The structure of anammox granular sludge under varying long-term organic matter stress: Performance, physiochemical and microbial community

<p>The type of soil organic amendment selected can have profound implications for carbon cycling processes in soils. Understanding the link between this choice and its effect on the soil microbiome will improve our understanding of the capacity of these materials to improve carbon sequestration and cycling dynamics. Understanding and facilitating the lifestyle strategies of microorganisms processing organic matter is essential to improving our understanding of the terrestrial carbon cycle. This research focuses on utilising organic amendments to alter the indigenous soil microbial community composition and function to improve the capacity of the soil to cycle and store carbon in horticultural soils. &#160;The effects of annual application of various organic fertilisers (peat, bracken, bark, horse manure, garden compost) in a long-term (10year) field experiment were explored. Sampling was completed pre and post application of organic matter within one season (following 10 years of applications) to identify which organic amendment was more effective in producing benefits to plants through improved soil organic matter and which amendments provide the greatest legacy effect on carbon cycling. The response of the soil microbial community composition (phospholipid fatty acid analysis) and carbon functional cycling dynamics (respiration using MicroResp&#8482;) were determined with a view to improving our understanding of the interaction between the materials applied and microbial processes. PCA of the MicroResp&#8482; data identified that all treatments had a different functional profile compared to the control[PM1]&#160; with peat being significantly different from all other treatments. Horse manure and bark differed significantly within a single growing season; prior and post organic matter addition in spring 2019. &#160;Microbial biomass measurements for garden compost and horse manure were significantly higher following organic matter addition compared to all other treatments and the control[PM2]&#160;.&#160; All treatments had a significant effect [PM3]&#160;on hot water extractable carbon and total carbon. Peat had a significantly different effect[PM4]&#160;, when compared to other treatments, on the soil PLFA profile and bark application significantly increased [PM5]&#160;the neutral lipid (NLFA) biomarker 16:1&#969;5. &#160;Bark and horse manure application both significantly increased PLFA fungal biomarker 18:2&#969;6,9. No significant differences were found between the fungal/bacterial ratios of the organic matter additions prior to being added to the soil. These findings show that altering the resources available to the soil microbial community has a significant impact on soil microbial community composition and microbially mediated carbon cycling functionality. Increasing our understanding of how soil functions are altered by land management decisions will enable better informed predictions of the long-term benefits of organic matter applications on carbon sequestration and cycling dynamics.</p>

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A predictive model for N2O production in anammox-granular sludge reactors: Combined effects of nitrite/ammonium ratio and organic matter concentration

Journal of Environmental Management ◽

10.1016/j.jenvman.2021.113295 ◽

2021 ◽

Vol 297 ◽

pp. 113295

Author(s):

T.D.S. Pereira ◽

R.H. Spindola ◽

C.A.B.S. Rabelo ◽

N.C. Silveira ◽

M.A.T. Adorno ◽

...

Keyword(s):

Organic Matter ◽

Predictive Model ◽

Granular Sludge ◽

Combined Effects ◽

N2o Production ◽

Organic Matter Concentration ◽

Matter Concentration ◽

Anammox Granular Sludge

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Stress-Responses of Performance and Microbial Community in Anaerobic Digestion System Under Long-Term Enrichment of Phenanthrene

10.3233/atde210322 ◽

2021 ◽

Author(s):

Yongsen Shi ◽

Chunli Xu ◽

Jingyi Li ◽

Yilin Yao ◽

Qigui Niu

Keyword(s):

Microbial Community ◽

Stress Responses ◽

System Performance ◽

Oxygen Demand ◽

Granular Sludge ◽

Long Term Effects ◽

Term Enrichment ◽

Fermentative Bacteria ◽

Soluble Chemical Oxygen Demand

The expanded granular sludge blanket reactor (EGSB) was operated for 198 days to study the long-term effects of phenanthrene (PHE) enrichment on system performance and microbial community. The results showed that the PHE was significantly enriched in the reactor. The final PHE concentration in effluent and sludge reached to 1.764±0.05 mg/L and 12.52±0.42 mg/gTS, respectively. While the average daily methane production was decreased by 5.0%-9.8% under long-term PHE exposure. The 3D-EEM of effluent indicated that PHE stimulated the microbial metabolism with the higher intensity of soluble microbial byproduct-like materials (SMP) and proteins. Moreover, the removal efficiency of soluble chemical oxygen demand (SCOD) and NH4+-N gradually diminished with the enrichment of PHE. PHE shaped the microbial community, and the predominant fermentative bacteria (Mesotoga) was severely inhibited. Contrarily, the bacteria (Syntrophorhabdus, Acinetobacter, Desulfovibrio, Desulfomicrobium) involved in PHE-degradation was enriched at end of Phase V. In addition, the relative abundance (RA) of hydrotrophic methanogens (Methanofastidiosum, Methanolinea, Methanobacterium, Methanomassiliicoccus) increased by 0.96-fold with the long-term enrichment of PHE, while the RA of acetoclastic Methanosaeta obviously decreased.

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