Antimicrobial Activity of Organic Wood Preservatives Against Bio-deterioration Fungi: Minimum Inhibitory Concentration (MIC) via Spiral Gradient Endpoint (SGE) Test

摘要

Efficient, reproducible, and sensitive procedures for screening antimicrobial activities of biocides are highly desirable. The goal of this study is to use Spiral Gradient Endpoint (SGE) agar plate test to measure the minimum inhibitory concentrations(MICs) of seven organic biocides against wood degrading fungi. The SGE method enjoys time and material advantages compared with conventional doubling dilution methods in agar or broth. The results compared the efficacy of 3-Iodoprop-2-yn-l-yl butylcarbamate (IPBC), chlorothalonil (CTL), 5-chloro-2-methyl-4-thiazoline-3-ketone and 2-methyl-4-thiazoline-3-ketone (CMTT/MIT), 2-Octyl-2H-isothiazol-3-one (OIT), propiconazole (PPZ), 4,5-dichloro-2-N-octyl-4-isothiazolin-3-one (DCOIT), and fenpropimorph (FPM)against mold fungi (e.g., Alternaria alternata, Aspergillus niger, Cladosporium cladosporioides, Penicillium citrinum, and Trichoderma viride), sap stain fungus (namely, Aureobasidium pullulans), and various wood decay fungi (including Coniophora puteana, Chaetomium globosum, Gloeophyllum trabeum, Postia placenta, and Trametes versicolor). The findings are in agreement with previous studies indicating the SGE method is a viable procedure to compare the relative antimicrobial activities between organicwood preservatives in a timely manner.