کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4483812 1316900 2010 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Fungal and bacterial mediated denitrification in wetlands: Influence of sediment redox condition
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Fungal and bacterial mediated denitrification in wetlands: Influence of sediment redox condition
چکیده انگلیسی

Fungal and bacterial denitrification rates were determined under a range of redox conditions in sediment from a Louisiana swamp forest used for wastewater treatment. Sediment was incubated in microcosms at 6 Eh levels (−200, −100, 0, +100, +250 and +400 mV) ranging from strongly reducing to moderately oxidizing conditions. Denitrification was determined using the substrate-induced respiration (SIR) inhibition and acetylene inhibition methods. Cycloheximide (C15H23NO4) was used as the fungal inhibitor and streptomycin (C21H39N7O12) as the bacterial inhibitor. At Eh values of +250 mV and +400 mV, denitrification rates by fungi and bacteria were 34.3–35.1% and 1.46–1.59% of total denitrification, respectively, indicating that fungi were responsible for most of the denitrification under aerobic or weakly reducing conditions. On the other hand, at Eh −200 mV, denitrification rates of fungi and bacteria were 17.6% and 64.9% of total denitrification, respectively, indicating that bacteria were responsible for most of the denitrification under strongly reducing conditions. Results show fungal denitrification was dominant under moderately reducing to weakly oxidizing conditions (Eh > +250 mV), whereas bacterial denitrification was dominant under strongly reducing condition (Eh < −100 mV). At Eh values between −100 to +100 mV, denitrification by fungi and bacteria were 37.9–43.2% and 53.0–51.1% of total denitrification, respectively, indicating that both bacteria and fungi contributed significantly to denitrification under these redox conditions. Because N2O is an important gaseous denitrification product in sediment, fungal denitrification could be of greater ecological significance under aerobic or moderately reducing conditions contributing to greenhouse gas emission and global warming potential (GWP).

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Water Research - Volume 44, Issue 8, April 2010, Pages 2441–2450
نویسندگان
, ,