Ww. Mohn et Gr. Stewart, BACTERIAL METABOLISM OF CHLORINATED DEHYDROABIETIC ACIDS OCCURRING INPULP AND PAPER-MILL EFFLUENTS, Applied and environmental microbiology, 63(8), 1997, pp. 3014-3020
Chlorinated dehydroabietic acids are formed during the chlorine bleach
ing of wood pulp and are very toxic to fish. Thus, destruction of thes
e compounds is an important function of biological treatment Systems f
or pulp and paper mill effluents. In this study, 12 strains of diverse
, aerobic resin acid-degrading bacteria mere screened for the ability
to grow on chlorinated dehydroabietic acids as sole organic substrates
. ALI seven strains of the class Proteobacteria able to use dehydroabi
etic acid were also able to use a mixture of 12- and 14-chlorodehydroa
bietic acid (Cl-DhA). None of the strains used 12,14-dichlorodehydroab
ietic acid, Sphingomonas sp. strain DhA-33 grew best on Cl-DhA and sim
ultaneously removed both Cl-DhA isomers. Ralstonia sp. strain BKME-6 w
as typical of most of the strains tested, growing more slowly on Cl-Dh
A and leaving higher residual concentrations of Cl-DhA than DhA-33 did
. Strains DhA-33 and BKME-6 mineralized (converted to CO2 plus biomass
) 32 and 43%, respectively, of carbon in Cl-DhA consumed. Strain DhA-3
3 produced a metabolite from Cl-DhA, tentatively identified as 3-oxo-1
4-chlorodehydroabietin, and both strains produced dissolved organic ca
rbon which may include unidentified metabolites. Cl-DhA removal mas in
ducible in both DhA-33 and BKME-6, and induced DhA-33 cells also remov
ed 12,14-dichlorodehydroabietic acid, Based on activities of strains D
hA-33 and BKME-6, chlorinated DhAs, and potentially toxic metabolite(s
) of these compounds, are relatively persistent in biological treatmen
t systems and in the environment.