Cycle 4 (2015 Deadline)
Monitoring the disturbance of the microbiota in Amazonian soils during conversion of forest to pasture and its consequences on cattle health
PI: Ederson Jesus (firstname.lastname@example.org), Embrapa (Brazilian Corporation of Agricultural Research)
U.S. Partner: James Cole, Michigan State University
Project Dates: October 2015 - September 2019
Pandemics of “swollen face,” a bacterial-origin periodontitis disease afflicting ruminant livestock, have been correlated with deforested areas in Brazil (Döbereiner et al., 2000). This disease, which is also known as "lumpy face," was commonly reported in Brazil during the 1960s and 1980s. New cases have recently been observed in sheep and goat flocks in the Amazon, under the same epidemiological conditions and with the same characteristics observed in bovines. In such circumstances, the disease has destroyed herds of livestock, often up to 90% of the animals. Dr. Jesus and his project collaborators hypothesize a link between the “swollen face” disease and shifts in the soil microbial communities as a consequence of deforestation and pasture introduction. This belief is based on previous evidence showing that this disease is triggered by deforestation, which in turn leads to significant changes in the soil communities, favoring specific populations such as actinomycetes. The team’s objective is to characterize correlations between the soil environment, changes in the microbial community due to deforestation, and the occurrence of this disease. Once more specific correlations are identified, they will experimentally test hypotheses (e.g., causation) generated through isolating key microbes and using culture-dependent and independent techniques. Answering these questions is important to advance towards a cure for the disease and design monitoring methods and alternative management to reduce its incidence. Additionally, confirming the link between the occurrence of diseases, deforestation, and changes in biodiversity will contribute to the delineation of policies to hinder deforestation and to promote biodiversity conservation. As part of the effort, the U.S. Government-supported partner, Dr. James Cole, will provide training and support with bioinformatic analysis of the datasets, sharing analytical tools he uses in his own research.
|Dr. Jesus (left) with U.S. partner Dr. James Cole of Michigan State University and Dr. Kostas Konstantinidis from Georgia Tech, along with a third U.S. partner, Dr. Adina Howe of Iowa State University at the MiGA workshop (photo courtesy of Dr. Jesus).|
The world’s growing population and their increasing demand for animal protein raises concerns over the pressure for the creation of new pastures to meet this demand, especially in countries like Brazil, which is the world’s leading beef exporter. New pastures are created at the expense of native lands, including the Brazilian Amazon. In fact, pasture introduction is the major driver of deforestation in the region, and alternatives to reduce this pressure are needed. Within this context, this project can contribute with information to support policymakers in their decisions, as well as to create alternatives to the sustainable management of pre-existing pasture lands. The results of this project may also contribute to designing sustainable, innovative management systems, such as the integrated crop-livestock-forest system, which has been recognized by FAO, the Ministry of Agriculture of Brazil, and Embrapa as an alternative to stimulate the use of pre-existing pasture lands, guarantee food and agricultural security, and discourage the deforestation of new areas for agriculture and livestock production.
Summary of Recent Activities
From July 2 to 12, 2018, Dr. Jesus and his colleagues made a field visit to Boca do Acre (AM) and Bujari (AC), where they revisited the same farms they had sampled in 2017. They opened a total of nine trenches to characterize the soil profile at various layers, sampling three horizons in each profile to determine the soil water content and soil density. These samples were sent to Embrapa Amazonia Ocidental for analysis. The team also noted their descriptions of the various soils found during the field work, taking into consideration attributes such as color, texture, consistency, pore and root distribution, and biological activity, among others, taking other soil samples for further testing. These have been sent to the Soil Analysis Laboratory of Embrapa Solos for physical and chemical analyses. Meanwhile, they also took soil and litter samples for a detailed microbiological characterization of the studied environments, collecting 12 samples along a transect in each of the pastures and forests visited. The researchers sampled a total of 108 points in all farms, and at least three soil and litter layers were collected at each point.
DNA extracted from samples they collected in 2017 were sent to the Argonne National Laboratory for sequencing of the 16S rRNA gene. Dr. Jesus and his group received the sequencing results in late August and September 2018 and they are currently analyzing the data with the help of their USG partner. Their last trip to characterize soils will take place in November 2018. They will work on data analysis regarding their first stage results in the remaining months of this year, and they expect to have the results in manuscript format for publication early in 2019. At that time they also will start the field experiment for the second stage of the project, which involves studying the development of the disease in managed pastures. Samples will be taken for sequencing and to monitor specific bacterial groups during the course of the experiment, which will take 6-10 months of field work. Soil characterization of the experimental area will also be performed.
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