Can Penicillium adametzii decrease the damping-off in pine?

Mixture of the Penicillium adametzii metabolites present in the chloroform extract usually did not inhibit the growth of damping−off fungi, including C. destructans, F. oxysporum. F. sambucinum, F. solani and R. solani, in vitro. Extract from the P. adametzii liquid culture: (i) protected the inoculated pine seedlings from the damping−off only temporarily, (ii) decreased the health of the non−inoculated seedlings, (iii) caused the temporary increases of the fungal population in soil, (iv) changed structure of the soil fungi communities, and (v) caused the continuous increase of Trichoderma, mostly T. aureoviride population. The increase of pine seedlings damping−off was connected with the increase of T. aureoviride population in soil. Natural isolates of P. adametzii cannot be considered as the effective biological factor in the biological control of damping−off

Determination of fungal biomass in soil using ergosterol content analysis

The presence of microorganisms in the substrate is detected with increasing frequency using chemical methods. During the first 9 weeks ergosterol concentration in sterile or not sterile soil inoculated with one of the damping−off fungi reached 966 μg/g, while number of colony forming units (cfu) went up to 247×103 cfu/g. Ergosterol concentration was correlated with the size of the soil fungal community estimated in terms of the number of colony forming units in soil. Pearson's correlation coefficient was 0.700−0.946 for sterile and not sterile soil. Higher content of ergosterol was observed for F. sambucinum var. sambucinum, H. haematococca and T. cucumeris while higher average content of cfu was observed for H. haematococca and T. cucumeris

Sterol content in bark after high-temperature drying of wood in convection driers

Bark is a waste material in the furniture industry. It is mainly used for mulching in gardens. To fulfil its task in that field, bark must be microbiologically clean. Ergosterol (ERG) is the main sterol of the fungal cell wall. The research aimed to assess the usefulness of ergosterol concentration analysis for its use in the wood industry in order to quickly assess the level of microscopic contamination of the bark after the drying process. We tested the bark of oak, beech, hornbeam, spruce and pine in terms of ERG concentration and endogenous sterols content. The highest concentration of ERG was obtained for bark of coniferous species (1483.0 and 227.6 mg/kg for spruce and pine respectively), while much lower was found for deciduous (27.4−127.7 mg/kg). No sterols were found in the bark of deciduous trees after the drying process, with the exception of campesterol which was detected only in bark of beech and hornbeam. However, they were found in samples of conifer bark at the level of 1.6−1.78 mg/kg. The bark of deciduous trees is safer in terms of microbiology, and thus can be used in various industries as a secondary raw material

Determination of profiles of volatile metabolites produced by Trametes versicolor isolates antagonistic towards Armillaria spp.

Armillaria root disease is one of the most important diseases causing losses in forestry, horticulture, pomiculture and agriculture. Fungi from Armillaria spp. infest roots and stem base in trees and shrubs, causing white wood rot. In Poland the most common species include Armillaria ostoyae (Romagn.) Herink, found both in coniferous and deciduous stands, and A. gallica Marxm. et Romagn. found in deciduous stands. Identification of antagonistic interactions between microorganisms in the soil medium enables to use their activity to protect plants against pathogens. Analyses were conducted on two Trametes versicolor isolates TR31 and TR55, collected from oak stumps, and 5 fungal species from the genus Armillaria: A. borealis Marxm. et Korhonen, A. cepistipes Velen., A. gallica, A. mellea (Vahl) P. Kumm. and A. ostoyae. Profiles of volatile compounds produced by T. versicolor isolates TR31 and TR55 determined in this study varied in their effect on growth of pathogens Armillaria borealis, A. cepistipes, A. gallica, A. mellea and A. ostoyae. TR31 more effectively than isolate TR55 inhibited growth of fungi from the genus Armillaria. Profiles of volatile compounds biosynthesised in the examined fungal cultures were assessed by headspace microextraction in a gas chromatograph coupled with a mass spectrometer. We detected 179 compounds in the analysed fungal cultures. They belonged to the following groups of chemical compounds: amines, alcohols, terpenes, aldehydes, ketones, hydrocarbons, heterocyclic compounds, esters and aromatic compounds (tab. 2). The most numerous group among the isolated volatile compounds comprised hydrocarbons, alcohols and esters at 32.4%, 16.2% and 14.5%, respectively. The highest concentrations reported in RU (i.e. the peak area of a given substances in relation to the peak area of the internal standard, i.e. tridecane) were recorded for aldehydes, alcohols and hydrocarbons. Among all the identified volatile compounds the highest concentration was observed for 2−methylbutanal. However, it was characteristic only of isolate TR31, which exhibited a greater capacity to inhibit growth of Armillaria spp. in comparison to isolate TR55 (fig.)