Cryoconite holes (cylindrical melt-holes on the glacier surface) are important hydrological and biological systems within glacial environments that support diverse microbial communities and biogeochemical processes. This study describes retrievable heterotrophic microbes in cryoconite hole water from three geographically distinct sites in Antarctica, and a Himalayan glacier, along with their potential to degrade organic compounds found in these environments. Microcosm experiments (22 days) show that 13–60% of the dissolved organic carbon in the water within cryoconite holes is bio-available to resident microbes. Biodegradation tests of organic compounds such as lactate, acetate, formate, propionate and oxalate that are present in cryoconite hole water show that microbes have good potential to metabolize the compounds tested. Substrate utilization tests on Biolog Ecoplate show that microbial communities in the Himalayan samples are able to oxidize a diverse array of organic substrates including carbohydrates, carboxylic acids, amino acids, amines/amides and polymers, while Antarctic communities generally utilized complex polymers. In addition, as determined by the extracellular enzyme activities, majority of the microbes (82%, total of 355) isolated in this study (Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria and Basidiomycota) had ability to degrade a variety of compounds such as proteins, lipids, carbohydrates, cellulose and lignin that are documented to be present within cryoconite holes. Thus, microbial communities have good potential to metabolize organic compounds found in the cryoconite hole environment, thereby influencing the water chemistry in these holes. Moreover, microbes exported downstream during melting and flushing of cryoconite holes may participate in carbon cycling processes in recipient ecosystems.

低温洞穴（冰川表面的圆柱形熔洞）是冰川环境中重要的水文和生物系统，可支持多种微生物群落和生物地球化学过程。这项研究描述了南极洲三个地理上不同的地点和喜马拉雅冰川中的暗孔岩孔水中可回收的异养微生物，以及它们降解这些环境中发现的有机化合物的潜力。微观实验（22天）表明，常温微生物可生物利用冰冻洞内水中13-60％的溶解有机碳。冰冻孔水中存在的有机化合物（如乳酸，乙酸盐，甲酸盐，丙酸盐和草酸盐）的生物降解测试表明，微生物具有良好的代谢新化合物的潜力。在Biolog Ecoplate上进行的底物利用率测试表明，喜马拉雅样品中的微生物群落能够氧化多种有机底物，包括碳水化合物，羧酸，氨基酸，胺/酰胺和聚合物，而南极群落通常利用复杂的聚合物。此外，根据细胞外酶的活性，本研究中分离出的大多数微生物（变形杆菌，拟杆菌，硬毛，放线菌和担子菌）（82％，共有355种）具有降解多种化合物（如蛋白质，文献记载有在冰晶洞中存在的脂质，碳水化合物，纤维素和木质素。因此，微生物群落具有极好的潜力，可以代谢在超低温孔环境中发现的有机化合物，从而影响这些孔中的水化学性质。此外，在冰晶孔的熔化和冲洗过程中向下游输出的微生物可能参与受体生态系统中的碳循环过程。