Characterization of chikusaku-eki and mokusaku-eki and its inhibitory effect on sapstaining fungal growth in laboratory scale

Abstract

Chikusaku-eki and Mokusaku-eki are natural resources and acidic liquid by-products of bamboo and broad leaved trees charcoal burner. These products contain more than 200 ingredients, including phenols, poly phenols and acetic acids. These by-products were tested for their fungicidal activity against sapstaining fungi. There are no studies about the antifungal activity of Chikusaku-eki and Mokusaku-eki against wood staining fungi in the literature. According to the recent findings, this is the first report about the antifungal activity of Chikusaku-eki and Mokusaku-eki against wood staining fungi. These extracts were more effective against sapstaining fungi at minimum concentrations (0.10-1.0 %) used in 2 % (malt extract agar) medium. Three Chikusaku-eki (Chikusakueki-I, Chikusaku-eki-II and Chikusaku-eki-III) and 2 Mokusaku-eki (Mokusaku-eki-I, Mokusaku-eki-II) extracts were tested against 4 sapstaining fungal samples to evaluate the inhibition range on sapstaining fungal growth. Ophiostoma flexuosum, Ophiostoma tetropii, Ophiostoma polonicum and Ophiostoma ips were the sapstaining fungi used in this study against bamboo and wood extracts. The initial calibration of extracts was done by calculating the specific gravity, tar calculation and total organic content. The chloroform fractions of these extracts were analyzed by gas chromatographymass spectrometry and both the extracts contained 2,6 dimethoxy phenol, dehydroacetic acid and 2,3,5 trimethoxytoluene. Results revealed that compounds of Chikusaku-eki and Mokusaku-eki markedly inhibited fungal growth at lower concentration. The Chikusaku-eki and Mokusaku-eki have both antifungal, antioxidant properties and a potential to be used as natural preservative in wood industries. Wood slice tests displayed the effective role of both extracts in laboratory level.

Laboratory Evaluation of the Anti-stain Efficacy of Crude Wood Vinegar for Pinus densiflora

“…This strongly suggests that polyphenolic compounds affect the antifungal activity in addition to the previously reported acidic nature of wood vinegar (Velmurugan et al 2009). Nonetheless, mold can be removed easily by surfacing or planing, and does not discolor wood as severely as sapstain.…”

“…As alternatives, various natural products, such as plant essential oils (e.g., cedar leaf) and wood vinegar (Dawson-Andoh et al 2000), are being investigated, although currently these are not being produced commercially. Previous studies (Sulaiman et al 2005;Velmurugan et al 2009) have demonstrated that the presence of acids (mainly acetic acid) and phenols in wood vinegar made from bamboo and broad-leaved trees have antifungal properties useful to treat wood. Although Ikergami et al (1992) showed that wood vinegar, which contains guaiacol, cresol, 4-ethyl-2-methoxyphenol, and 2, 6-dimethoxyphenol, has good antifungal activity, there is, in general, very little scientific evidence regarding the antifungal properties of wood vinegar.…”

History and Use of Wood Pyrolysis Liquids as Biocide and Plant Protection Product

“…Velmurugan and co-authors [38,39] have published scientific evidence that wood vinegar made from bamboo and broad leaved trees were effective against sapstaining fungi at minimum concentrations (0.10-1.0%). Results revealed that compounds of Chikusaku-eki and Mokusaku-eki markedly inhibited fungal growth but the exact mode of action of active compounds need to be studied further.…”

Use of Botanical Pesticides in Modern Plant Protection

“…Many control technologies have been developed to inhibit fungi that cause discolouration on timber. It has been shown (Velmurugan et al 2009) that wood vinegar made from bamboo and broad-leaved trees is effective against sapstaining fungi. The results revealed that compounds of Chikusaku-eki and Mokusaku-eki markedly inhibit fungal growth and the product possesses both antifungal and antioxidant properties as well as potential for use as a natural preservative in woodworking industries.…”