Abstract

Gut bacteria in macroinvertebrates in streams and rivers contribute to nitrous oxide (N2O) emissions from these systems through partial denitrification. Denitrification is an anaerobic microbial process which converts nitrates (NO3) to dinitrogen (N2), removing excess nitrogen from these ecosystems. Poor stream quality negatively impacts the diversity and abundance of certain macroinvertebrate taxa, such as stoneflies, mayflies and caddisflies. The objective of this project was to quantify the abundance of gut-associated denitrifying bacteria in insects from freshwater bodies that differ in quality (Tinker’s Creek, TC and West Branch of the Mahoning River, WBM) and determine if stream quality impacts both insect taxa, as well as gut-associated denitrifying bacteria. Samples of insects, water, and biofilms from debris were collected from these streams. Stream quality impacted macroinvertebrate taxa, with more sensitive insect taxa present in WB relative to TC. Four insect families, Chironomidae, Elmidae, Hydropsychidae and Cambaridae were common in both streams. The insect family Lestidae was only found in TC and Baetidae, Perlidae and Empididae were only found in WB. Bacterial 16S rDNA, and the denitrification genes nirK and nosZ were detected in all samples. This will be followed by quantitative PCR (qPCR) to determine if stream quality also impacts gut-associated denitrifying bacteria among the insect taxa common to both streams.

Modified Abstract

Gut bacteria in macroinvertebrates in streams and rivers contribute to nitrous oxide (N2O) emissions from these systems through partial denitrification. Denitrification is an anaerobic microbial process which converts nitrates (NO3) to dinitrogen (N2), removing excess nitrogen from these ecosystems. Poor stream quality negatively impacts the diversity and abundance of certain macroinvertebrate taxa, such as stoneflies, mayflies and caddisflies. Stream quality impacted macroinvertebrate taxa, with more sensitive insect taxa present in WB relative to TC. Bacterial 16S rDNA gene, and the denitrification genes nirK and nosZ were detected in all samples. The quantification of bacterial genes in all samples however remains to be investigated.

Research Category

Biology/Ecology

Author Information

Allison BeckwithFollow

Primary Author's Major

Biotechnology

Mentor #1 Information

Dr. Laura Leff

Mentor #2 Information

Dr. Paul Ayayee

Presentation Format

Poster

Start Date

21-3-2017 1:00 PM

Research Area

Biotechnology | Terrestrial and Aquatic Ecology

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Mar 21st, 1:00 PM

Effects of stream quality on insect-gut associated denitrifying bacteria abundance

Gut bacteria in macroinvertebrates in streams and rivers contribute to nitrous oxide (N2O) emissions from these systems through partial denitrification. Denitrification is an anaerobic microbial process which converts nitrates (NO3) to dinitrogen (N2), removing excess nitrogen from these ecosystems. Poor stream quality negatively impacts the diversity and abundance of certain macroinvertebrate taxa, such as stoneflies, mayflies and caddisflies. The objective of this project was to quantify the abundance of gut-associated denitrifying bacteria in insects from freshwater bodies that differ in quality (Tinker’s Creek, TC and West Branch of the Mahoning River, WBM) and determine if stream quality impacts both insect taxa, as well as gut-associated denitrifying bacteria. Samples of insects, water, and biofilms from debris were collected from these streams. Stream quality impacted macroinvertebrate taxa, with more sensitive insect taxa present in WB relative to TC. Four insect families, Chironomidae, Elmidae, Hydropsychidae and Cambaridae were common in both streams. The insect family Lestidae was only found in TC and Baetidae, Perlidae and Empididae were only found in WB. Bacterial 16S rDNA, and the denitrification genes nirK and nosZ were detected in all samples. This will be followed by quantitative PCR (qPCR) to determine if stream quality also impacts gut-associated denitrifying bacteria among the insect taxa common to both streams.