title: Microcalorimetric investigation of the toxic action of ammonium ferric(III) sulfate on the metabolic activity of pure microbes.
abstract: A series of calorimetric experiments were performed to investigate toxic action of ammonium ferric sulfate (AFS) on Bacillus subtilis, Pseudomonas putida and Candida humicola. The power-time curves of micro-organism metabolism were obtained, and the action of them by addition of AFS was studied. C. humicola, B. subtilis and P. putida were inhibited completely when the concentrations were up to 320.0, 160.0 and 160.0μgmL(-1), respectively. The relationships between growth rate constant (k) and doses of AFS were approximately linear for three microbes, P. putida for 10.0-160.0μgmL(-1) (R=-0.9746), B. subtilis for 0-160.0μgmL(-1) (R=-0.9868) and C. humicola for 10.0-320.0μgmL(-1) (R=-0.9955). The total heat dissipated per milliliter (Q(T)) for three microbes remained balance approximately during the lower doses, P. putida and B. subtilis less than the dose of 20.0μgmL(-1), 0.56±0.01 and 0.26±0.01JmL(-1), respectively, C. humicola less than the dose of 40.0μgmL(-1), 0.58±0.03JmL(-1). The biomass and OD(600) of three micro-organisms growth in the absence of AFS also were obtained. The power-time curve of C. humicola growth coincided with its turbidity curve. It elucidates that microcalorimetric method agreed with the routine microbiology method.
authors.affiliation: School of Environmental Studies & Key Laboratory of Biogeology and Environmental Geology of Chinese Ministry of Education & Sino-Hungarian Joint Laboratory of Environmental Science and Health, China University of Geosciences, 430074 Wuhan, Hubei, PR China.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Yao
authors.forename: Lin
authors.initials: L
authors.lastname: Tian
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhou
authors.forename: Huilun
authors.initials: H
authors.lastname: Chen
authors.forename: Haiyan
authors.initials: H
authors.lastname: Chen
authors.forename: Nan
authors.initials: N
authors.lastname: Gai
authors.forename: Yanjiao
authors.initials: Y
authors.lastname: Chen
authors.forename: Rensheng
authors.initials: R
authors.lastname: Zhuang
authors.forename: Gyula
authors.initials: G
authors.lastname: Zaray
authors.forename: Thomas
authors.initials: T
authors.lastname: Maskow
authors.forename: Emilia
authors.initials: E
authors.lastname: Bramanti