scholarly journals The Impact of Long-Term Nitrogen Addition on Microbial Community Composition in Three Hawaiian Forest Soils

2001 ◽  
Vol 1 ◽  
pp. 500-504 ◽  
Author(s):  
Teri C. Balser
Keyword(s):  
Microbial Community ◽  
Community Composition ◽  
Forest Soils ◽  
Microbial Community Composition ◽  
Natural Fertility ◽  
Soil Parameters ◽  
N Addition ◽  
A Site ◽  
The Impact

We evaluated the microbial communities in three Hawaiian forest soils along a natural fertility gradient and compared their distinct responses to long-term nitrogen (N) additions. The sites studied have the same elevation, climate, and dominant vegetation, but vary in age of development, and thus in soil nutrient availability and nutrient limitation to plant growth. Fertilized plots at each site have received 100 kg ha year-1N addition for at least 8 years. Soil parameters, water content, pH, and ammonium and nitrate availability differed by site, but not between control and N-addition treatments within a site at the time of sampling. Microbial biomass also varied by site, but was not affected by N addition. In contrast, microbial community composition (measured by phospholipid analysis) varied among sites and between control and N-addition plots within a site. These data suggest that microbial community composition responds to N addition even when plant net primary productivity is limited by nutrients other than N. This may have implications for the behavior of forests impacted by atmospheric N deposition that are considered to be “nitrogen saturated,” yet still retain N in the soil.

scholarly journals The impact of immigration on microbial community composition in full-scale anaerobic digesters

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Rasmus H. Kirkegaard ◽  
Simon J. McIlroy ◽  
Jannie M. Kristensen ◽  
Marta Nierychlo ◽  
Søren M. Karst ◽  
...  
Keyword(s):  
Microbial Community ◽  
Community Composition ◽  
Microbial Community Composition ◽  
Full Scale ◽  
Anaerobic Digesters ◽  
The Impact

Analysis of Broad-scale Differences in Microbial Community Composition of Two Pristine Forest Soils

1998 ◽  
Vol 21 (4) ◽  
pp. 579-587 ◽  
Author(s):  
Antonis Chatzinotas ◽  
Ruth-Anne Sandaa ◽  
Wilhelm Schönhuber ◽  
Rudolf Amann ◽  
Frida Lise Daae ◽  
...  
Keyword(s):  
Microbial Community ◽  
Community Composition ◽  
Forest Soils ◽  
Microbial Community Composition ◽  
Pristine Forest ◽  
Broad Scale

scholarly journals PSI-10 Establishing a foundation to harvest the potential of the microbiome in poultry production

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 293-294
Author(s):  
Camila S Marcolla ◽  
Benjamin Willing
Keyword(s):  
Microbial Community ◽  
Gut Microbiota ◽  
Community Composition ◽  
Relative Abundance ◽  
Microbial Community Composition ◽  
Alpha Diversity ◽  
Poultry Production ◽  
Microbiota Composition ◽  
Microbial Composition ◽  
The Impact

Abstract This study aimed to characterize poultry microbiota composition in commercial farms using 16S rRNA sequencing. Animals raised in sanitized environments have lower survival rates when facing pathogenic challenges compared to animals naturally exposed to commensal organisms. We hypothesized that intensive rearing practices inadvertently impair chicken exposure to microbes and the establishment of a balanced gut microbiota. We compared gut microbiota composition of broilers (n = 78) and layers (n = 20) from different systems, including commercial intensive farms with and without in-feed antibiotics, organic free-range farms, backyard-raised chickens and chickens in an experimental farm. Microbial community composition of conventionally raised broilers was significantly different from antibiotic-free broilers (P = 0.012), from broilers raised outdoors (P = 0.048) and in an experimental farm (P = 0.006) (Fig1). Significant community composition differences were observed between antibiotic-fed and antibiotic-free chickens (Fig2). Antibiotic-free chickens presented higher alpha-diversity, higher relative abundance of Deferribacteres, Fusobacteria, Bacteroidetes and Actinobacteria, and lower relative abundance of Firmicutes, Clostridiales and Enterobacteriales than antibiotic-fed chickens (P < 0.001) (Fig3). Microbial community composition significantly changed as birds aged. In experimental farm, microbial community composition was significant different for 7, 21 and 35 day old broilers (P < 0.001), and alpha diversity increased from 7 to 21d (P < 0.024), but not from 21 to 35d; whereas, in organic systems, increases in alpha-diversity were observed from 7d to 21d, and from 21d to 35d (P < 0.05). Broilers and layers raised together showed no differences in microbiota composition and alpha diversity (P > 0.8). It is concluded that production practices consistently impact microbial composition, and that antibiotics significantly reduces microbial diversity. We are now exploring the impact of differential colonization in a controlled setting, to determine the impact of the microbes associated with extensively raised chickens. This study will support future research and the development of methods to isolate and introduce beneficial microbes to commercial systems.

Organic matter additions to soil and effects on microbially mediated carbon cycling

2020 ◽  
Author(s):  
Rachel hasler ◽  
Mark pawlett ◽  
Jim harris ◽  
Helen bostock ◽  
Marc redmile-gordon
Keyword(s):  
Organic Matter ◽  
Microbial Community ◽  
Carbon Cycling ◽  
Community Composition ◽  
Soil Microbial Community ◽  
Microbial Community Composition ◽  
Soil Microbial ◽  
Horse Manure ◽  
Soil Microbial Community Composition

<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.  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™) were determined with a view to improving our understanding of the interaction between the materials applied and microbial processes. PCA of the MicroResp™ data identified that all treatments had a different functional profile compared to the control[PM1]  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.  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] .  All treatments had a significant effect [PM3] on hot water extractable carbon and total carbon. Peat had a significantly different effect[PM4] , when compared to other treatments, on the soil PLFA profile and bark application significantly increased [PM5] the neutral lipid (NLFA) biomarker 16:1ω5.  Bark and horse manure application both significantly increased PLFA fungal biomarker 18:2ω6,9. 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>

scholarly journals Impacts of near‑future ocean warming on microbial community composition of the stomach of the soft‑bottom sea star Luidia clathrata (Say) (Echinodermata: Asteroidea)

2021 ◽  
Author(s):  
Michelle D Curtis ◽  
Casey D Morrow ◽  
James B McClintock
Keyword(s):  
Microbial Community ◽  
Community Composition ◽  
Seawater Temperature ◽  
Microbial Community Composition ◽  
Experimental Temperature ◽  
Sea Star ◽  
Soft Bottom ◽  
Cardiac Stomach ◽  
Luidia Clathrata ◽  
The Impact

Abstract There is growing evidence that environmental changes caused by climate change can impact the microbiome of marine invertebrates. Such changes can have important implications for the overall health of the host. In the present study we investigated the impact of chronic exposure to an ambient (28°C) and a predicted mid- (30°C) and end-of-century (32°C) seawater temperature on microbiome modification in tissues of the cardiac stomach of the abundant predatory sea star Luidia clathrata collected in September 2018 from Apalachee Bay, Florida (29°58’N, 84°19’W) in the northern Gulf of Mexico (GOM). Diversity (Shannon index) was lowest among the microbial community of stomach tissue when compared to the microbiome of the artificial sea star feed, and aquarium sand and seawater across all three experimental temperature treatments. Moreover, the stomach microbial community composition was distinct between each of the four sample types. Exposure to the highest experimental temperature treatment (32°C) resulted in a significant modification of the composition of the microbial community in stomach and sand samples, but not in seawater samples when compared to those from the current mean ambient GOM temperature (28°C). Importantly, at the most elevated temperature the stomach microbiome shifted from a Vibrio sp. dominated community to a more diverse community with higher proportions of additional taxa including Delftia sp. and Pseudomonas sp. This microbiome shift could impact the digestive functionality and ultimately the health of L. clathrata, a key soft-bottom predator in the northern GOM.

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