Journal ArticleDOI
Toxicity of heavy metals to microorganisms and microbial processes in agricultural soils: a review.
Reads0
Chats0
TLDR
In this article, a hypothesis is formulated to explain how microorganisms may become affected by gradually increasing soil metal concentrations and this is discussed in relation to defining safe or critical soil metal loadings for soil protection.Abstract:
An increasing body of evidence suggests that microorganisms are far more sensitive to heavy metal stress than soil animals or plants growing on the same soils. Not surprisingly, most studies of heavy metal toxicity to soil microorganisms have concentrated on effects where loss of microbial function can be observed and yet such studies may mask underlying effects on biodiversity within microbial populations and communities. The types of evidence which are available for determining critical metal concentrations or loadings for microbial processes and populations in agricultural soil are assessed, particularly in relation to the agricultural use of sewage sludge. Much of the confusion in deriving critical toxic concentrations of heavy metals in soils arises from comparison of experimental results based on short-term laboratory ecotoxicological studies with results from monitoring of long-term exposures of microbial populations to heavy metals in field experiments. The laboratory studies in effect measure responses to immediate, acute toxicity (disturbance) whereas the monitoring of field experiments measures responses to long-term chronic toxicity (stress) which accumulates gradually. Laboratory ecotoxicological studies are the most easily conducted and by far the most numerous, but are difficult to extrapolate meaningfully to toxic effects likely to occur in the field. Using evidence primarily derived from long-term field experiments, a hypothesis is formulated to explain how microorganisms may become affected by gradually increasing soil metal concentrations and this is discussed in relation to defining “safe” or “critical” soil metal loadings for soil protection.read more
Citations
More filters
Bioremediation: Developments, Current Practices and Perspectives
TL;DR: This paper represents an exhaustive evaluation with respect to developments, current practices and perspectives of a variety of approaches of bioremediation.
Journal ArticleDOI
Effects of past sewage sludge additions on heavy metal availability in light textured soils: implications for crop yields and metal uptakes.
TL;DR: The results demonstrate the importance of measuring extractable as well as total heavy metal concentrations in topsoils when assessing likely effects on plant yields and metal uptakes, and setting soil quality criteria.
Journal ArticleDOI
Production of Volatile Metabolites by Grape-Associated Microorganisms
TL;DR: Well-known and typical flavor components of red wine were detected as being produced by microbes, for example, 2-methylbutanoic acid, 3-methyl-1-butanol, and ethyl octanoate.
Journal ArticleDOI
Biodegradation of rhamnolipid, EDTA and citric acid in cadmium and zinc contaminated soils
TL;DR: In this paper, the authors investigated the rate of rhamnolipid degradation in soils of varying physicochemical properties and contaminated with varying concentrations of Cd and zinc (Zn).
Journal ArticleDOI
Soil microbial community as bioindicator of the recovery of soil functioning derived from metal phytoextraction with sorghum
TL;DR: Most importantly, although the phytoextracted soil recovered its function, it was still more phytotoxic than the control non-polluted soil.
References
More filters
Journal ArticleDOI
An extraction method for measuring soil microbial biomass c
TL;DR: In this paper, the effects of fumigation on organic C extractable by 0.5 m K2SO4 were examined in a contrasting range of soils and it was shown that both ATP and organic C rendered decomposable by CHCl3 came from the soil microbial biomass.
Journal ArticleDOI
Phylogenetic identification and in situ detection of individual microbial cells without cultivation.
TL;DR: Phylogenetic analysis of the retrieved rRNA sequence of an uncultured microorganism reveals its closest culturable relatives and may, together with information on the physicochemical conditions of its natural habitat, facilitate more directed cultivation attempts.
Journal ArticleDOI
Diversity in tropical rain forests and coral reefs.
TL;DR: The commonly observed high diversity of trees in tropical rain forests and corals on tropical reefs is a nonequilibrium state which, if not disturbed further, will progress toward a low-diversity equilibrium community as mentioned in this paper.
Book
Plant Strategies and Vegetation Processes
TL;DR: In this paper, the authors present plant strategies in the established phase and the regenerative phase in the emerging phase, respectively, and discuss the relationship between the two phases: primary strategies and secondary strategies.
Journal ArticleDOI
Evidence for the existence of three primary strategies in plants and its relevance to ecological and evolutionary theory
TL;DR: A triangular model based upon the three strategies of evolution in plants may be reconciled with the theory of r- and K-selection, provides an insight into the processes of vegetation succession and dominance, and appears to be capable of extension to fungi and to animals.