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ARS Home » Southeast Area » Florence, South Carolina » Coastal Plain Soil, Water and Plant Conservation Research » Research » Publications at this Location » Publication #231569

Title: Characterization of a microbial community capable of nitrification at cold temperature

Author
item Ducey, Thomas
item Vanotti, Matias
item SHRINER, ANTHONY
item SZOGI, ARIEL
item ELLISON, APREL

Submitted to: Bioresource Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/30/2009
Publication Date: 1/7/2010
Citation: Ducey, T.F., Vanotti, M.B., Shriner, A.D., Szogi, A.A., Ellison, A.Q. 2010. Characterization of a microbial community capable of nitrification at cold temperature. Bioresource Technology. 101:491-500.

Interpretive Summary: Liquid manure generated from livestock production is a major contributor to ammonia emissions in rural areas. These emissions may produce eutrophication of coastal waters, lakes, streams, and terrestrial ecosystems, resulting in habitat degradation. The implementation of ammonia removal technology in livestock effluents is difficult due to low efficiency of nitrification in winter months. In this report we have identified a bacterial community capable of oxidizing ammonia to nitrite under cold temperature (5 and 10°C) conditions. We have identified several Nitrosomonas isolates which contribute to this oxidation. In addition we have identified organisms capable of floc and filament formation, denitrification, and cold temperature tolerance (psychrotolerance). We speculate that the psychrotolerant organisms in this bacterial community confer cold resistance to the entire community, resulting in good nitrification performance at cold temperatures.

Technical Abstract: While the oxidation of ammonia is an integral component of advanced aerobic livestock wastewater treatment, the rate of nitrification by ammonia oxidizing bacteria is drastically reduced at colder temperatures. In this study we report an acclimated lagoon nitrifying sludge that is capable of high rates of nitrification at temperatures from 5°C (11.2 mg N/g MLVSS/h) to 20°C (40.4 mg N/g MLVSS/h). The composition of the microbial community present in the nitrifying sludge was investigated by partial 16S rDNA gene sequence-based, non-culturing molecular methods. After DNA extraction and the creation of a plasmid library, 153 partial length 16S rDNA gene clones were sequenced and analyzed phylogenetically. Over 80% of these molecular isolates were affiliated with the Proteobacteria, and grouped with the Beta-(114 clones), Gamma-(7 clones), and Alpha-classes (2 clones) respectively. The remaining molecular isolates were affiliated with the Acidobacteria (1 clone), Actinobacteria (8 clones), Bacteroidetes (16 clones), and Verrucomicrobia (5 clones). The majority of the molecular isolates belonged to the genus Nitrosomonas, while other molecular isolates affiliated with microorganisms previously identified as being capable of filament and floc formation, nitrite reduction, and psychrotolerance.