Development of a Basic Biosensor System for Wood Degradation using Volatile Organic Compounds

Abstract

Wood inspection and durability testing of wood against microorganisms, as fungi, play an important role in forestry and wood-related material industries. An efficient testing method is required in order to facilitate inspections and to provide the accurate and precise assessment process. Monitoring volatile organic compounds (VOCs) released from wood substrates and from fungal metabolisms are marker compounds of the wood condition, i.e., indicating the type and stage of fungal infection. Insect antennae, which are recognised for their high sensitivity and selectivity in odour perception, are an alternative method for wood testing. On the basis of intact insect antenna biosensor it is possible to monitor wood released VOCs with high selectivity. This technique can be a complement to the traditional wood testing methods, providing a high throughput and non-destructive method.This work was begun with the investigation of VOCs released from four different types of samples with gas chromatography-mass spectrometry. Firstly, VOCs from beech wood (Fagus sylvatica) infected with three wood rotting fungi; Trametes versicolor, Poria placenta, and Gloeophyllum trabeum were analysed. These fungi are commonly used in the durability testing of wood against microorganisms. The VOCs released from the fungal-infected beech showed species specific volatile patterns. The volatiles were grouped to five-and to eight-carbon (C5-C8) containing compounds and terpenoids. 1-Octen-3-ol, 3-octanone, and 3-octanol (C8-compounds) were commonly present in all samples, while terpenoids were species specific. α-and β-Barbatene were characteristic of T. versicolor-infected beech, protuillud-6-ene was characteristic of G. trabeum-infected beech, and daucene was characteristic of P. placenta-infected beech. Secondly, VOCs released from the minimally insect-colonised fruiting body (<10%) and fully insect-colonised fruiting body (~100%) of Trametes gibbosa were identified. The minimally insect-colonised fruiting body released 1octen-3-ol, the typical fungal odour, at almost 20 times higher than in fully insectcolonised fruiting body. Thirdly, VOCs released during the fruiting body development of the ink-cap Coprinopsis cinerea, from the stage of mycelium to fruiting body autolysis, were studied. VOCs patterns of C. cinerea were specifically altered by the developmental stages.

The Economic Value of Forest Bathing: An Example Case of the Italian Alps

“…However, large logs at different decomposition levels are important to stimulate three senses: visual, tactile, and olfactory. Visually, large logs are esthetically pleasing to many visitors, as highlighted by many studies [68,69], while heavily decomposed logs stimulate the sense of smell [70], and they can be an important tactile stimulus during the forest bathing experience. Regarding the presence of water elements, Ulrich et al [71] demonstrated that natural settings (e.g., water streams and trees) influence physiological stress reduction responses.…”

Trapping the exotic weevilCnestus mutilatuswith Isopropanol

“…In addition to attracting various insects into traps (38)(39)(40)(41)(42)(43)(44)(45)(46), it is known to volatize from insects (47), stimulate oviposition (48), and evoke antennal electrophysiological responses (46,47). Isopropanol also volatizes from some plants (38,41,(48)(49)(50)(51)(52)(53)(54) and fungi (55,56). Stress-related processes such as fermentation (57,58) and amino acid metabolism (59-61) can result in the production of isopropanol.…”