Cowan, Don A.Rapley, JoanneDept. of BiotechnologyFaculty of Science2013-09-272024-05-092008/10/092008/10/092013-09-272024-05-092006https://hdl.handle.net/10566/13262Magister Scientiae - MScThe microbial life of sub-Antarctic islands plays a key role in the islands ecosystem, with microbial activities providing the majority of nutrients available for primary production. Knowledge of microbial diversity is still in its infancy and this is particularly true regarding the diversity of micro-organisms in the Antarctic and sub-Antarctic regions. One particularly important functional group of micro-organisms is the diazotrophs, or nitrogen-fixing bacteria and archaea. This group have not been well studied in the sub-Antarctic region, but play an important role in the nutrient cycling of the island. This thesis explored the diversity of nitrogen-fixing organisms in the soil of different ecological habitats on the sub-Antarctic Marion Island.enNitrogen-fixing microorganismsNitrogenFixationSoil microbiologyThesisUniversity of the Western Cape