Microbial Degradation of Lignin, Plant Aromatics and Polychlorinated Biphenyls (PCBs) in Boreal Forest Soil

这项工作的目标是确定阿拉斯加北部森林土壤中的细菌，真菌和其他微生物的基因，这些细菌，真菌和其他微生物在各种芳香族（环状）化合物的生物降解中具有活性，这些化合物包括木质素，植物次生化合物和多氯联苯（PCB）。 将采用稳定同位素方法，该方法能够直接鉴定在自然条件下标记化合物生物降解所涉及的微生物和基因。木质素是地球上第二丰富的生物分子，占陆地生物量的25%。这种化合物和其他类似植物化合物的微生物降解是全球碳循环的关键组成部分，也可实际应用于化学性质类似的环境污染物（如多氯联苯）的清除。 阿拉斯加的内陆森林对这项研究特别有吸引力，因为当地的树种具有非常高的植物化合物浓度。 因此，可能存在大量与这些植物相关的微生物，它们可以有效地降解这些化学物质以及环境污染物。 所发现的微生物和基因可能对污染场地的清理有用，而培育这些微生物的植物物种可能会加速修复过程。 此外，这项工作将为北方森林的碳循环提供新的见解。

The goal of this work is to identify genes of bacteria, fungi and other microbes in Alaskan boreal forest soils that are active in the biodegradation of a variety of aromatic (ringed) compounds, including lignin, plant secondary compounds and polychlorinated biphenyls (PCBs). Stable isotope methods will be employed, which enable the direct identification of microorganisms and genes involved in biodegradation of labeled compounds under natural conditions. Lignin is the second most abundant biological molecule on earth, and comprises 25% of terrestrial biomass. Microbial biodegradation of this compound and other similar plant compounds is a critical component of global carbon cycling and also has practical application to the cleanup of chemically similar environmental pollutants such as polychlorinated biphenyls (PCBs). Alaskan interior forests are particularly attractive for this study since local tree species have extraordinarily high concentrations of the plant compounds of interest. Thus, there may be an abundance of microbes associated with these plants that can effectively degrade these chemicals as well as environmental pollutants. The microbes and genes identified may be useful for the cleanup of polluted sites, and growing plant species that foster these microbes may accelerate the remediation process. Furthermore, this work will provide new insight into carbon cycling in the boreal forest.