Abstract
This study constitutes the first attempt to examine the microbial diversity in New Zealand groundwater samples using a culture‐ and cloning‐independent technique. In this investigation, 18 distinct terminal restriction fragment length polymorphism (T‐RFLP) peak profiles were generated from groundwater samples collected from various sites and aquifers in the Hutt Valley and the Wairarapa. Most peak profiles were similar, implying only small differences in microbial community structure in the groundwater samples collected, and relatively low microbial diversity compared to non‐aquifer water samples. Nonetheless, subtle but systematic differences in T‐RFLP peak profiles were observed between the aquifers and, in some instances, for groundwater samples collected at different locations within a single aquifer. Differences in the peak profiles appeared to be related to groundwater chemistry, particularly to concentrations of iron, manganese, nitrogen, and sulfur.