Original paper

Alterations in respiration in nitrophenol-grown soil isolates of Nostoc spp.

Amineni, Umamaheswari; Kadiyala, Venkateswarlu


Three nitrophenols (o-nitrophenol (ONP), m-nitrophenol (MNP) and 2,4-dinitrophenol (2,4-DNP)) were assessed for their nontarget effects in altering activities of certain enzymes of glyoxylate, glycolytic and tricarboxylic acid (TCA) cycles on selected strains of Nostoc muscorum and N. linckia. There was a significant decrease in the activity of glucose-6-phosphate dehydrogenase, which is involved in the pentose pathway. The activities of glycolytic pathway enzymes such as hexokinase and aldolase were significantly enhanced during nitrophenol stress in the selected cultures. Both isocitrate dehydrogenase and malate dehydrogenase involved in TCA cycle were significantly more activated in the cultures grown with nitrophenols, indicating that more of isocitrate would be either converted to α-ketoglutarate or directed towards the glyoxylate cycle.


cyanobacterianostoc spprespirationnitrophenolstoxicity