Quantitative selection of denitrifying bacteria in continuous cultures and requirement for organic carbon. I. Starch.
A mixed population of bacteria from bottom sludge of nitrogen wastewater reservoir was incubated in continuous culture in medium containing 1000 mg nitrate nitrogen/l and starch. Maximal efficiency of denitrification was 5 mg N/l/h. Marked changes in participation of denitrifying bacteria (16-76%) among total number of bacteria was observed, this being dependent on the ratio of starch concentration (CS) to nitrogen concentration (CN) in the medium. The optimal CS/CN ratio ensuring highest participation of denitrifying bacteria was 3.2. The amount of starch required for the denitrification of a defined quantity of nitrogen is negatively correlated (r = -0.98) with the frequency of the occurrence of denitrifying bacteria (XD) and is: CS = (5.53-0.028XD) CN. The denitrifying bacteria in continuous culture were dominated, depending on CS/CN ratio and flow rate of medium, by Alcaligenes faecalis, Paracoccus denitrificans or Pseudomonas mendocina, that is species unable to hydrolyse starch.
Mycielski
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Jaworowska-Deptuch
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Błaszczyk
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D001419:Bacteria / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism; D003470:Culture Media; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D013213:Starch / Q000494:pharmacology*
D003470:Culture Media; D009566:Nitrates; D002244:Carbon; D013213:Starch; D009584:Nitrogen