scholarly journals Long-Term Mootral Application Impacts Methane Production and the Microbial Community in the Rumen Simulation Technique System

2021 ◽  
Vol 12 ◽  
Author(s):  
Johanna Brede ◽  
Manuela Peukert ◽  
Björn Egert ◽  
Gerhard Breves ◽  
Melanie Brede
Keyword(s):  
Microbial Community ◽  
Relative Abundance ◽  
Methane Production ◽  
Solid Phase ◽  
Methane Emissions ◽  
Simulation Technique ◽  
Feed Additive ◽  
Gene Copy ◽  
Long Term Effects

Methane emissions by ruminants contribute to global warming and result in a loss of dietary energy for the animals. One possibility of reducing methane emissions is by dietary strategies. In the present trial, we investigated the long-term effects of Mootral, a feed additive consisting of garlic powder (Allium sativum) and bitter orange extracts (Citrus aurantium), on fermentation parameters and the microbial community in the rumen simulation technique (RUSITEC) system. The experiment lasted 38 days and was divided into three phases: an equilibration period of 7 days, a baseline period (BL) of 3 days, and experimental period (EP) of 28 days. Twelve fermentation vessels were divided into three groups (n = 4): control (CON), short-term (ST), and long-term (LT) application. From day 11 to day 27, 1.7 g of Mootral was added to the ST vessels; LT vessels received 1.7 g of Mootral daily for the entire EP. With the onset of Mootral application, methane production was significantly reduced in both groups until day 18. Thereafter, the production rate returned to the initial quantity. Furthermore, the short chain fatty acid fermentation profile was significantly altered by Mootral application; the molar proportion of acetate decreased, while the proportions of propionate and butyrate increased. Metabolomic analysis revealed further changes in metabolite concentrations associated with the Mootral supplementation period. The methyl coenzyme-M reductase gene copy number was reduced in the liquid and solid phase, whereas the treatment did not affect the abundance of bacteria. At the end of the BL, Methanomicrobia was the most abundant archaeal class. Mootral supplementation induced an increase in the relative abundance of Methanomassiliicoccales and a reduction in the relative abundance of Methanomicrobia, however, this effect was transient. Abundances of bacterial families were only marginally altered by the treatment. In conclusion, Mootral has the transient ability to reduce methane production significantly due to a selective effect on archaea numbers and archaeal community composition with little effect on the bacterial community.

IMMEDIATE AND LONG-TERM EFFECTS OF INSECTICIDE APPLICATION ON PARASITOIDS IN JACK PINE STANDS IN QUEBEC

1972 ◽  
Vol 104 (2) ◽  
pp. 263-270 ◽  
Author(s):  
Peter W. Price
Keyword(s):  
Relative Abundance ◽  
Jack Pine ◽  
Ground Vegetation ◽  
Long Term Effects ◽  
Aerial Application ◽  
Insecticide Application ◽  
Number Of Species ◽  
Adult Parasitoid ◽  
Pine Stands

AbstractParasitoid populations were sampled before, and for 4 years following, an aerial application of the insecticide phosphamidon to control a sawfly outbreak. Adult parasitoid mortality was high because of spraying, but a reservoir of parasitoids in host cocoons remained to repopulate the treated areas. In moister sites the number of species decreased and their relative abundance changed, but moderate numbers of parasitoids remained 4 years after spraying. In a dry site with little ground vegetation, none of the species present before spraying remained by the fourth year.

scholarly journals Historical land use has long-term effects on microbial community assembly processes in forest soils

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Ernest D. Osburn ◽  
Frank O. Aylward ◽  
J. E. Barrett
Keyword(s):  
Land Use ◽  
Microbial Community ◽  
Community Assembly ◽  
Soil Microbial Communities ◽  
Fungal Communities ◽  
Long Term Effects ◽  
Soil Microbial ◽  
Historical Land Use ◽  
Microbial Community Assembly

AbstractLand use change has long-term effects on the structure of soil microbial communities, but the specific community assembly processes underlying these effects have not been identified. To investigate effects of historical land use on microbial community assembly, we sampled soils from several currently forested watersheds representing different historical land management regimes (e.g., undisturbed reference, logged, converted to agriculture). We characterized bacterial and fungal communities using amplicon sequencing and used a null model approach to quantify the relative importance of selection, dispersal, and drift processes on bacterial and fungal community assembly. We found that bacterial communities were structured by both selection and neutral (i.e., dispersal and drift) processes, while fungal communities were structured primarily by neutral processes. For both bacterial and fungal communities, selection was more important in historically disturbed soils compared with adjacent undisturbed sites, while dispersal processes were more important in undisturbed soils. Variation partitioning identified the drivers of selection to be changes in vegetation communities and soil properties (i.e., soil N availability) that occur following forest disturbance. Overall, this study casts new light on the effects of historical land use on soil microbial communities by identifying specific environmental factors that drive changes in community assembly.

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

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.

A single application of fertiliser or manure to a cropping field has limited long-term effects on soil microbial communities

Soil Research ◽  
2019 ◽  
Vol 57 (3) ◽  
pp. 228
Author(s):  
C. Celestina ◽  
P. W. G. Sale ◽  
J. R. Hunt ◽  
C. Tang ◽  
A. E. Franks
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Soil Microbial Community ◽  
Poultry Litter ◽  
Fungal Communities ◽  
Single Application ◽  
Long Term Effects ◽  
Soil Microbial Community Structure ◽  
Soil Microbial

A large-scale field experiment was used to investigate the long-term effects of a single application of manure or inorganic fertiliser on microbial communities in the topsoil and subsoil of a cropping field in south-west Victoria. Poultry litter (20 t ha–1) and fertiliser (with equivalent total nutrients to the manure) was either surface broadcast or deep ripped into the subsoil before sowing in 2014. Soil samples were collected from the 0–10 and 25–40cm horizons in each treatment immediately after harvest of the third successive crop in January 2017. Next-generation sequencing of the 16S and ITS rRNA genes was used to characterise the bacterial and fungal communities in the soil. Amendment type and method of placement had a limited effect on soil microbial community structure and diversity, three years after treatments were applied. Fungal communities exhibited weak responses to the poultry litter and fertiliser in comparison to a nil control, but none of the treatments had any detectable effect on bacterial communities. Differences in structure and diversity of microbial communities were overwhelmingly due to their vertical distribution in the soil profile, and not the application of different amendments to the soil by deep ripping or surface broadcasting. The strength and timing of the soil disturbance, plant selection effects and farm management history likely contributed to the lack of measurable response in the soil microbial community.

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