ABE 990
SEMINAR
When: 1:30 PM, Friday, Feb. 11, 2011
Where: 1B77 Engineering
Speaker: Dyan Pratt (Ph.D. student)
Determination of Microbial
Communities beneath Livestock
Burial Sites
Topic:
A ten year old livestock burial site near Pierceland,
Saskatchewan was continuously cored and analyzed for microbial
communities at varying depths below the soil surface by new
and emerging molecular methods. 16S rRNA gene targets and
quantitative PCR was utilized to provide a quantitative analysis
of genomes per gram of soil and cpn-60 targets were used to
amplify
DNA
for
taxonomic
profiling
by
454
pyrosequencing. Quantification results demonstrate a three
orders of magnitude greater difference in genomes at depths
within and up to two meters below the burial trench as
compared to a background core. Topsoil and depths below 6
meters show similar quantities of microbes for both the core
through the burial trench and the background core. A total of
5905 OTUs was found at a variety of abundances in all of the 13
core samples that were analyzed. Taxonomic analysis indicated
that the overall community composition changed considerably
with increasing depth, and that the burial core community was
distinct from the control core at the same depth. In the burial
core, organisms
that are
associated with phosphate
accumulation, nitrogen fixation, and ammonium oxidation were
found in highest abundance near the surface (up to 2.5 m),
while organisms associated with sulfate reduction were
concentrated just below the burial depth (4.5-4.8 m). The
microbial community at the burial site (3.75 m) was dominated
by anaerobic microorganisms.