W730 Nitrous Oxide-Producing Fungi in Agricultural Soil

Date: Sunday, January 15, 2012
Time: 9:20 AM
Room: Pacific Salon 2
Wei Shi , North Carolina State University, Raleigh, NC
It is generally accepted that bacteria are the sole microbes contributing to N2O production via denitrification, an anaerobic respiration leading to stepwise reductions of NO3- to NO2-, NO, N2O, and N2. However, recent studies prove that our understanding on microbes capable of denitrification and thus N2O production is far less complete than previously thought. Fungi, once considered inconsequential in soil N2O production, have now been demonstrated to possess denitrification activity. The objective of this study was to examine if N2O-producing fungi were prevalent and thus contributed significantly to N2O production in agricultural soil. A series of soil microcosm experiments were conducted to determine N2O production from diverse agricultural soils. These direct soil measurements revealed that N2O production could be greatly reduced after soils were amended with antifungal antibiotics. Furthermore, a number of fungal isolates from agricultural soils were found to be able to produce N2O at oxygen limited conditions, though production rates varied significantly. To better characterize the distribution and abundance of N2O-producing fungal community in agricultural soil, however, a PCR-based tool needs to be developed.