Influence of heavy metals on the electrical conductivity of melanized pseudosclerotial plates in spalted wood

Kalač, Tine (author), Humar, Miha (mentor)

Zone lines in wood are formed on the border of two mutually antagonistic fungi. These lines, also known as pseudosclerotial plates, owe their colour to the presence of melanin. Recently, melanin has been studied for its semiconductive properties. Melanin is also known for its ability to absorb various heavy metals. Within our study, we isolated several mutually antagonistic strains of Kretzschmaria deusta, examined the possible toxic effect of the heavy metals on the fungi by measuring growth rates, described a novel method for producing wood with zone lines with the isolated fungi, and assessed the influence of selected heavy metals on the electrical conductivity of melanin in pseudosclerotial plates. We successfully isolated five strains of K. deusta from a naturally infected log. Most of the heavy metals had a negative effect on the fungi, except iron(III) oxide, which was used in producing the final samples. The method for producing zone lines was extremely successful. We assessed that this method could be a good starting point in the development of an industrial process of spalted wood production. Due to the COVID-19 epidemic, the electrical conductivity measurements could not be performed.

• Language: English
• Keywords: spalting, pseudosclerotial plates, Kretzschmaria deusta, melanin/heavy metals, electrical conductivity, mass loss
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [T. Kalač]
• Year: 2020
• PID: 20.500.12556/RUL-121314
• UDC: 630*84
• COBISS.SI-ID: 30714627
• Publication date in RUL: 04.10.2020

Secondary language

• Language: Slovenian
• Title: Vpliv težkih kovin na električno prevodnost melaniziranih pseudosklerotskih conskih linij v piravem lesu

Abstract

Na meji dveh medsebojno antagonističnih kolonij gliv se tvorijo conske linije, ki so vidne kot črne črte v notranjosti lesa. Strokovno se imenujejo pseudosklerotske plošče ali conske linije in vsebujejo melanin, ki jim daje črno obarvanje. V zadnjih desetletjih je melanin vse pogosteje raziskovan zaradi njegovih polprevodniških lastnosti. Melanin je znan po svoji zmožnosti absorbcije težkih kovin. V okviru naše raziskave smo iz narave izolirali več sevov glive Kretzschmaria deusta, ocenili učinek težkih kovin na to glivo z merjenjem hitrosti rasti, opisali novo metodo za proizvajanje vzorcev s conskimi linijami, ter kvantificirali vpliv prisotnosti težkih kovin na električno prevodnost pseudosklerotskih plošč v lesu. Uspešno smo izolirali pet sevov K. deusta iz naravno okuženega debla. Večina težkih kovin je imela negativen vpliv na rast gliv, razen železov(III) oksid, ki smo ga uporabili pri pridobivanju vzorcev s pseudosklerotskimi ploščami. Metoda za pridobivanje vzorcev je bila dosledno uspešna in ocenili smo, da bi lahko predstavljala dobro izhodišče za razvoj industrijskega postopka za pridelavo lesa s conskimi linijami. Zaradi epidemije COVID-19 meritve električne prevodnosti niso bile izvedene.

• Keywords: glivno obarvanje, pseudosklerotske ploščice, Kretzschmaria deusta, melamnin, težke kovine, električna prevodnost, izguba mase