Effects of chlorothalonil (CTN) and butylated hydroxytoluene (BHT) on microbial communities involved in the deterioration of wood using T-RFLP II: Results from field studies
G T Kirker, M L Prewitt, S V Diehl
The effects of Chlorothalonil (CTN) and Butylated Hydroxytoluene (BHT) on microbial species diversity in wood and the surrounding soil are being assessed by Terminal Restriction Fragment Length Polymorphism (T-RFLP). CTN was selected as a trial organic wood preservative, and the non-biocidal BHT was evaluated for its synergistic effects with CTN. ACQ-C was a positive control and untreated SYP stakes were negative controls. Tests were installed at two separate field sites in MS that represent two different AWPA hazard zones. Samples were taken every 3 months over a 15 month period and visually evaluated for termite attack and decay. Samples were processed and whole genomic DNA was extracted for molecular analyses. Upon initial amplification of DNA using both specific and general primers, the presence or absence of target fungi was confirmed using gel electrophoresis. We are currently using T-RFLP to analyze the patterns of microbial colonization over time and in response to external stimuli (i.e., wood preservative treatment) to identify potential shifts in microbial community. Preliminary results indicate that the presence of non-basidiomycete fungi (i.e. molds, stains, and soft rots) are uniformly distributed throughout the samples regardless of treatment, while basidiomycetes are less common and severe decreases in overall basidiomycete populations occurred during periods of drought at both test sites.
Keywords: butylated hydroxytoluene (BHT), chlorothalonil (CTN), microbial community analysis, Terminal Restriction Fragment Length Polymorphisms (T-RFLP), wood decay microorganisms