Studies in the production and effects of volatile fungal metabolites

Marshall, Alison May (1971) Studies in the production and effects of volatile fungal metabolites. PhD thesis, University of Glasgow.

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Abstract

Previous surveys in this Department have been extended by examining 35 species of Fomes and 12 species of Clitocyte. Seventeen Fomes species showed biological activity against at least one of the assay organisms (lettuce, Aspergillus niger and 8 bacteria). There was no particular pattern of activity in this group. Fifteen species showed conspicuous peaks on G.L.O. traces. Of these, only two groups of species, one of 5 and one of 4, produced similar G.L.O. patterns. The conspicuous peaks produced by one of these groups, (F. pomaceus et al.) was subsequently shown to be due to the presence of methyl chloride. No other patterns, were produced by more than one species. There was no consistent correlation between biological activity and the production of conspicuous peaks on G.L.C. traces and ho consistent correlation of pattern production with any existing taxonomic arrangement, Hexatriyne, previously reported from F. annosus was not produced by any species examined hers. The inhibition of lettuce seedling growth by the culture gases of F. scutellatus has been show to be attributable to the production of gaseous hydrogen cyanide. A new adaption of Feigl & Anger's technique was developed for quantitative measurement of HCN in this study. The factor responsible for characteristic inhibition of lettuce root growth by F. noxius has not been identified. None of the compounds, acetaldehyde, ethanol, isobutanol or a mixture of pentanols which gave conspicuous peaks on G.L.C. traces produced comparable inhibition either individually or in mixtures. There are indications that a sulphur-containing compound are awaiting analysis. Nine of the Clitocybe species showed biological activity against at least one of the assay species. A pattern of activity was observed which correlated with the production of hydrogen cyanide. All 4 species, C. geotropa, C. infundibuliformis, C. Candida and C. cyanthiformis, producing HCN inhibited lettuce seedling growth, the first two of these also consistently inhibited growth and stimulated sporulation of A. niger; C. Geotropa inhibited the growth of bacteria. The concentrations of HCN produced by these species were shown to be sufficient to account for the inhibitory effects produced on lettuce; other effects of these species have not been examined further. Nine Clitocybe species produced conspicuous peaks on G.L.C. traces. Of these, only two produced similar patterns. No other pattern was produced by more than one species, although there are indications that several species may be producing similar compounds. Earlier work was extended by examining the factor reported to stimulate production of zygospores in Rhizopus sexualis at low temperatures. This factor could not be identified. Zygospore production was found to be variable over the critical temperature range and differences of one Centigrade degree had a large effect on the numbers of zygospores produced. Because of this, it was suspected that physical factors could contribute to the stimulation effect under certain circumstances. The effect of F. scutellatus and F. noxius gases acting through soil was studied briefly with a view to examining the possible effects of volatile metabolites in nature. The inhibition produced by these species through soil layers of three types was similar to that demonstrated on agar medium.

Item Type: Thesis (PhD)
Qualification Level: Doctoral
Additional Information: Adviser: S A Hutchinson
Keywords: Microbiology
Date of Award: 1971
Depositing User: Enlighten Team
Unique ID: glathesis:1971-73929
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 14 Jun 2019 08:56
Last Modified: 14 Jun 2019 08:56
URI: http://theses.gla.ac.uk/id/eprint/73929

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