Population Dynamics of Two Toluene Degrading Bacterial Species in a Contaminated Stream

• Published in: Microbial ecology Vol. 41; no. 2; pp. 124 - 131
• Main Authors: S. T.-L. Tay, F. H. Hemond, L. R. Krumholz, Cavanaugh, C. M., M. F. Polz
• Format: Journal Article
• Language: English
• Published: New York, NY Springer-Verlag New York Inc 01-02-2001; Springer; Springer Nature B.V
• Subjects: Animal, plant and microbial ecology; Bacteria; Biodegradation; Biodegradation of pollutants; Biofilms; Biological and medical sciences; Biotechnology; Environment and pollution; Freshwater; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Microbial ecology; Microbiology; Mycobacterium; Nucleic acids; Polymerase chain reaction; Population dynamics; Product category rules; Stream pollution; Streams; Summer; Toluene; Various environments (extraatmospheric space, air, water); Xanthobacter; Xanthobacter autotrophicus; USA, Massachusetts; Degradation; Mycobacterium; Mycobacteriales; Toluene; Mycobacteriaceae; Biofilm; Bacteria; Actinomycetes; Population dynamics; Water pollution
• ISSN: 0095-3628; 1432-184X
• DOI: 10.1007/s002480000089

Toluene uptake by a benthic biofilm community was previously shown to vary seasonally from 0.03 m hr-1in winter to 0.2 m hr-1in summer in a solvent-contaminated stream of the Aberjona watershed. We used quantitative PCR to estimate the population dynamics of previously isolated species of toluene-degrading Xanthobacter autotrophicus and Mycobacterium sp. in both toluene-contaminated and uncontaminated reaches of the stream, and to estimate their relative roles in overall biodegradation rate. Quantification using specific 16S rDNA primers for X. autotrophicus and Mycobacterium sp. showed that populations of both species were much larger in the toluene-contaminated than the toluene-free reach, in agreement with earlier culture-based investigations. A relatively brief bloom of X. autotrophicus occurred in the contaminated reach in the summer, while Mycobacterium sp. populations occurred at elevated densities for more than 5 months. Calculations showed that Mycobacterium, previously thought to be less important than Xanthobacter in annual toluene degradation based on single time-point CFU estimates, appears actually more important because of this longer persistence.