Antifungal activity in vitro using kraft-pulping crude black liquor and hydrothermal treatment black liquor against wood-decaying fungi

• Published in: Journal of wood chemistry and technology Vol. 43; no. 3; pp. 150 - 163
• Main Authors: Barbosa Abrantes, Karen Keli, Sete da Cruz, Rayane Monique, Barros, Thiago Vinicius, Rodrigues de Souto, Eliezer, Paes, Juarez Benigno, Cardozo-Filho, Lucio
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 02.05.2023; Taylor & Francis Ltd
• Subjects: Antifungal activity; Biological activity; Black liquor; Brown rot; Chemical composition; Decay fungi; Fungi; Fungicides; Gasification; Hydrothermal treatment; Inactivation; lignin kraft pulping; Phenolic compounds; phenolics compounds; Phenols; Preservatives; Pulp wastes; Pulping; White rot; Wood; Wood preservatives; wood protection
• ISSN: 0277-3813; 1532-2319
• DOI: 10.1080/02773813.2023.2200751

We investigated antifungal properties of two kraft-pulping liquors as potential environmentally friendly wood preservatives targeting in deterioration by white rot (WRF) and brown rot fungi (BRF). The in vitro antifungal activity of crude black liquor (BL) and the product from a hydrothermal gasification (BLW Supc ) process were investigated. Both products showed high bioactivity, with BL completely inhibiting the activity of WRF and BRF; 80% was entirely suppressed at low BL concentrations (5-10% vol/vol). Using the BLW Supc at 2.55% wt/wt, we achieved the same inhibitory effect as BL (15% vol/vol) for the two fungi. These antifungal effects can be explained by the composition of liquors that act as antioxidants, promoting enzymatic inactivation and inhibiting the growth of WRF and BRF. BLW Supc exhibited radical quenching activity against DPPH of 43.9%, and the BL, a phenolic content about 20 times higher (23.635 mg/L) than BLW Supc (2.093 mg/L), suggesting that antifungal activity of BL and BLW is related to their chemical composition. An opportunity demonstrated by this study is the reuse of BLW Supc as a protective treatment within a sustainable chain.