Location: Food and Feed Safety ResearchTitle: Microbial community functional change during vertebrate carrion decomposition Author
|Crippen, Tawni - Tc|
Submitted to: PLoS One
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/30/2013
Publication Date: 12/12/2013
Citation: Pechal, J.L., Crippen, T.L., Tarone, A.M., Lewis, A.J., Tomberlin, J.K., Benbow, M.E. 2013. Microbial community functional change during vertebrate carrion decomposition. PLoS One. 8:e79035. doi:10.1371/journal.pone.0079035. Interpretive Summary: Microorganisms play a vital role in the decomposition of organic matter, such as wastes, produced at confined animal feeding operations. They are instrumental in the breakdown of animal carcasses lost during production or disease outbreaks. The management of solid organic wastes, such as fecal sludge, spent litter, and carcasses, is vital because it can be a source of pathogen spread. However, little is known about what microbes do and how pathogens persist over the course of decay of such a resource. This study provides a description of the use of various carbon sources by microbes during carrion decomposition over different seasons, between years, and related to insect activity. Microbes were also identified using high-throughput genetic sequencing during one study. Overall, microbial carbon use increased throughout the decay process in spring, summer, and winter and decreased in autumn. There was variability in the microbe carbon utilization in association with insect colonizers. These data are important in understanding the influence of microbes on the essential ecosystem process of carrion decomposition. Such information can be used to manipulate bacterial and insect communities to accelerate decomposition and limit pathogen spread.
Technical Abstract: Microorganisms play a critical role in the decomposition of organic matter, which contributes to energy and nutrient transformation in every ecosystem, yet little is known about the functional activity of epinecrotic microbial communities associated with carrion. The objective of this study was to provide a description of the carrion-associated microbial community functional activity using differential carbon source use throughout decomposition over seasons, between years, and when microbial communities were isolated from eukaryotic colonizers (e.g., necrophagous insects). Additionally, microbial communities were identified at phylum level using high throughput sequencing during a single study. We hypothesized that carrion microbial community functional profiles would change over the duration of decomposition and that this change would correlate with season, year, and presence of necrophagous insect colonization. Biolog EcoPlates™ were used to measure the variation in epinecrotic microbial community function by the differential use of 29 carbon sources throughout vertebrate carrion decomposition. Pyrosequencing was used to describe the bacterial community composition in one experiment to identify key phyla associated with community functional changes. Overall, microbial functional activity increased throughout decomposition in spring, summer, and winter, while it decreased in autumn. Additionally, microbial functional activity was higher in 2011 when necrophagous arthropod colonizer effects were tested. There were inconsistent trends in the microbial function that was isolated from necrophagous insect colonization between 2010 and 2011. These data are important in understanding the influence of microbial communities on carrion decomposition, an essential ecosystem process. Further, our results contribute to the growing knowledge base of microbial communities associated with ephemeral resource pulses and their influence on decomposition processes.