Phycomyces blakesleeanus BURGEFF and several wood-decay fungi in a bioassay for growth factor resources in fresh and microbially precolonized timber
✍ Scribed by G. Grams
- Book ID
- 102393967
- Publisher
- John Wiley and Sons
- Year
- 1990
- Tongue
- English
- Weight
- 494 KB
- Volume
- 30
- Category
- Article
- ISSN
- 0233-111X
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✦ Synopsis
Abstract
The presence of the essential growth factor thiamine in timber was ascertained with the determination of the mycelial growth figures of several indicator fungi on the respective timber substrates. The behaviour of the absolutely thiamine‐dependent phycomycete, Phycomyces blakesleeanus BURGEFF (Pb), as well as of 6 strains of basidiomycetous wood‐decay fungi (WBF) that did or did not depend on exogenous vitamin supply proved in accordance that (i) both sapwood and heartwood material of 14 native timber species examined were able to furhish fungi with any degree of vitamin dependence with the essential growth factor(s); (ii) both fresh timber and timber pre‐colonized by bacteria, ascomycetous discolouration fungi, and WBF contained thiamine resources above the saturation level of 50 μg per kg; (iii) neither a thiamine supply of 2 to 20 mg per kg total weight nor the residues of microbial pre‐colonizers added to the vitamin pool of timber in that the growth of the test fungi could be further stimulated; (iv) the depressive growth of WBF on vitamin‐free liquid media was not observed on vitamin‐free solid media such as fertilized builder's sand. A vitamin supply did not improve the vigour of WBF of any degree of vitamin dependence, but it was a prerequisite for the growth of Pb on these substrates.
It is concluded that vitamins in timber have, on their permanent excessive presence, no ecological significance. They do not add to host wood specificity, to the election of the fungus' host range, to the specialization for gymnosperm wood, to the preference for sapwood or heartwood within the stem, to the establishment of pathogenesis on standing timber, and to the preference for fresh or pre‐colonized wood material.