Testing sustained soil-to-soil contact as an approach for limiting the abiotic influence of source soils during experimental microbiome transfer

2019 ◽  
Vol 366 (19) ◽  
Author(s):  
Ryan V Trexler ◽  
Terrence H Bell

ABSTRACT Experimental separation of the biotic and abiotic components of soil will help in understanding the role of taxonomy and composition in soil microbiome function. The most common approach to soil microbiome transfer involves direct dilution of a non-sterile source soil into sterile recipient soils, introducing both microorganisms and soil compounds, leaving abiotic and biotic factors confounded. Here, we contrast microbiome transfer into sterile recipient soils through (i) direct soil transfer at two dilutions and (ii) a new approach, sustained contact between source and recipient soils. Sustained soil-to-soil contact retains separation between source and recipient soils, allows for multiple colonization events and increases confidence that microorganisms observed in recipient soils are active and growing. Each approach produced distinct microbiomes in recipient soils after 1 and 6 weeks of incubation, indicating that transfer method impacts microbial composition. The extent to which recipient microbiomes resembled source microbiomes varied by soil type, although in general, direct soil transfer appeared to most closely approximate source microbiomes. However, irrespective of transfer method, most bacterial sequences in recipient soils were from organisms transferred through all methods. We discuss the merits of each method for controlled soil microbiome studies.

2021 ◽  
Vol 9 (1) ◽  
pp. 148
Author(s):  
Marius Bredon ◽  
Elisabeth Depuydt ◽  
Lucas Brisson ◽  
Laurent Moulin ◽  
Ciriac Charles ◽  
...  

The crucial role of microbes in the evolution, development, health, and ecological interactions of multicellular organisms is now widely recognized in the holobiont concept. However, the structure and stability of microbiota are highly dependent on abiotic and biotic factors, especially in the gut, which can be colonized by transient bacteria depending on the host’s diet. We studied these impacts by manipulating the digestive microbiota of the detritivore Armadillidium vulgare and analyzing the consequences on its structure and function. Hosts were exposed to initial starvation and then were fed diets that varied the different components of lignocellulose. A total of 72 digestive microbiota were analyzed according to the type of the diet (standard or enriched in cellulose, lignin, or hemicellulose) and the period following dysbiosis. The results showed that microbiota from the hepatopancreas were very stable and resilient, while the most diverse and labile over time were found in the hindgut. Dysbiosis and selective diets may have affected the host fitness by altering the structure of the microbiota and its predicted functions. Overall, these modifications can therefore have effects not only on the holobiont, but also on the “eco-holobiont” conceptualization of macroorganisms.


2018 ◽  
Vol 43 (1) ◽  
pp. 24-45 ◽  
Author(s):  
Hannah R Miller ◽  
Stuart N Lane

Matthews’ 1992 geoecological model of vegetation succession within glacial forefields describes how following deglaciation the landscape evolves over time as the result of both biotic and abiotic factors, with the importance of each depending on the level of environmental stress within the system. We focus in this paper on how new understandings of abiotic factors and the potential for biogeomorphic feedbacks between abiotic and biotic factors makes further development of this model important. Disturbance and water dynamics are two abiotic factors that have been shown to create stress gradients that can drive early ecosystem succession. The subsequent establishment of microbial communities and vegetation can then result in biogeomorphic feedbacks via ecosystem engineering that influence the role of disturbance and water dynamics within the system. Microbes can act as ecosystem engineers by supplying nutrients (via remineralization of organic matter and nitrogen fixation), enhancing soil development, either decreasing (encouraging weathering) or increasing (binding sediment grains) geomorphic stability, and helping retain soil moisture. Vegetation can act as an ecosystem engineer by fixing nitrogen, enhancing soil development, modifying microbial community structure, creating seed banks, and increasing geomorphic stability. The feedbacks between vegetation and water dynamics in glacial forefields are still poorly studied. We propose a synthesized model of ecosystem succession within glacial forefields that combines Matthews’ initial geoecological model and Corenblit's model to illustrate how gradients in environmental stress combined with successional time drive the balance between abiotic and biotic factors and ultimately determine the successional stage and potential for biogeomorphic feedbacks.


Ecography ◽  
2016 ◽  
Vol 40 (4) ◽  
pp. 511-520 ◽  
Author(s):  
Clive T. Darwell ◽  
Kari A. Segraves ◽  
David M. Althoff

2017 ◽  
Vol 52 (2) ◽  
pp. 199-215 ◽  
Author(s):  
Estela Illa ◽  
Josep M. Ninot ◽  
Alba Anadon-Rosell ◽  
Francesc Oliva

2021 ◽  
Author(s):  
Emma Spencer ◽  
Thomas Newsome

ABSTRACT Dingoes (Canis dingo) are known for hunting and killing animals to meet their energetic requirements, but like almost all predators they also scavenge animal remains. To improve our understanding of dingo scavenging ecology, we investigated the role of abiotic and biotic factors in shaping carcass utilisation by dingoes and further determined whether dingo scavenging influenced carcass persistence in the landscape. To do so, we monitored visitation and scavenging by dingoes using remote cameras positioned on 119 kangaroo carcasses in open and closed canopy habitats and in warm and cool seasons. The carcasses were monitored across multiple study sites, which incorporated forest, alpine and desert ecoregions in Australia. We found that season played an important role in shaping carcass utilisation by dingoes, as well as carcass persistence. Warmer seasons increased the rate of carcass discovery 6.3-fold in the Forest study site and 4.8-fold in the Alpine study site, and also increased the time dingoes spent feeding on carcasses in the Alpine study site. Further, across all study sites, carcasses persisted at least 4.7 times longer in cool compared with warm seasons. On the other hand, carcass utilisation by dingoes was not influenced by habitat, although carcasses were more likely to persist in open compared with closed canopy habitats in the Alpine study site. Finally, our study showed that dingo scavenging may contribute to substantial carcass removal in certain contexts. Indeed, decreased carcass persistence in the Forest study site was evident in the cool season, when dingo scavenging occurred during the first two weeks of monitoring. The variability in results highlights the complexity of patterns in dingo scavenging and, more broadly, of vertebrate scavenging. It emphasises the need to consider multiple abiotic and biotic factors to properly understand the functional roles of different scavenger species. Longer-term studies with additional seasonal replicates may also yield a more detailed picture of the role of dingoes as apex scavengers.


1980 ◽  
Vol 58 (17) ◽  
pp. 1915-1922 ◽  
Author(s):  
J. C. Zak ◽  
D. T. Wicklow

The role of certain abiotic and biotic factors in determining the structure of a post-fire ascomycete community was studied by the laboratory simulation of soil conditions occurring during and following a prairie fire. Aerated steam treatment of prairie soil (35, 40, 55, 70, or 85 °C for 60 s) was used to simulate the elevated soil temperatures generated during a grassland fire. Further manipulations included: (1) addition of ashed remains of prairie grasses to steamed soil surfaces, (2) the incubation of steam-treated soil samples layered over untreated prairie soil, and (3) addition of ash to steamed soil underlain with a layer of untreated soil to create a simulated burn.Across all treatments, species diversity and total number of species were significantly higher in soils steamed at 35, 55, or 70 °C than soils steamed at 40 or 85 °C. The greatest number of species per sample for steaming alone occurred in samples treated at 55 °C. The addition of ash to steamed samples or layering with untreated prairie soil significantly reduced species diversity and total number of species as compared with steamed soil alone. When ash and a subsurface layer of untreated soil were applied together, species diversity, total number of species, and mean number of species for samples steamed at 55 or 70 °C, were significantly greater than when either treatment was added separately. It was found that a simulated burn at 55 or 70 °C promoted the development of a community which most closely resembled a naturally occurring post-fire ascomycete community. This suggested that the structure of the post-fire ascomycete community was in part determined by (1) species responses to elevated soil temperatures, (2) ash deposition, and (3) biotic factors associated with the subsurface soil layers.


2021 ◽  
Author(s):  
Maria M. Borisova-Mubarakshina ◽  
Ilya A. Naydov ◽  
Daria V. Vetoshkina ◽  
Marina A. Kozuleva ◽  
Daria V. Vilyanen ◽  
...  

The present chapter describes the mechanisms of reactive oxygen species formation in photosynthetic reactions and the functional significance of reactive oxygen species as signal messengers in photosynthetic cells of plants. Attention is given to the acclimation mechanisms of higher plants to abiotic and biotic factors such as increased light, drought, soil salinity and colonization of plants by rhizosphere microorganisms. Special attention is paid to the reactions of reactive oxygen species with the components of the chloroplasts plastoquinone pool leading to production of hydrogen peroxide as a signal molecule, which is involved in acclimation of plants to these stress conditions. The chapter also presents the data demonstrating that regulation of the size of the light-harvesting antenna of photosystem II is one of the universal mechanisms of the structural and functional reorganization of the photosynthetic apparatus of higher plants exposed to the abiotic and biotic factors. These data were obtained for both model Arabidopsis (Arabidopsis thaliana) plants as well as for agricultural barley (Hordeum vulgare) plants. It is hypothesized that hydrogen peroxide, produced with involvement of the plastoquinone pool components, plays the role of a signaling molecule for regulation of the photosystem II antenna size in higher plants when environmental conditions change.


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