title: Microcalorimetric investigation of the toxic action of pyrene on the growth of PAH-degrading bacteria Acinetobacter junii.
abstract: A multi-channel thermal activity microcalorimeter was used to determine the pyrene-induced toxic effect on two polycyclic aromatic hydrocarbon (PAH)-degrading bacteria Acinetobacter junii (A. junii) and Bacillus subtilis (B. subtilis). Power-time curves were analyzed and calorimetric parameters including growth rate constant (k), half inhibitory concentration (IC50) and total thermal effect (QT) were obtained. A. junii and B. subtilis were completely inhibited when the concentration of pyrene reached 400 and 160 microg mL(-1), respectively. The relationships between the calorimetric parameters and concentration of pyrene were studied. The growth rate of A. junii decreased with the increase in pyrene concentration at 50-200 microg mL(-1). The growth of biomass for A. junii at various concentrations of pyrene was determined. The count of A. junii after 8 day's incubation reached maximum irrespective of the initial pyrene concentrations ranging from 50 to 200 microg mL(-1) and the smallest stimulative action of pyrene was at 200 microg mL(-1). The variations of biomass during the growth of A. junii were consistent with the microcalorimetric data, indicating that microcalorimetry can be an effective technique to investigate the effect of pyrene on microorganisms.
authors.affiliation: Key Laboratory of Biogeology and Environmental Geology of Chinese Ministry of Education, School of Environmental Studies and Sino-Hungarian Joint Laboratory of Environmental Science and Health, China University of Geosciences, Wuhan, P. R. China.
authors.forename: Yanjiao
authors.initials: Y
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Yao
authors.forename: Ke
authors.initials: K
authors.lastname: Chen
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhou
authors.forename: Huilun
authors.initials: H
authors.lastname: Chen
authors.forename: Nan
authors.initials: N
authors.lastname: Gai
authors.forename: Brunello
authors.initials: B
authors.lastname: Ceccanti
authors.forename: Polonca
authors.initials: P
authors.lastname: Trebse
authors.forename: Gyula
authors.initials: G
authors.lastname: Zaray
authors.forename: Martin M F
authors.initials: MM
authors.lastname: Choi
authors.forename: Ming Hong
authors.initials: MH
authors.lastname: Wong
mesh_terms: D000150:Acinetobacter / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D001412:Bacillus subtilis / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D002151:Calorimetry / Q000379:methods*; D011083:Polycyclic Compounds / Q000378:metabolism*; D011721:Pyrenes / Q000633:toxicity*
chemical_list: D011083:Polycyclic Compounds; D011721:Pyrenes; C030984:pyrene