METABOLIC AND GENETIC DIVERSITY OF PHENOL-UTILIZING BACTERIA AS AN ENHANCER OF NATURAL BIODEGRADATION IN POLLUTED WATERS
E. HEINARU
E. TALPSEP
A. LINNAS
A. HEINARU
Institute of Molecular and Cell Biology
Tartu University
Tartu, Estonia
U. STOTTMEISTER
Centre for Environmental Research (UFZ) Leipzig-Halle LTD
Department of Remediation Research
Leipzig, Germany
| The metabolic and genetic diversity of phenol-utilizing
119 bacterial strains isolated from the rivers polluted by ash dump leachate in Kohtla-Järve,
Estonia, has been studied. Of eighteen different bacterial species identified, 82 % belong to the
genus P s e p u d o m o n a s. Comparison of genetic (phenol monooxygenase /PMO/ and catechol
2,3-dioxygenase /C23O/ gene probes) and biochemical (PMO, C23O, catechol 1,2-dioxygenase and
protocatechuate 3,4-dioxygenase activities) data with species of isolated bacteria shows that
in different polluted regions of the rivers different P s e u d o m o n a s f l u o r e s c e n s
biotypes and P s. m e n d o c i n a are predominant and they harbor characteristic
genetic traits. The incidence of plasmid-bearing bacteria is much higher in phenol- polluted waters (up to 81 % of the strains) than in nonpolluted river waters (38 %). We found three main types of induction of aromatic ring-fission pathways among the isolated phenol-growing bacteria which also grow on p-cresol. Some new bacterial isolates, such as P s. f l u o r e s c e n s strains MT4/4 and I16 revealed even higher biodegradation capabilities of volatile phenols in leachate than laboratory-selected phenol-growing bacteria. |