scholarly journals Genome-centric metagenomic insights into the impact of alkaline/acid and thermal sludge pre-treatment on digestion sludge microbiome

2020 ◽  
Author(s):  
Shanquan Wang ◽  
Zhiwei Liang ◽  
Jiangjian Shi ◽  
Chen Wang ◽  
Junhui Li ◽  
...  
Keyword(s):  
Organic Matter ◽  
Metabolic Potential ◽  
Floc Structure ◽  
Sludge Digestion ◽  
Fermentative Bacteria ◽  
Pre Treatment ◽  
The Impact ◽  
Carbohydrate Digestion ◽  
Metagenomic Approach ◽  
Insight Into

Abstract Background: Wastewater treatment generates large amounts of waste activated sludge (WAS), which mainly consist of recalcitrant microbial cells and particulate organic matter. WAS pre-treatment is an effective way to destabilize sludge floc structure and release cellular macromolecules and other organic matter for improvement of digestion efficiency. Nonetheless, impacts of WAS pre-treatment on the complex digestion sludge microbiome, as well as mechanistic insight into how sludge pre-treatment improve digestion performance, remain to be elucidated. Results: In this study, genome-centric metagenomic approach was employed to investigate the digestion sludge microbiome in four methanogenic sludge digesters with different feeding sludge: APAD, WAS pre-treated with 0.25 mol/L alkaline/acid; HS-APAD, WAS pre-treated with 0.8 mol/L alkaline/acid; Thermal-AD, thermal pre-treated WAS; Control-AD, fresh WAS. We retrieved 254 metagenomic-assembled genomes (MAGs) to identify the key functional populations involved in methanogenic digestion process. These MAGs span 28 phyla with 69 of them as yet-to-be-cultivated lineages, and 30 novel lineages were characterized with metabolic potential associated with hydrolysis and fermentation. Interestingly, functional populations involving carbohydrate digestion were overrepresented in APAD and HS-APAD, while lineages related to protein and lipid fermentation were overrepresented in Thermal-AD, reflecting different digestion substrates released from alkaline/acid and thermal pre-treatments. Of the three major functional populations, i.e., fermentative bacteria, acetogenic syntrophs and methanogens, significant correlations between genome sizes of the fermentative bacteria and their abundance were observed, particularly in the APAD and HS-APAD with improved digestion performance. Conclusion: These genome-centric metagenomic insights advance our understanding of sludge pre-treatment on digestion sludge microbiomes, shedding light on future optimization of methanogenic sludge digestion and resource recovery.

scholarly journals Genome-Centric Metagenomic Insights into the Impact of Alkaline/Acid and Thermal Sludge Pretreatment on the Microbiome in Digestion Sludge

2020 ◽  
Vol 86 (23) ◽  
Author(s):  
Zhiwei Liang ◽  
Jiangjian Shi ◽  
Chen Wang ◽  
Junhui Li ◽  
Dawei Liang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Metabolic Networks ◽  
Waste Activated Sludge ◽  
Metabolic Potential ◽  
Sludge Digestion ◽  
Sludge Pretreatment ◽  
A Genome ◽  
Unique Source ◽  
The Impact

ABSTRACT Pretreatment of waste-activated sludge (WAS) is an effective way to destabilize sludge floc structure and release organic matter for improving sludge digestion efficiency. Nonetheless, information on the impact of WAS pretreatment on digestion sludge microbiomes, as well as mechanistic insights into how sludge pretreatment improves digestion performance, remains elusive. In this study, a genome-centric metagenomic approach was employed to investigate the digestion sludge microbiome in four sludge digesters with different types of feeding sludge: WAS pretreated with 0.25 mol/liter alkaline/acid (APAD), WAS pretreated with 0.8 mol/liter alkaline/acid (HS-APAD), thermally pretreated WAS (thermal-AD), and fresh WAS (control-AD). We retrieved 254 metagenome-assembled genomes (MAGs) to identify the key functional populations involved in the methanogenic digestion process. These MAGs span 28 phyla, including 69 yet-to-be-cultivated lineages, and 30 novel lineages were characterized with metabolic potential associated with hydrolysis and fermentation. Interestingly, functional populations involving carbohydrate digestion were enriched in APAD and HS-APAD, while lineages related to protein and lipid fermentation were enriched in thermal-AD, corroborating the idea that different substrates are released from alkaline/acid and thermal pretreatments. Among the major functional populations (i.e., fermenters, syntrophic acetogens, and methanogens), significant correlations between genome sizes and abundance of the fermenters were observed, particularly in APAD and HS-APAD, which had improved digestion performance. IMPORTANCE Wastewater treatment generates large amounts of waste-activated sludge (WAS), which consists mainly of recalcitrant microbial cells and particulate organic matter. Though WAS pretreatment is an effective way to release sludge organic matter for subsequent digestion, detailed information on the impact of the sludge pretreatment on the digestion sludge microbiome remains scarce. Our study provides unprecedented genome-centric metagenomic insights into how WAS pretreatments change the digestion sludge microbiomes, as well as their metabolic networks. Moreover, digestion sludge microbiomes could be a unique source for exploring microbial dark matter. These results may inform future optimization of methanogenic sludge digestion and resource recovery.

scholarly journals Metabolic Diversity within the Globally Abundant Marine Group IIEuryarchaeaOffers Insight into Ecological Patterns

2018 ◽  
Author(s):  
Benjamin J Tully
Keyword(s):  
Organic Matter ◽  
Genomic Analysis ◽  
Comparative Genomic Analysis ◽  
Comparative Genomic ◽  
Metabolic Diversity ◽  
Metabolic Potential ◽  
Surface Ocean ◽  
Ecological Patterns ◽  
Reference Genomes ◽  
Insight Into

AbstractDespite their discovery over 25 years ago, the Marine Group IIEuryarchaea(MGII) have remained a difficult group of organisms to study, lacking cultured isolates and genome references. The MGII have been identified in marine samples from around the world and evidence supports a photoheterotrophic lifestyle combining phototrophy via proteorhodopsins with the remineralization of high molecular weight organic matter. Divided between two clades, the MGII have distinct ecological patterns that are not understood based on the limited number of available genomes. Here, I present the comparative genomic analysis of 250 MGII genomes, providing the most detailed view of these mesophilic archaea to-date. This analysis identified 17 distinct subclades including nine subclades that previously lacked reference genomes. The metabolic potential and distribution of the MGII genera revealed distinct roles in the environment, identifying algal-saccharide-degrading coastal subclades, protein-degrading oligotrophic surface ocean subclades, and mesopelagic subclades lacking proteorhodopsins common in all other subclades. This study redefines the MGII and provides an avenue for understanding the role these organisms play in the cycling of organic matter throughout the water column.

Reducing the effect of cyanobacteria in the microfiltration of secondary effluent

2010 ◽  
Vol 62 (7) ◽  
pp. 1682-1688 ◽  
Author(s):  
Y. T. Goh ◽  
J. L. Harris ◽  
F. A. Roddick
Keyword(s):  
Organic Matter ◽  
Sewage Treatment ◽  
Cyanobacterial Blooms ◽  
Secondary Effluent ◽  
Dissolved Air Flotation ◽  
Algal Organic Matter ◽  
Alum Coagulation ◽  
Pre Treatment ◽  
The Impact ◽  
Dissolved Air

Cyanobacterial blooms in the lagoons of sewage treatment plants can severely impact the performance of membrane plants treating the effluent. This paper investigates the impact of Microcystis aeruginosa in a secondary effluent on the microfiltration filterability and cleaning of the membrane. Alum coagulation and dissolved air flotation (DAF) were investigated to remove the algae and so enhance the volume of effluent processed, and their influence on reversible and irreversible fouling. Degree of fouling due to the algal components was found to be in decreasing order of algal cells, algal organic matter and extracellular organic matter. Alum coagulation with 5 mg L−1 as Al3 +  led to a substantial increase in permeate volume, an increase in dissolved organic carbon removal, and a foulant layer which protected the membrane from internal fouling but which was hydraulically removable resulting in full flux recovery. Pre-treatment by DAF or 1.5 μm filtration following alum coagulation enhanced the flux rate and permeate volume but exposed the membrane to internal irreversible fouling.

scholarly journals Potential Mechanisms for Microbial Energy Acquisition in Oxic Deep-Sea Sediments

2016 ◽  
Vol 82 (14) ◽  
pp. 4232-4243 ◽  
Author(s):  
Benjamin J. Tully ◽  
John F. Heidelberg
Keyword(s):  
Organic Matter ◽  
Microbial Community ◽  
Deep Sea ◽  
Carbon Fixation ◽  
Metabolic Potential ◽  
Manganese Oxidation ◽  
Content Type ◽  
Deep Sea Sediments ◽  
Iron Manganese ◽  
Insight Into

ABSTRACTThe South Pacific Gyre (SPG) possesses the lowest rates of sedimentation, surface chlorophyll concentration, and primary productivity in the global oceans. As a direct result, deep-sea sediments are thin and contain small amounts of labile organic carbon. It was recently shown that the entire SPG sediment column is oxygenated and may be representative of up to a third of the global marine environment. To understand the microbial processes that contribute to the removal of the labile organic matter at the water-sediment interface, a sediment sample was collected and subjected to metagenomic sequencing and analyses. Analysis of nine partially reconstructed environmental genomes, which represent approximately one-third of the microbial community, revealed that the members of the SPG surface sediment microbial community are phylogenetically distinct from surface/upper-ocean organisms. These genomes represent a wide distribution of novel organisms, including deep-branchingAlphaproteobacteria, two novel organisms within theProteobacteria, and new members of theNitrospirae,Nitrospinae, and candidate phylum NC10. These genomes contain evidence for microbially mediated metal (iron/manganese) oxidation and carbon fixation linked to nitrification. Additionally, despite hypothesized energy limitation, members of the SPG microbial community had motility and chemotaxis genes and possessed mechanisms for the degradation of high-molecular-weight organic matter. This study contributes to our understanding of the metabolic potential of microorganisms in deep-sea oligotrophic sediments and their impact on local carbon geochemistry.IMPORTANCEThis research provides insight into the microbial metabolic potential of organisms inhabiting oxygenated deep-sea marine sediments. Current estimates suggest that these environments account for up to a third of the global marine sediment habitat. Nine novel deep-sea microbial genomes were reconstructed from a metagenomic data set and expand the limited number of environmental genomes from deep-sea sediment environments. This research provides phylogeny-linked insight into critical metabolisms, including carbon fixation associated with nitrification, which is assignable to members of the marine group 1Thaumarchaeota,Nitrospinae, andNitrospiraeand neutrophilic metal (iron/manganese) oxidation assignable to a novel proteobacterium.

scholarly journals Erythroid precursors and progenitors suppress adaptive immunity and get invaded by SARS-CoV-2

2020 ◽  
Author(s):  
Shima Shahbaz ◽  
Lai Xu ◽  
Mohammad Osman ◽  
Wendy Sligl ◽  
Justin Shields ◽  
...  
Keyword(s):  
Blood Circulation ◽  
Blood Oxygen ◽  
Erythroid Cells ◽  
Erythroid Progenitors ◽  
Stress Erythropoiesis ◽  
Lower Blood ◽  
Erythroid Precursors ◽  
Pre Treatment ◽  
The Impact ◽  
Insight Into

AbstractSARS-CoV-2 infection is associated with lower blood oxygen levels even in patients without hypoxia requiring hospitalization. This discordance illustrates the need for a more unifying explanation as to whether SARS-CoV-2 directly or indirectly affects erythropoiesis. Here we show significantly enriched CD71+ erythroid precursors/progenitors in the blood circulation of COVID-19 patients that have distinctive immunosuppressive properties. A subpopulation of abundant erythroid cells, CD45+CD71+cells, co-express ACE2, TMPRSS2, CD147, CD26 and these can be infected with SARS-CoV-2. In turn, pre-treatment of erythroid cells with dexamethasone significantly diminished ACE2/TMPRSS2 expression and subsequently reduced their infectivity with SARS-CoV-2. Taken together, pathological abundance of erythroid cells might reflect stress erythropoiesis due to the invasion of erythroid progenitors by SARS-CoV-2. This may provide a novel insight into the impact of SARS-CoV-2 on erythropoiesis and hypoxia seen in COVID-19 patients.

scholarly journals Effects of Rotations With Legume on Soil Functional Microbial Communities Involved in Phosphorus Transformation

2021 ◽  
Vol 12 ◽  
Author(s):  
Hui Yu ◽  
Fenghua Wang ◽  
Minmin Shao ◽  
Ling Huang ◽  
Yangyang Xie ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Soil Microbial Communities ◽  
Soil Microbial ◽  
P Cycling ◽  
P Transformation ◽  
Microbial P ◽  
The Impact ◽  
Metagenomic Approach ◽  
Insight Into ◽  
Phosphorus Transformation

Including legumes in the cereal cropping could improve the crop yield and the uptake of nitrogen (N) and phosphorus (P) of subsequent cereals. The effects of legume-cereal crop rotations on the soil microbial community have been studied in recent years, the impact on soil functional genes especially involved in P cycling is raising great concerns. The metagenomic approach was used to investigate the impacts of crop rotation managements of soybean-wheat (SW) and maize-wheat (MW) lasting 2 and 7years on soil microbial communities and genes involved in P transformation in a field experiment. Results indicated that SW rotation increased the relative abundances of Firmicutes and Bacteroidetes, reduced Actinobacteria, Verrucomicrobia, and Chloroflexi compared to MW rotation. gcd, phoR, phoD, and ppx predominated in genes involved in P transformation in both rotations. Genes of gcd, ppa, and ugpABCE showed higher abundances in SW rotation than in MW rotation, whereas gadAC and pstS showed less abundances. Proteobacteria, Acidobacteria, and Gemmatimonadetes played predominant roles in microbial P cycling. Our study provides a novel insight into crop P, which requires strategy and help to understand the mechanism of improving crop nutrient uptake and productivity in different rotations.

Aromatic hydrocarbons provide new insight into carbonate concretion formation and the impact of eogenesis on organic matter

2020 ◽  
Vol 143 ◽  
pp. 103961
Author(s):  
C. Plet ◽  
K. Grice ◽  
A.G. Scarlett ◽  
W. Ruebsam ◽  
A.I. Holman ◽  
...  
Keyword(s):  
Organic Matter ◽  
Aromatic Hydrocarbons ◽  
Carbonate Concretion ◽  
The Impact ◽  
Insight Into

The impact of urban effluents on the coastal marine environment of Mediterranean islands

1995 ◽  
Vol 32 (9-10) ◽  
pp. 85-94 ◽  
Author(s):  
Michael O. Angelidis
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Marine Environment ◽  
Suspended Particle ◽  
Pollution Source ◽  
Mediterranean Islands ◽  
Coastal Marine Environment ◽  
Coastal Marine ◽  
The Impact ◽  
The City

The impact of the urban effluents of Mytilene (Lesvos island, Greece) on the receiving coastal marine environment, was evaluated by studying the quality of the city effluents (BOD5, COD, SS, heavy metals) and the marine sediments (grain size, organic matter, heavy metals). It was found that the urban effluents of Mytilene contain high organic matter and suspended particle load because of septage discharge into the sewerage network. Furthermore, although the city does not host important industrial activity, its effluents contain appreciable metal load, which is mainly associated with the particulate phase. The city effluents are discharged into the coastal marine environment and their colloidal and particulate matter after flocculation settles to the bottom, where is incorporated into the sediments. Over the years, the accumulation of organic matter and metals into the harbour mud has created a non-point pollution source in the relatively non-polluted coastal marine environment of the island. Copper and Zn were the metals which presented the higher enrichment in the sediments of the inner harbour of Mytilene.

Fish farming in Denmark: environmental impact of regulative legislation

1995 ◽  
Vol 31 (10) ◽  
pp. 73-84 ◽  
Author(s):  
T. M. Iversen
Keyword(s):  
Organic Matter ◽  
Environmental Impact ◽  
Freshwater Fish ◽  
Aquatic Environment ◽  
Action Plan ◽  
Fish Farming ◽  
Fish Farms ◽  
Nitrogen And Phosphorus ◽  
Local Impact ◽  
The Impact

The main environmental problems associated with fish farming in Denmark are attributable to the dam, the “dead reach” and nutrient and organic matter discharge. The environmental regulation of fish farming in Denmark started with the Environmental Protection Act of 1974, the Statutory Order of 1985 forbidding wet feed, and the Action Plan on the Aquatic Environment of 1987. In the case of freshwater fish farms, the latter was implemented through the measures stipulated in the 1989 Statutory Order on Fish Farms. The impact of Danish legislative measures to reduce and regulate the environmental effects of freshwater fish farms can be summarized as follows: - the number of fish farms has been reduced from about 800 in 1974 to about 500 at present; - production has tripled since 1974 and has been stable since 1989; - a change from wet to dry feed has reduced the environmental impact of the farms; - the national goals of the Action Plan on the Aquatic Environment of 1987 for reducing fish farm discharges of organic matter, nitrogen and phosphorus have been fulfilled. The main remaining problems are that: - the local impact of fish farms on downstream stream quality is still much too high in about 15% of cases; - the problem of the passage of migrating invertebrates and fish is still unsolved at some farms; - the problems posed by “dead reaches” are still unsolved. It is concluded that sustainable fish farming is possible in Denmark, but with the present technology production will have to be significantly reduced.

Sign in / Sign up

Export Citation Format

Share Document