Premium
Nitrification and Denitrification Gene Abundances in Swine Wastewater Anaerobic Lagoons
Author(s) -
Ducey Thomas F.,
Shriner Anthony D.,
Hunt Patrick G.
Publication year - 2011
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2010.0387
Subject(s) - nitrous oxide reductase , denitrification , ammonia monooxygenase , nitrite reductase , nitrification , nitrite , wastewater , environmental chemistry , biology , anaerobic exercise , cycling , abundance (ecology) , nitrogen cycle , denitrifying bacteria , anammox , nitrous oxide , ecology , relative species abundance , nitrate , environmental science , chemistry , environmental engineering , nitrogen , physiology , history , organic chemistry , archaeology
Although anaerobic lagoons are used globally for livestock waste treatment, their detailed microbial cycling of N is only beginning to become understood. Within this cycling, nitrification can be performed by organisms that produce the enzyme ammonia monooxygenase. For denitrification, the reduction of nitrite to nitric oxide can be catalyzed by two forms of nitrite reductases, and N 2 O can be reduced by nitrous oxide reductase encoded by the gene nosZ. The objectives of this investigation were to (i) quantify the abundance of the amoA , nirK , nirS , and nosZ genes; (ii) evaluate the influence of environmental conditions on their abundances; and (iii) evaluate their abundance relative to denitrification enzyme activity (DEA). Samples were analyzed via real‐time quantitative polymerase chain reaction and collected from eight typical, commercial anaerobic, swine wastewater lagoons located in the Carolinas. The four genes assayed in this study were present in all eight lagoons. Their abundances relative to total bacterial populations were 0.04% ( amoA ), 1.33% ( nirS ), 5.29% ( nirK ), and 0.27% ( nosZ ). When compared with lagoon chemical characteristics, amoA and nirK correlated with several measured variables. Neither nirS nor nosZ correlated with any measured environmental variables. Although no gene measured in this study correlated with actual or potential DEA, nosZ copy numbers did correlate with the disparity between actual and potential DEA. Phylogenetic analysis of nosZ did not reveal any correlations to DEA rates. As with other investigations, analyses of these genes provide useful insight while revealing the underlying greater complexity of N cycling within swine waste lagoons.