The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Phospholipid fatty acid composition and heavy metal tolerance of soil microbial communities along two heavy metal-polluted gradients in coniferous forests

På svenska

Author

Summary, in English

The effects of long-term heavy metal deposition on microbial community structure and the level of bacterial community tolerance were studied along two different gradients in Scandinavian coniferous forest soils. One was near the Harjavalta smelter in Finland, and one was at Ronnskar in Sweden. Phospholipid fatty acid (PLFA) analysis revealed a gradual change in soil microbial communities along both pollution gradients, and most of the individual PLFAs changed similarly to metal pollution at both sites. The relative quantities of the PLFAs br18:0, br17:0, i16:0, and i16:1 increased with increasing heavy metal concentration, while those of 20:4 and 18:2(omega)6, which is a predominant PLFA in many fungi, decreased. The fungal part of the microbial biomass was found to be more sensitive to heavy metals. This resulted in a decreased fungal/bacterial biomass ratio along the pollution gradient towards the smelters. The thymidine incorporation technique was used to study the heavy metal tolerance of the bacteria. The bacterial community at the Harjavalta smelter, exposed mainly to Cu deposition, exhibited an increased tolerance to Cu but not to Cd, Ni, and Zn. At the Ronnskar smelter the deposition consisting of a mixture of metals increased the bacterial community tolerance to all tested metals. Both the PLFA pattern and the bacterial community tolerance were affected at lower soil metal concentrations than were bacterial counts and bacterial activities. At Harjavalta the increased Cu tolerance of the bacteria and the change in the PLFA pattern of the microbial community were found at the same soil Cu concentrations. This indicated that the altered PLFA pattern was at least partly due to an altered, more metal-tolerant bacterial community. At Ronnskar, where the PLFA data varied more, a correlation between bacterial community tolerance and an altered PLFA pattern was found up to 10 to 15 km from the smelter. Farther away changes in the PLFA pattern could not be explained by an increased community tolerance to metals.

Publishing year

1996

Language

English

Pages

420-428

Publication/Series

Applied and Environmental Microbiology

Volume

62

Issue

2

Document type

Journal article

Publisher

American Society for Microbiology

Topic

  • Biological Sciences

Status

Published

Research group

  • Microbial Ecology

ISBN/ISSN/Other

  • ISSN: 0099-2240