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 2018
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.
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
In July and August 2017, Dr. Jesus, his co-PI Dr. Iveraldo Dutra, and other team members visited three different municipalities—Boca do Acre (Amazonas State), Bujari (Acre State), and Manicoré (Amazonas State). They went to the field and examined the soil in order to choose sites with similar soil characteristics within each farm visited. However, this was not always possible due to specific characteristics of the farms, such as, for example, the existence of forests near some pastures. Two farms were sampled in Manicoré, with a forest and a pasture sampled on each. In Boca do Acre, they sampled two farms, with a forest and two pastures with different ages and management (reformed and not reformed) on each farm; Bujari was sampled this way as well. The farms in Manicoré present a contrast to farms in the other locations, as the pastures had been burned recently in Manicoré but not in the other municipalities. Also, the distribution of roots in the forest soils differed between sites, with a more defined root distribution in Manicoré. Soils visually differed between farms and even within farms. The team took samples at different horizons when necessary, including L (litter) and H (root) horizons in the forests, as well as layers containing charcoal in the pastures. They took this approach in order to consider specificities of each environment in their future comparisons. In addition, rhizosphere samples were taken from both land-use systems (forest and pasture) for additional analyses with primers for Actinobacteria. They researchers subjected the soil samples to physical and chemical analyses, and this work is still ongoing as of October 2017. DNA extraction is also under way in preparation for sequencing, and the extraction process should be complete by the end of the year. The DNA samples will be sequenced at Argonne National Lab. Dr. Lucy Seldin of UFRJ will help with the analysis of Actinobacteria through molecular methods, and Dr. Iveraldo and his postdoc Dr. Aline Oliveira will work on the characterization of animal biota.
In late April, Dr. Jesus was awarded supplemental PEER funds to organize a training workshop in Brazil to be led by U.S. partner Dr. James Cole of Michigan State University and two colleagues, Dr. Adina Chuang Howe of Iowa State University and Dr. Kostas Konstantinidis of Georgia Tech. This workshop will be held during the third week of October 2017 at The National Laboratory for Scientific Computing in Petrópolis.
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