title: Total RNA concentration as an index of microbial activity and oxygen supply in an oxidation ditch.
abstract: Total RNA and chromosomal DNA concentrations at a municipal wastewater treatment plant with an oxidation ditch (OD) were monitored for 1.5 years using commercial extraction kits for DNA and RNA. No parameters correlated with the chromosomal DNA concentration. The total RNA concentration exhibited better correlation than the solids retention time and the mixed liquor suspended solids with the removal rate of total organic carbon, and can be regarded as an index of microbial activity. The total RNA concentration varied with a cycle of one year and increased at lower water temperatures in this OD. When diffusion theory was taken into account, it was found that the oxygen dissolution rate increased at lower temperature, and a small change in the oxygen dissolution rate caused a large variation in microbial activity and also affected nitrification and denitrification. The information was insufficient to clarify the various reaction relationships, but total RNA concentration will likely be useful as an index of microbial activity in actual wastewater treatment reactors.
authors.affiliation: Department of Management Science and Engineering, Faculty of System Science and Technology, Akita Prefectural University, 84-4 Ebinokuchi, Tsuchiya, Yurihonjo, Akita 015-0055, Japan. kanazawa@akita-pu.ac.jp
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Kanazawa
authors.forename: Yoshikuni
authors.initials: Y
authors.lastname: Urushigawa
authors.forename: Yumio
authors.initials: Y
authors.lastname: Yato
mesh_terms: D001420:Bacteria, Aerobic / Q000235:genetics* / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000379:methods; D002470:Cell Survival / Q000502:physiology; D015169:Colony Count, Microbial / Q000379:methods*; D004269:DNA, Bacterial / Q000032:analysis; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology*; D012329:RNA, Bacterial / Q000032:analysis*; D012722:Sewage / Q000382:microbiology*; D013223:Statistics as Topic
chemical_list: D004269:DNA, Bacterial; D012329:RNA, Bacterial; D012722:Sewage; D010100:Oxygen