title: Acute toxic effects of three pesticides on Pseudomonas putida monitored by microcalorimeter.
abstract: A series of calorimetric experiments were performed to investigate the toxic effects of beta-cypermethrin (BCP), bensulfuron-methyl (BSM) and prometryne (PM) on Pseudomonas putida (P. putida). The metabolic action of P. putida on the three pesticides was studied by obtaining power-time curves. The growth of P. putida was inhibited completely in each case when the concentrations of pesticides were up to 80 micro g mL(- 1). The relationships between the inhibitory ratio (k) and doses of contaminants were approximately linear for the three pesticides. The total heat dissipated per milliliter (Q(total)) for the pesticides decreased during the course of the experiment. The OD(600) of P. putida growth in the absence and presence of pesticides was also obtained. The power-time curves of P. putida growth coincided with its turbidity curves. This elucidates that microcalorimetric method agrees well with the routine microbiological method. Among these three pesticides, BSM was found to be the most toxic with an IC(50) of 19.24 micro g mL(- 1) against P. putida. PM exhibited moderate virulence with an IC(50) of 27.86 micro g mL(- 1) and BCP had the lowest toxicity with an IC(50) of 39.64 micro g mL(- 1).
authors.affiliation: Key Laboratory of Biogeology and Environmental Geology of Chinese Ministry of Education & School of Environmental Studies & Sino-Hungarian Joint Laboratory of Environmental Science and Health, China University of Geosciences, Wuhan, P. R. China.
authors.forename: Hui-Lun
authors.initials: HL
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Yao
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Emilia
authors.initials: E
authors.lastname: Bramanti
authors.forename: Thomas
authors.initials: T
authors.lastname: Maskow
authors.forename: Gyula
authors.initials: G
authors.lastname: Zaray
mesh_terms: D002151:Calorimetry; D010575:Pesticides / Q000633:toxicity*; D011400:Prometryne / Q000633:toxicity; D016958:Pseudomonas putida / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D011722:Pyrethrins / Q000633:toxicity; D013453:Sulfonylurea Compounds / Q000633:toxicity; D013997:Time Factors; D023382:Toxicity Tests, Acute
chemical_list: D010575:Pesticides; D011722:Pyrethrins; D013453:Sulfonylurea Compounds; D011400:Prometryne; C017160:cypermethrin; C071475:methyl bensulfuron