The Usual Suspects: Fingerprinting Microbial Communities Involved in Decay of Treated Southern Yellow Pine

摘要

Current standards for soil-block testing have long been based on the effectiveness of preservative systems against only a small number of wood decay fungi and even fewer bacteria. Culture-independent molecular methods offer simple, reproducible meansto obtain a more holistic view of the microbial communities that colonize wood throughout the decay process. By using a culture-independent PCR-based method called terminal restriction fragment length polymorphism (T-RFLP) analysis, we were able to detect shifts of fungal and bacterial communities in wood treated with sub-lethal concentrations of ACQ-C and CTN. T-RFLP takes into account all species of a taxonomic group and creates a community profile or "fingerprint," where each peak in the profile represents a unique species. Both compounds appeared to change the patterns of bacterial succession completely, so that beginning and ending communities were significantly different in regard to species composition. Fungal species community structure was initially changed, but became more similar to untreated controls over time, presumably as the preservatives were depleted from samples. Subsequent depletion analysis found >60% depletion of preservatives from treated field stakes after 15 months exposure. Further modification to this process will eventually enable us to accurately identify fungal and bacterial species making up the microbial communities found in treated and decaying wood and offer new insights into the decay process.