Screening fungi tolerant to Western red cedar (Thuja plicata Donn) extractives. Part 2. Development of a feeder strip assay

Abstract

Western red cedar (Thuja plicata Donn) is a naturally durable softwood species native to British Columbia in Canada, and Washington, Oregon and California in the USA. Untreated T. plicata products are usually durable because of the presence of extractives with anti-microbial activity. However, there are extractive tolerant fungi that can attack T. plicata. To screen for extractive-tolerant species we developed a T. plicata feeder strip assay. When the feeder strips were placed on malt extract agar, extractives from the wood accumulated in the media and strongly inhibited growth of non-tolerant fungal strains. Extractives remaining in feeder strips following incubation on media were characterized. Of the many compounds leached out, g-and b-thujaplicin, b-thujaplicinol, plicatic acid and thujic acid were quantified. The growth of selected fungal strains was not affected by plicatic acid; however, it was inhibited to different degrees by band g-thujaplicin. Pachnocybe ferruginea was extractivetolerant and may play an important role in the initial stages of degradation of T. plicata products.

Screening fungi tolerant to Western red cedar (Thuja plicata Donn) extractives. Part 1. Mild extraction by ultrasonication and quantification of extractives by reverse-phase HPLC

“…In a subsequent paper on screening extractive-tolerant fungal species (Part 2), this technique was applied (Lim et al 2007). Using RP-HPLC with UV detection, concentrations of 0.6-3.0 mg ml -1 were detect-Brought to you by | University of Arizona Authenticated Download Date | 5/25/15 6:49 PM ed.…”

Synthesis and biological activities of α-pinene-based dithiadiazoles

“…The phenolic-type extractives of wood and bark are known to be bioactive against fungi, termites, and marine borer (Willför et al 2003a(Willför et al ,b, 2005(Willför et al , 2009Venäläinen et al 2006;Lim et al 2007;Mburu et al 2007;Binbuga et al 2008;Borges et al 2008;Gao et al 2008;DonosoFierro et al 2009;Little et al 2010). However, terpenoids present in resin secretion of pinewood are bioactive and also otherwise utile for the production of fine chemicals.…”

Assessment of total phenols and extractives of mahogany wood by near infrared spectroscopy (NIRS)

“…They are responsible for colour and resistance to fungi, insects and marine borers. They may also act as toxins, as well as repellents to insects, and have antioxidant properties (Fengel and Wegener 1984 ;Ven ä l ä inen et al 2006 ;Lim et al 2007 ;Mburu et al 2007 ;Binbuga et al 2008 ;Borges et al 2008 ;Gao et al 2008 ;Donoso -Fierro et al 2009 ;Little et al 2010 ). Chemically, the extractives vary between species, genera, and various anatomical parts of wood may differ in terms of concentration and composition.…”