title: Influence of methylheptenone and related phytoplankton norcarotenoids on heterotrophic aquatic bacteria.
abstract: Certain norcarotenoids, which have recently been found as excretion products of freshwater cyanobacteria and algae, are potent inhibitors of different metabolic functions in heterotrophic bacteria. 6-Methylhept-5-en-2-one showed the strongest effects and acted as a noncompetitive inhibitor of both glucose uptake and respiration by aquatic isolates of Chromobacterium lividum and Arthrobacter sp. Inhibition of the heterotrophic potential of glucose uptake by 6-methylhept-5-en-2-one was characterized by considerably lower inhibitor constants for bacterial cultures (Ki = 0.4 and 1.6 microM) than for a river water sample (Ki = 186.0 microM).
mesh_terms: D001419:Bacteria / Q000187:drug effects* / Q000378:metabolism; D002338:Carotenoids / Q000494:pharmacology*; D005618:Fresh Water; D005947:Glucose / Q000378:metabolism; D007659:Ketones / Q000494:pharmacology*; D010101:Oxygen Consumption / Q000187:drug effects; D010839:Phytoplankton / Q000378:metabolism; D013045:Species Specificity; D014871:Water Microbiology
chemical_list: D007659:Ketones; D002338:Carotenoids; C029750:methylheptenone; D005947:Glucose