygen waters were also performed to explore the impacts of PUAs on the growth and metabolism of PAB and associated oxygen utilization. We found an increase in cell growth of PAB in response to low-dose PUAs (1 µmol L−1) but an enhanced cell-specific bacterial respiration and production in response to high-dose PUAs (100 µmol L−1). Improved cell-specific metabolism of PAB in response to high-dose PUAs was also accompanied by a shift of PAB community structure with increased dominance of the genus Alteromonas within the Gammaproteobacteria. We thus conclude that a high PUA concentration associated with aggregate particles within the bottom layer may be crucial for some species within Alteromonas to regulate PAB community structure. The change in bacteria community could lead to an enhancement of oxygen utilization during the degradation of particulate organic matter and thus likely contribute to the formation of coastal hypoxia. These findings are potentially important for coastal systems with large river inputs, intense phytoplankton blooms driven by eutrophication, and strong hypoxia developed below the salt-wedge front.

Dynamics of bacterial respiration and related growth efficiency, dissolved nutrients and dissolved oxygen concentration in a subarctic coastal embayment

2002 ◽  
Vol 53 (1) ◽  
pp. 1 ◽  
Author(s):  
Choon Weng Lee ◽  
I. Kudo ◽  
T. Yokokawa ◽  
M. Yanada ◽  
Y. Maita
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Bacterial Growth ◽  
Bottom Layer ◽  
Nutrient Concentrations ◽  
Bacterial Respiration ◽  
Dissolved Oxygen Concentration ◽  
Oxygen Utilization ◽  
Principal Mechanism ◽  
Funka Bay

Temporal variations in dissolved oxygen, nutrient concentrations and oxygen utilization rates (<0.7 m fraction) were recorded for almost two years in the subarctic Funka Bay, Japan. Dissolved inorganic nitrogen ranged from 0 to 26 M, phosphate from 0 to 2 M and silicate from 1 to 64 M. There was evidence of nitrogen limitation. Dissolved oxygen concentration ranged from 130 to 440 M, and decreased to <150 M in the bottom layer in summer. The rate of oxygen utilization, attributed to bacterial respiration, ranged from 0.6 to 9.3 M day–1 at 10 m depth, and from 0.8 to 5.0 M day–1 at 90 m depth, and was the principal mechanism causing the decrease in dissolved oxygen in the bottom layer in the summer. Bacterial growth efficiencies calculated for the 10 m and 90 m depths were similar: 1.6–17.2% and 1.4–23.6%, respectively. With the bacterial growth efficiencies <25%, the bacteria in Funka Bay acted as a net sink of carbon, where >75% of the organic matter flux through bacteria could be mineralized to CO2.

Linking Microbial Community Dynamics in BIOX® Leaching Tanks to Process Conditions: Integrating Lab and Commercial Experience

2017 ◽  
Vol 262 ◽  
pp. 38-42 ◽  
Author(s):  
Mariette Smart ◽  
Robert J. Huddy ◽  
Catherine J. Edward ◽  
Charl Fourie ◽  
Trust Shumba ◽  
...  
Keyword(s):  
South Africa ◽  
Community Structure ◽  
Microbial Community ◽  
Research University ◽  
Community Dynamics ◽  
Operating Conditions ◽  
Process Conditions ◽  
Significant Shift ◽  
Engineering Research ◽  
Microbial Community Dynamics

In the commercial BIOX® process, an acidophilic mixed bacterial and archaeal community dominated by iron and sulphur oxidising microorganisms is used to facilitate the recovery of precious metals from refractory gold-bearing sulphidic mineral concentrates. Characterisation of the microbial communities associated with commercial BIOX® reactors from four continents revealed a significant shift in the microbial community structure compared to that of the seed culture, maintained at SGS (South Africa). This has motivated more detailed study of the microbial community dynamics in the process. Microbial speciation of a subset of the BIOX® reactors at Fairview mines (Barberton, South Africa) and two laboratory maintained reactors housed at Centre for Bioprocess Engineering Research, University of Cape Town, has been performed tri-annually for three years by quantitative real-time polymerase chain reaction. The laboratory BIOX® culture maintained on Fairview concentrate was dominated by the desired iron oxidiser, Leptospirillum ferriphilum, and sulphur oxidiser, Acidithiobacillus caldus, when operated under standard BIOX® conditions. Shifts in the microbial community as a result of altered operating conditions were transient and did not result in a loss of the microbial diversity of the BIOX® culture. The community structure of the Fairview mines BIOX® reactor tanks showed archaeal dominance of these communities by organisms such as the iron oxidiser Ferroplasma acidiphilum and a Thermoplasma sp. for the period monitored. Shifts in the microbial community were observed across the monitoring period and mapped to changes in performance of the commercial process plant. Understanding the effect of changes in the plant operating conditions on the BIOX® community structure may assist in providing conditions that support the desired microbial consortium for optimal biooxidation to maximize gold recovery.

scholarly journals Zooplankton Community Response to Seasonal Hypoxia: A Test of Three Hypotheses

Diversity ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 21 ◽  
Author(s):  
Julie E. Keister ◽  
Amanda K. Winans ◽  
BethElLee Herrmann
Keyword(s):  
Community Structure ◽  
Puget Sound ◽  
Temporal Stability ◽  
Zooplankton Community ◽  
Community Response ◽  
Crustacean Zooplankton ◽  
Zooplankton Abundance ◽  
Calanoid Copepods ◽  
Low Oxygen ◽  
Seasonal Hypoxia

Several hypotheses of how zooplankton communities respond to coastal hypoxia have been put forward in the literature over the past few decades. We explored three of those that are focused on how zooplankton composition or biomass is affected by seasonal hypoxia using data collected over two summers in Hood Canal, a seasonally-hypoxic sub-basin of Puget Sound, Washington. We conducted hydrographic profiles and zooplankton net tows at four stations, from a region in the south that annually experiences moderate hypoxia to a region in the north where oxygen remains above hypoxic levels. The specific hypotheses tested were that low oxygen leads to: (1) increased dominance of gelatinous relative to crustacean zooplankton, (2) increased dominance of cyclopoid copepods relative to calanoid copepods, and (3) overall decreased zooplankton abundance and biomass at hypoxic sites compared to where oxygen levels are high. Additionally, we examined whether the temporal stability of community structure was decreased by hypoxia. We found evidence of a shift toward more gelatinous zooplankton and lower total zooplankton abundance and biomass at hypoxic sites, but no clear increase in the dominance of cyclopoid relative to calanoid copepods. We also found the lowest variance in community structure at the most hypoxic site, in contrast to our prediction. Hypoxia can fundamentally alter marine ecosystems, but the impacts differ among systems.

scholarly journals Antibiotic resistome and microbial community structure during anaerobic co-digestion of food waste, paper and cardboard

2020 ◽  
Vol 96 (2) ◽  
Author(s):  
Kärt Kanger ◽  
Nigel G H Guilford ◽  
HyunWoo Lee ◽  
Camilla L Nesbø ◽  
Jaak Truu ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Solid State ◽  
Food Waste ◽  
Microbial Community Structure ◽  
Microbial Community Composition ◽  
Microbial Community Analysis ◽  
Waste Paper ◽  
Rrna Gene ◽  
Significant Shift

ABSTRACT Solid organic waste is a significant source of antibiotic resistance genes (ARGs) and effective treatment strategies are urgently required to limit the spread of antimicrobial resistance. Here, we studied ARG diversity and abundance as well as the relationship between antibiotic resistome and microbial community structure within a lab-scale solid-state anaerobic digester treating a mixture of food waste, paper and cardboard. A total of 10 samples from digester feed and digestion products were collected for microbial community analysis including small subunit rRNA gene sequencing, total community metagenome sequencing and high-throughput quantitative PCR. We observed a significant shift in microbial community composition and a reduction in ARG diversity and abundance after 6 weeks of digestion. ARGs were identified in all samples with multidrug resistance being the most abundant ARG type. Thirty-two per cent of ARGs detected in digester feed were located on plasmids indicating potential for horizontal gene transfer. Using metagenomic assembly and binning, we detected potential bacterial hosts of ARGs in digester feed, which included Erwinia, Bifidobacteriaceae, Lactococcus lactis and Lactobacillus. Our results indicate that the process of sequential solid-state anaerobic digestion of food waste, paper and cardboard tested herein provides a significant reduction in the relative abundance of ARGs per 16S rRNA gene.

Biodegradation of Organic Substances by Biological Activated Carbon – Simulation of Bacterial Activity on Granular Activated Carbon

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2031-2034 ◽  
Author(s):  
W. Nishijima ◽  
M. Tojo ◽  
M. Okada ◽  
A. Murakami
Keyword(s):  
Activated Carbon ◽  
Community Structure ◽  
Granular Activated Carbon ◽  
Bacterial Activity ◽  
Organic Substances ◽  
Aminobenzoic Acid ◽  
Biological Activated Carbon ◽  
Support Medium ◽  
Attached Bacteria ◽  
The Difference

Biodegradation of organic substances by attached bacteria on biological activated carbon (BAC) was studied to clarify the advantages of granular activated carbon (GAC) as support media over conventional media without adsorption capacity with regard to biodegradation activity and community structure of attached bacteria. Anthracite (AN) was used as reference support medium without adsorbability. Low molecular organic substances with different biodegradability and adsorbability (phenol, glucose, benzoic acid and m-aminobenzoic acid) were fed into completely mixed BAC and AN reactors. The rate of biodegradation by BAC reactors fed with biodegradable organic substances was approximately 3 times as high as that by AN reactors. The difference in adsorbability of organic substances onto GAC had little effects on the rate of biodegradation. The structure of GAC with micro and macro pores did not provide better habitat for attached bacteria with regard to the size of population in comparison with anthracite without pores. The rates of biodegradation per attached bacteria for biodegradable organic substances in the BAC reactors were from 1.7 to 4.9 times higher than those in the AN reactors. GAC, as a bacterial support media, stimulated the biodegradation activity of each bacteria without increase in their population and probably with little change in their species composition. Although the number of attached bacteria on BAC was not different significantly from that on anthracite, m-aminobenzoic acid with low biodegradability was degraded only by the GAC reactor.

scholarly journals Oxygen Utilization and Downward Carbon Flux in an Oxygen-Depleted Eddy in the Eastern Tropical North Atlantic

2016 ◽  
Author(s):  
B. Fiedler ◽  
D. Grundle ◽  
F. Schütte ◽  
J. Karstensen ◽  
C. R. Löscher ◽  
...  
Keyword(s):  
Organic Matter ◽  
North Atlantic ◽  
Lower Boundary ◽  
Euphotic Zone ◽  
Shallow Depth ◽  
Surface Mixed Layer ◽  
Low Oxygen ◽  
Oxygen Utilization ◽  
Near Surface ◽  
Tropical North Atlantic

Abstract. The occurrence of mesoscale eddies that develop an extreme low oxygen environment at shallow depth (about 40 to 100 m) has recently been reported for the eastern tropical North Atlantic (ETNA). Their hydrographic structure suggests that the water mass inside the eddy is well isolated from ambient waters supporting the development of severe near-surface oxygen deficits. So far, hydrographic and biogeochemical characterization of these eddies was limited to a few autonomous surveys, using moorings, underwater gliders and profiling floats. In this study we present results from the first dedicated biogeochemical survey of one of these eddies conducted in March 2014 near the Cape Verde Ocean Observatory (CVOO). At the time of the survey the eddy core showed lowest oxygen concentrations of less than 5 μmol kg−1 and a pH of approx. 7.6 at the lower boundary of the euphotic zone. Correspondingly, the aragonite saturation level dropped to 1 thereby creating unfavorable conditions for calcifying organisms at this shallow depth. To our knowledge, such enhanced acidity within near-surface waters has never been reported before for the open Atlantic Ocean. Vertical distributions of particulate and dissolved organic matter (POM, DOM) generally show elevated concentrations in the surface mixed layer, but particularly DOM also accumulates beneath the oxygen minimum. Considering reference data from the upwelling region where these eddies are formed, we determined the oxygen consumption through remineralization of organic matter and found an enhancement of apparent oxygen utilization rates (aOUR, 0.26 μmol kg−1 d−1) by almost one order of magnitude when compared with typical values for the open North Atlantic. Computed downward fluxes for particulate organic carbon (POC) at 100 m were about 0.19 to 0.23 g C m−2 d−1 which clearly exceed fluxes typical for an oligotrophic open ocean setting. The observations support the view that the oxygen depleted eddies can be viewed as isolated, westwards propagating upwelling systems as their own.

scholarly journals Sedimentary supply of humic-like fluorescent dissolved organic matter and its implication for chemoautotrophic microbial activity in the Izu-Ogasawara Trench

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Shigemitsu ◽  
T. Yokokawa ◽  
H. Uchida ◽  
S. Kawagucci ◽  
A. Murata
Keyword(s):  
Organic Matter ◽  
Community Structure ◽  
Dissolved Organic Matter ◽  
Oxygen Utilization ◽  
Fluorescent Dissolved Organic Matter ◽  
Vertical Distributions ◽  
The Difference ◽  
The Relationship ◽  
Apparent Oxygen Utilization

AbstractMicrobial community structure in the hadal water is reported to be different from that in the upper abyssal water. However, the mechanism governing the difference has not been fully understood. In this study, we investigate the vertical distributions of humic-like fluorescent dissolved organic matter (FDOMH), chemoautotrophic production, apparent oxygen utilization (AOU), and N* in the Izu-Ogasawara Trench. In the upper abyssal waters (< 6000 m), FDOMH has a significantly positive correlation with AOU; FDOMH deviates from the relationship and increases with depth without involving the increment of AOU in the hadal waters. This suggests that FDOMH is transferred from the sediments to the hadal waters through pore water, while the FDOMH is produced in situ in the upper abyssal waters. Chemoautotrophic production and N* increases and decreases with depth in the hadal waters, respectively. This corroborates the effluxes of dissolved substances, including dissolved organic matter and electron donors from sediments, which fuels the heterotrophic/chemoautotrophic microbial communities in the hadal waters. A simple box model analysis reveals that the funnel-like trench topography facilitates the increase in dissolved substances with depth in the hadal waters, which might contribute to the unique microbiological community structure in these waters.

Numerical simulation and application of micro-nano bubble releaser for irrigation

2021 ◽  
Vol 11 (6) ◽  
pp. 1007-1015
Author(s):  
Yubin Zhang ◽  
Zhengying Wei ◽  
Jing Xu ◽  
Huafeng Wang ◽  
Huomei Zhu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Oxygen Concentration ◽  
Structural Parameters ◽  
Average Particle Size ◽  
Utilization Rate ◽  
Average Particle ◽  
Low Oxygen ◽  
Oxygen Utilization ◽  
Bubble Generation ◽  
Release Device

In oxygenated irrigation, there are problems of large oxygenated bubble particles, low oxygen concentration in water, and mismatch with current irrigation systems. In this paper, numerical simulation of micro-nano bubble releaser was carried out and the development of oxygenated irrigation equipment was studied. The release method of dissolved gas was selected to generate micro-nano bubbles after comparing different micro-nano bubble generation methods. The basic structure of the core-component releaser of generating micro-nano bubbles was initially determined. Effects of different structures of the release device on water aeration performance were studied by CFD analysis method. An optimal structure of the releaser was determined with orthogonal experiments based on a single factor experiment. The structural parameters included a throat of a 3 mm diameter, a 2 mm thick turbulent cavity, a six-degree exit angle, and two outlets. Optimal inlet and outlet pressure difference of the release device was 0.3 MPa. The bubble had an average particle size of 373.1 nm as measured. The release device was fabricated by 3D printing technology and the micro-nano bubble aeration irrigation device was developed. The system function test was carried out. Under the standard state, the performance parameters of the micro-nano bubble aerator included the maximum oxygen concentration of 11.4 mg/L, a total oxygen transfer coefficient of 0.4139 min-1, 0.0114 kg/h oxygenation capacity, and 60.81% oxygen utilization rate. The device had advantages of a high oxygen-increasing efficiency and a small volume, making it quite prospective in the field of oxygenated irrigation.

Host fruit as a suitable bacteria growth substrate that promotes larval development of Bactrocera dorsalis (Diptera: Tephritidae)

2019 ◽  
Author(s):  
Mazarin Akami ◽  
Xueming Ren ◽  
Yaohui Wang ◽  
Abdelaziz Mansour ◽  
Shuai Cao ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Microbial Communities ◽  
Larval Development ◽  
Bacterial Growth ◽  
Bacterial Community Structure ◽  
Fruit Fly ◽  
Bactrocera Dorsalis ◽  
Significant Shift ◽  
Bacteria Growth

AbstractThe ability of a host plant to act as a substrate or media for larval development may depend on how good it is at offering suitable nutrients for bacterial growth. In this study, we hypothesized that the suitability of a fruit type for fruit fly larval development is positively correlated with the ability of that fruit to act as a substrate/media for fruit fly symbiotic bacterial growth. We allowed a single female fruit fly to lay eggs on five different host fruits, then we monitored the larval development parameters across five generations and analyzed the bacterial community structure of larvae developing in 2 of these hosts (apple and banana) at the first and fifth generations. Results indicate that the larval length and dry weight did not vary significantly across experimental generations, but were greatly affected by fruit types and larval stages. The larval development time was extended considerably in apple and tomato but shortened in banana and mango. There was a significant shift in bacterial community structure and composition across fruits and generations. The bacterial community of larvae within the same fruit (apple and banana) clustered and was similar to the parental female (with the predominance of Proteobacteria), but there was a shift at the fifth generation (dominance of Firmicutes). Banana offered a suitable better development and growth to larvae and bacteria, respectively, compared to apple in which reduced larval development and bacterial growth were recorded. Although additional experiments are needed to adequately show that the differences in microbiome seen in fruit fly larval guts are the actual driver of different developmental outcomes of larvae on the different fruits, at the very least, our study has provided intriguing data suggesting interaction between the diets and gut microbial communities on insect development.Importance and Significance of the studyTephritid fruit flies entertain complex interactions with gut bacteria. These bacteria are known to provide nutritional benefits to their hosts, by supplementing missing nutrients from the host diets and regulating energy balance. Foraging for food is a risky exercise for the insect which is exposed to ecological adversities, including predators. Therefore, making beneficial choice among available food substrates is a question of survival for the flies and bacteria as well. Our study demonstrates interactions between the host fly and its intestinal bacteria in sustaining the larval development while foraging optimally on different fruit types. These findings add a novel step into our understanding of the interactions between the gut microbial communities and B. dorsalis and provide avenues for developing control strategies to limit the devastative incidence of the fly.

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