Environmental factors affecting the occurrence of mycobacteria in brook sediments

• Published in: Journal of applied microbiology 1999-04, Vol.86 (4), p.673-681
• Main Authors: Iivanainen, E., Martikainen, P. J., Väauml, nänen, P., Katila, M. ‐L.
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Biological and medical sciences; Climate; Colony Count, Microbial; Fresh Water - microbiology; Fundamental and applied biological sciences. Psychology; Geologic Sediments - chemistry; Geologic Sediments - microbiology; Hydrogen-Ion Concentration; Microbial ecology; Mycobacterium - growth & development; Mycobacterium - isolation & purification; Oxygen Consumption; Soil Microbiology; Various environments (extraatmospheric space, air, water)
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1046/j.1365-2672.1999.00711.x

The occurrence of mycobacteria was studied in aerobic brook sediments from 39 drainage areas in Finland. The culturable counts of mycobacteria were related to climatic conditions, characteristics of the drainage area, chemical characteristics of the sediment and water, culturable counts of other heterotrophic bacteria, and microbial respiration rate in the sediment. The counts of mycobacteria varied from 1·1 × 102 to 1·5 × 104 cfu g−1 dry weight of sediment. They correlated positively with the proportion of the drainage area consisting of peatland, total content of C, content of Pb, microbial respiration rate in the sediment, and chemical oxygen demand of the water. The correlations of the mycobacterial counts with pH of sediment and alkalinity of water were negative. The results of the present sediment study and of the forest soil study published earlier strongly suggest that an increase in acidity increases the counts of mycobacteria and decreases the counts and activity of other heterotrophic bacteria. Mycobacterial counts were more than 100 times higher (per dry weight) in forest soils with pH 3·5–4·3 than in sediments with pH 4·5–6·3.