Appleton, Janet E (1973) Studies of the mycoflora of some lead contaminated soils. Doctoral thesis, Keele University.

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Abstract

An ecological study of the mycoflora of some lead contaminated soils was undertaken. Five soils were sampled bimonthly over a two year period. Two of the soils consisted of old mine 'Tailings', both of which had received an application of topsoil at some time. Two other soils were a result of the processing of the ore for marketing and the remaining soil sampled was part of an agricultural field nearby.
The numbers of fungi found in all the soils sampled were appreciably lower than those in normal soils. This was so even in the agricultural field which did not contain so much lead as the other soils, but contained many more isolates/gram than the other soils. A wide variety of species was isolated from the soils but only a few were major contributors to the mycoflora. All species isolated have been found previously in soils to varying extents. There were some differences between the soils investigated and normal soils, but these were not in the kind of species but their relative numbers. However, the differences were not sufficient to give rise to a distinctive flora associated with lead soils. Two fungi in particular occurred more than in normal soils - Coniothyrium fuckelii and Phoma herbanun. The latter seemed to be an important member of the mycoflora of the spoil heaps.
The soils were also studied for seasonal variation and the effect of depth. It was found that there was no apparent seasonal differences but numbers of both species and isolates were affected adversely by depth. In addition to the ecological studies the effect of lead on the growth of Aspergillus fumigatus Fres. was investigated. On solid media growth could occur at very high concentrations up to 1500 p.p.m. Most of the experiments were conducted using liquid media in which growth was prevented above 170 p.p.m. Germination of A. fumigatus spores can occur over a wide range of lead concentrations, but mycelial growth is much more limited. Tolerance of lead by the mycelium increases until after four days it has no effect on the growth of the mycelium. Lead would seem to be fungistatic rather than fungicidal, since it hinders growth but does not prevent it and once the lead is removed growth continues normally.
In addition to the effect of lead on the growth of A. fumigatus isolates of some species from spoil and non lead-containing areas were compared for their ability to grow on lead-containing media. There was a varied reaction of the isolates which indicated that the fungal flora was composed of two types. One kind of fungus was normally lead tolerant while the other developed a higher lead tolerance in the spoil.

Item Type: Thesis (Doctoral)
Subjects: Q Science > QH Natural history > QH301 Biology
Divisions: Faculty of Natural Sciences > School of Life Sciences
Depositing User: Lisa Bailey
Date Deposited: 01 Mar 2019 14:34
Last Modified: 01 Mar 2019 14:34
URI: http://eprints.keele.ac.uk/id/eprint/5969

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