Climate warming in the Arctic and the thawing of frozen carbon stocks are leading to uncertainty as to how bacterial communities will respond, including pollutant degrading bacteria. This study investigated the effects of carbon stimulation and temperature on soil microbial community diversity and explosive biodegradation in two sub-Arctic soils. Chitin as a labile carbon source stimulated overall microbial activities as reflected by increases in basal respiration (three to tenfold) and potential nitrification activity (two to fourfold) compared to unamended soil. This stimulation extended to 2,4-dinitroluene- (DNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)-degrading microorganisms either directly or via co-metabolic reaction mechanisms. A stimulatory effect of the incubation temperature (2, 12, or 22 °C) on these microbial activities was also observed, but the chitin stimulation caused greater shifts in the structure of the bacterial and fungal communities. The first reported occurrence of an associated role of chitinolytic bacteria belonging to Cellulomonadaceae and chitinolytic fungi belonging to Mortierellaceae in explosive biodegradation is described. This study found that sub-Arctic soil microbial communities were adapted to respond quickly to an increase in labile carbon sources over the range of temperatures used in this study. The warming climate in the Arctic could benefit explosive contaminated soil clean-up by providing non-recalcitrant carbon sources that stimulate overall microbial activity and correspondingly explosive biodegradation.

中文翻译：

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几丁质和温度对北极亚土壤微生物和真菌群落的影响以及六氢-1,3,5-三硝基-1,3,5-三嗪（RDX）和2,4-二硝基甲苯（DNT）的生物降解。

北极地区的气候变暖和冻结碳库的融化导致细菌群落如何应对（包括污染物降解细菌）的不确定性。这项研究调查了碳刺激和温度对两种亚北极土壤微生物群落多样性和爆炸生物降解的影响。几丁质是一种不稳定的碳源，与未经改良的土壤相比，其基础呼吸作用的增加（三倍至十倍）和潜在的硝化活性（两倍至四倍）反映了整体微生物活性。这种刺激直接或通过代谢反应机制扩展到了2,4-二硝基甲苯-（DNT）和六氢-1,3,5-三硝基-1,3,5-三嗪（RDX）降解微生物。孵育温度的刺激作用（2、12，或22°C）时也观察到了这些微生物的活性，但是几丁质的刺激引起细菌和真菌群落结构的更大变化。首次报道了属于描述了在爆炸性生物降解中属于门孢菌科的纤维素单胞菌科和几丁质分解真菌。这项研究发现，在该研究使用的温度范围内，北极亚土壤微生物群落适应于快速响应不稳定碳源的增加。北极变暖的气候可以通过提供非顽固性碳源来刺激爆炸性的土壤污染，这些碳源可以刺激总体微生物活动并相应地引起爆炸性的生物降解。